Back years ago when I taught myself electronics I bought one of the multi purpose board kits you can use to make 200 or so projects. When I played with a 555 that was the most amazing chips ever. Make timers to turn on and off at different times.! Once made a timer that took a month to turn on. After calculating the resistance and caps it was put in the living room and did nothing. Just sat there waiting to trip on. The wife thought I lost my mind. One Saturday about 4pm it came on. The timing was about 6 hours different from what I calculated. But, it was amazing a $1 circuit went off that close after 32 days. And I made it do that! The wife really thought I had lost it then. 😂
@@dougtaylor7724 In the late 70s a colleague did a industrial controls dosing pump driver which used a simple RC timer with insane long period and being inexperienced, he didn't realise after it left assembly line no one in Functional Test wanted to wait a week ten days whatever it was. So the boss had to change the timer to something actually measurable and added a CMOS divider IC patched under PCB. We called the guy The 555 Kid after that.
It is normally not a good idea to try and make very long delays (say greater than an hour) with a 555 directly because leakage in the capacitor tends to dominate the operation at such low charging & discharging currents, and the circuit is very sensitive to noise close to the comparator trip points. Adding a divider (as also suggested) makes operation much more dependable. Still, I had great fun s a kid learning these things for myself!!!
It’s exactly this kind of thing that we dreamed the internet would do for us - let people freely share their talents and knowledge with each other. Great explanation and video! Taking the time to briefly explain how the comparators worked and how the flip-flop worked is the exact kind of thing someone who doesn’t have natural teaching ability would have skipped completely.
You just have to wade through the ai generated fake videos, completely lose your privacy to multiple gigantic corporations and be completely unsure if your even talking to a real person since 25% of Internet traffic is scammy bots and another 25 is supposed good bots
This is the best explained 555 timer video ever. I understand what it does already high level and how to figure out the numbers but I have never seen all the internals so completely discussed and stepped through like you did. Brilliant work! Absolutely love electronics so throughly explained with real world results like this. Keep it up! And thank you for a more indepth understanding.
I agree I've been doing electronics as a hobby since the late '80s and read many articles on this IC Today I understood, for the first time, why a 555 can't give perfectly symmetrical square waves
PLEASE I am BEGGING explain op amps like this. I feel like a BARELY understand them and this video made me feel like I can explain a 555 to a toddler!!
I think this is an excellent explanation of op amps, at least when they don't have any direct feedback loops. Op amps get weird (and interesting) when there is a feedback loop involved. I can't remember who explained it or even the specific circuit configuration, but when the feedback loop is involved, "the opamp will do as much as it can to equalize the input voltages" and that's what stuck with me. I look forward to Paul's explanation of opamps because I think it'll be even more clear than that.
@@JamesHarrThe way that I learned op amps was that the op amp has variable gain internally and through magic will change the output voltage to make the two inputs equal. Then assuming the two equal inputs, you can find the desired output voltage. Slap on a capacitor or inductor and you now have an integrator or differentiator
I have kinda hated the 555 for decades because I could just never really wrap my head around how it worked. This is the first time it’s been explained in a way that makes sense. Well done!!
this is the first time this chip has ever made sense to me, i never understood what it was doing inside. it was always explained to me as how to *use* it, not how it *works*. thank you so much!!
@@paulpkae oh this was an insta-subscribe for me, you've solved something that's been a mystery at the back of my mind since the '90s, where i felt like it was just my fault for not getting it. and i just never realised it could actually make sense
I am an Electrician; the inner workings now make a lot more sense , got the fundamental's of electronics but never really applied my mind , a great lesson . Thank You.
Great video. Back in 1977 I was a diagnostic technician with a computer line printer company in Woodland Hills CA. The product was a very complex electro mechanical machine loaded with 555 timers. The 555 circuits were one of the highest failing components in the very complex machine. Frequently the capacitors would fail but sometimes the 555 would fail. Over time the design engineers began replacing the 555 timers with counters as they were more reliable and more precise. Excellent video, Thanks.
I have very little experience in electronics, so no idea why the algorithm offered me this video, but I watched the whole thing, learned a bunch and thoroughly enjoyed myself. That says a lot about the accessibility of this video
Almost the same here, I add seen videos about this subject before but not a electronics guy my self and I did learned a bunch with this one, even thou I don't think I will ever use this knowhow, at lest it demystifies computer tech to me.
This might well be the best explanation of an electronic component I have ever seen. This is "Electronics for Dummies" which is exactly what I need. I just went to his main page hoping and praying that he had a complete "Learning Electronics" tutorial but alas...😥
More like electronics for someone who is casually familiar with how electricity works. If someone was truely uneducated about any electrical theory, this video would be useless. That being said, this video explaining a 555 timer is better than any other video I have seen on the subject.
Hi thanks for the comment. My channel is quite new and small at the moment, but I have much bigger plans for it. and any more videos will be coming. Please make sure you Subscribe if you want to support. Thank you.
60 y. o. here... same. Designed and built a digital clock around it at 15. With the additional 74something nand gate ttl chips, it had the accuracy of 1 min per hour, and drained C batteries in a couple of hours...
Of course it is still around! I've got a bunch of them in my drawer of digital chips, along with my TTL and CMOS series chips. I first started tinkering with this chip from the TTL Cookbook, author Forrest Mims published by Tandy/Radio Shack. I've still got my copy of that book along with a bunch of chip pack cardboard "data sheets" stapled to the inside cover of of this book. Back in the 70s/80s, getting data on chips was hard. You kept those precious package data backs, and was very familiar with the Reader's Guide to Periodic Literature, and microfiche film at libraries to get data. Now it is just a Google search away, or a visit to Digikey! Technology has made some things easier.
Is it just me? I understand every piece of the internals of the 555 as it is being explained. I can understand how one component works with the next component. I can sorta understand the relationship of 3 components. After that my brain is just not big enough to put it all together. There is just a certain amount of complexity that is inherent to electronics. It could not be presented any better or simpler terms. This was a great video. I don't see how it could be explained any better. At some point I feel like I have to give up and just accept how it is used as a basic building block in circuits.
Thanks for the great comment. Electronic circuits can at first seem daunting, but they are only really a collection of simple building blocks put together.
I find them really useful too! There’s an online electronics simulator called Falstad that uses gradients for voltage and animation speed for current, and I find it extraordinarily helpful in understanding how circuits work.
I have to say this is THE most well done, clearly explained explanation of a 555's operation I have ever seen... and I've seen a LOT! I especially liked how you showed the actual charge/discharge of the capacitor on your 'scope. Nice touch! It's nice to see you explain that, on it's own, the chip is NOT a timer at all... it requires external components to become one. I had also heard that the designation (555) came from the 3 5K resistors in the voltage divider chain. I hope whoever invented this wonderful chip got some HUGE recognition for it. It has probably had the longest useful life of any chip on the planet! Over 50 years!!!
this is honestly the best explanation I have seen on the 555 and its operation. The explanation + visuals + calculations + breadboard + scope with comparison = awesome. I like that math!
I've had a little book called 555 and it's applications for literally decades - never got around to reading it, now I am seriously going to read it - yours is probably one of the best, if not the best explanation of electronics I have ever encountered. SUBSCRIBED!
What an amazing video. I have watched probably 2 dozen 555 videos recently, none are better than this. Visuals are great. Was also a very good explanation. You managed to make an entertaining and informative video on something that already has a lot of videos on it but with a unique and useful twist. E.g. I never took the time to figure out exactly how the astable mode works, and I'm very glad you walked me through it here. I haven't seen anyone else do that, and I'm glad you did. I cant wait to see see your other 555 videos that you mentioned at the end. Thanks for sharing.
like in the comments already i to never saw a video so well explaned about an electronic divice. fantastic. i wish more people would do it like this on more components or cicuits. its fantastic for biginners and hobby. thank u so much.
That was the absolute BEST explanation of the 555 chip. As a wannabe EE major in college - I gave up on the math and continuous curves and chose CompSci instead. However - if you were my teacher, I definitely would have stayed in. Brilliant!
Great video, explained better than my tutor 30+ years ago.. Just for laughs a quote "The 555 timer IC's name is said to come from the three 5 kΩ resistors within the chip, but the designer, Hans Camenzind, says the number was chosen arbitrarily. Camenzind said that the name was chosen by Art Fury, the marketing manager, who thought the circuit would sell well." I would say to that if the designer says so then so it is i have always gone by, the early chips actually had a very small 555 engraved somewhere within. Also to note there are much better and stable oscillator chips, but obviously much more expensive. 555 is great for hobby work, when you start to get into exact frequencies then you require more sophistication.. Loved this video..
Brilliant video. I was surprised that I could watch this length of video on the venerable 555 and not find my mind wandering. It's a testament to the ability to teach and keep people engaged in the content. I really appreciate breaking down the pins and how they are related without just glossing over why a given pin is connected to a specific point in the circuit. The color coding of the internal and external voltages along with the logic level changes definitely made it easier to follow what was going on. Bonus points for building up the bench demo from a couple LEDs to the oscilloscope traces that took the diagrams from a simulation to the real world.
Thanks for your comment. It took quite some effort to put this together to be honest, but I am please with the outcome, especially all the comments like yours. Please remember to Subscribe, if not already. 😁
I'm a software engineer who is trying to learn electronics. After a fair bit of research, I have to say this video has done the best job so far of giving me that "aha!" moment. When you asked what component could be used to charge/discharge, and I correctly guessed capacitor, I couldn't help but fist pump in excitement! Thank you for your work. I look forward to learning much more from you.
I've always been interested in electronics but as a kid it was hard to get all the right components. Now I've grown up and watch this video at 3am, I guess it's never too late to start learning a new hobby, thank god nowadays you can get any components and there are great channels like yours that help a lot.
I played with electronics a lot as a kid and throughout highschool courses. Now at 61 with more free time on my hands I'm picking up where I left off. 😉 Great video! First time I really understood what's going on behind each pin and what I can use it for.
Brilliant explanation! It's not often I find any material that blends theory and practice so well. Your shifts between diagram, breadboard, and oscilloscope are beautifully timed in the video; this is the clearest I've ever seen a 555's operation described. Thanks for taking the time to craft such an excellent video!
Thank you for this explanation and demo! I only really learned how to do microcontrollers with electronics so finding out other uses for simpler components is useful. One use for the 555, instead of a capacitor and voltage divider, you could use a thermistor to vary the threshold voltage based on temperature and tie the output to a relay to turn on a heater, you have made a simple bang-bang control loop.
Needed a refresher course on the 555 and wow..did I get one. Excellent tutorial and graphics, hands on. Explained well and perfectly and real time experiment. Thank you!
makes me feel old , i was playing around with 555's 50years ago. but interesting talk
3 місяці тому+1
You're probably fed up already by all the praise, but you're such a great explainer. On top of that, your visualisations are very clear and super informative. Brilliant channel! I wish I had an electronics teacher like you back in my uni days.
That was an enjoyable trip down memory lane :) I once met a very excited chapin the gents of a Southampton pub who had designed the timer circuit for the hot air hand dryer using an NE556 and for some reason, he really wanted to explain the circuit to anyone who would listen.
So the timer part is the RC circuit, and the 555 is essentially an elaborate device that is doing the switching and the discharging of the RC circuit. I see. Just a disclaimer, I came into this video as someone who knows what the 555 is used for and what the basic electronic components do (and a healthy bit of microcontroller electronics too, I suppose), and right now I am confident I can, with what you covered and two potentiometers replacing the resistors, drive a servo. Before this, I would've been forced to program a dev board like an arduino or ESP to do it. Thank you for making this video! It's as simple as it needs to be without dumbing it down to just a set of instructions.
Thanks for the comment. Micro controllers are great fun, but also a stepping stone into the wider world of electronics. In most circumstances, using electronic components to achieve your requirements is normally the better solution.
Thanks for making this video! I had 3/4 of an idea how these chips worked, but now it's crystal clear. You are a great teacher. I hope you keep making these vids. Cheers!
Best video and explanation I've seen on all of UA-cam, and much much much better than anything from University. Especially with the Images and gradients. Subscribed!
This is by far one of the best explanations for an electronic component that I've ever seen. Your intro burst my ears (I was wearing earphones) but it was totally worth it for how good this video was and how well I was able to understand what you were teaching. Thank you for this video ❤
Thanks. Yes a few people have mentioned the intro volume. I had tweaked by OBS settings prior to recording to try and improve the clarity and forgot to normalise my intro recording. Other than that, I'm glad you made your way through it and found it of use.
That was fun...like you, I was there at the dawn of digital circuitry and having build dozens of 555 circuits, I immediately realized the purpose of your click bait. I congratulate you on your patience in following through the explanation of how it works. Somewhere around here is a red book with about 100 555 projects from turn signals for a motorcycle to windshield wiper auto sweep, etc. Very effective post...Great Job!
@@irpiyaprach9555 thanks for the comment. Glad you liked it. Although it's free, you can help by Subscribing and Liking. It makes all the difference, thanks.
Wow, this brings back memories. When I was fresh out of school in the late 70s and an engineer with Motorola, I was assigned the task of designing a test fixture to ensure that capacitors installed in antennas under production were within limits. The solution I came up with was to use three 555 timers with two of them using precision components at both ends of the allowable capacitance range. The third timer operated with the capacitor to be tested. The idea was that if the capacitor under test was within limits, its 555 timer would trigger after the one operating at one end of the range, but before the one at the opposite end. If the capacitor under test was within limits, additional logic circuitry would turn on a green light, and if it were not, a red light would come on. It worked and I got no complaints from the factory, but, even now, always wondered just how accurate it was.
Thanks for the comment. Yes all electronics can be said to be analogue. A 1 or 0 is only a voltage threshold at the end of the day. Just to add, from my experience, everything also always boils down to Ohms law if you drill down enough.
First video I've seen of yours and its great. Very clean, no blurry camera stuff, WELL explained, excellent format of diagrams and bench testing. Liked and Subscribed!
Great in-depth video on the 555 in astable mode. A follow up video could cover monostable mode. This would explain why the designer of the device didn't just connect trigger and threshold together inside the chip.
Thanks for your comment. I do intend doing some follow up videos to this. My very next video however is going to be a review of a nifty digital microscope.
The first chip I ever played with, because it was useful, and cheap (I miss Maplin) . blew a few up. know it inside out, upside down and backwards. This is a great explanation to the next generation of 555 users.
In my trade, Maplin was a handy local store for whatever construction site we worked on, if you needed something urgent. However, the walk from site to the nearest Maplin soon become known as "The Walk of Shame" because it meant you had not planned your works properly.😆
A good beginning explanation of the 555. Thank you for your time in presenting this lesson. Will follow up with the other lessons you offer. Thanks again! 👍🏻
This is a brilliant explanation of how the 555 can be used and _why_ it functions as it does. I appreciate you showing them in animation as well as on the bench and with the scope. I wish I had this instruction when I was in school. This all being said, you didnt really dive into your thesis on why this chip "isn't a timer". I'd say that this chip is similar, conceptually, to the escapement mechanism of a clock if used in such a circuit. It can convert an analogue oscillation into a digital count, and even if it can only count to one, isnt that the absolute basis for timing? In any case, the bait worked and I'm here for it, have your engagement, I'll be back for more no doubt 🤣
Thanks for the comment. Controversial thumbnails jump out at people and grab attention 😄 The main purpose of the video was to demonstrate how the internal building blocks work, in conjunction with the components you install around the chip, to make it into a timer.
It is worth mentioning that the Control Voltage *pin, #5, is also known as the Pulse Width Modulation pin.* I have had great fun playing with that function, even turning a CMOS 555 into a Digitial Mode audio amplifier with pin 5 as the audio input! A couple of extra components are needed beyond the usual few for a simple timer: an external transistor to make the duty cycle 50% ON and 50% OFF, plus an inductor to knock out the high frequency elements of the output signal, and a small capacitor on pin 5 to give DC isolation from the audio source. I set the oscillation frequency to be 2 MHz, which is only possible with the CMOS 555. That meant each wave of the audio input was _in effect_ 'sampled' 100 times (for 20 kHz audio), and 100,000 times (for 20 Hz audio), giving high fidelity to the *_implicit_** A-to-D conversion* and to the audio output. 🙂
Very nicely explained 👍 In fact, I rate this video excellent. I found myself watching all the way through even though I already knew how it worked. And have used it in many circuit configurations. Including an opposite polarity one shot monostable pulse generator (to generate a reset pulse for another chip). The number of different circuit configurations shows how flexible it is.
I agree this is one of the best explained 555 timers vides that I have seen, I remember looking at the timer at college and it seem difficult to understand as we had was the RS data sheet written by electronic professors
I may be wrong, but I thought this was a perfect video. I’ve never given that compliment before, though, to be honest, Veritasium deserves and others deserved it. Great job. No one should ever replicate this video.
Lack of interest? You commented 3 hours after it was published. Give it time, Im sure this vid will get a lot of views .. or at least it should, considering how good it is.
People say it wasn't named after the 5K resistors because that's what the inventor of the 555 said in an interview. It was named by a marketing fellow who thought "555" was catchy. Brilliant video, BTW.
@@paulpkae You may think it is too coincidental but it don't know any reason to think it is not a simple coincidence. Historically there was no logic for how these early ICs got their number designations. As far as I know it was generally mostly chance. The 556 is essentially two 555s in a single package. There is no difference in the resistor voltage divider. I don't recall hearing anyone speculating where the name came from back in the 70s or early 80s. No one questioned where 7404 got that designation either. Engineers just like to number things.
i once worked for a small company whose main "electrical engineer" only knew relay ladder logic. I designed a simple 555 circuit operating in a sequence to signal solenoid air valves to open to blow dust from a multiple dust bag system into the waste bin. Worked like a champ. They thought it was the cat's meow.
Although my mind is mush watching this video I actually really understand it the way you explained it at the end. I just stumbled across the video and it seemed interesting especially the way you explain. I love seeing your real world example after your lecture because it lets me see it in action which I need to be able to get an understanding.
Great description and video! 555 was developed by Signetics founded by some former Fairchild Semiconductor Engineers (like Intel was). I worked at National Semiconductor (just around the corner from the Signetics Plant) and we called it the "Triple Nickel" at least in our department(Test Engineering) when NSC decided to second source the 555. Still have a Signetics Apps Book on my bookshelf and a very useful chip when the only option was a bunch of TTL Logic to do timing when you could get away with only a few external components back in the day.
I've never stuck through with properly learning electronics on this level, but have found reasons to solder and build anyway. This was brilliant. Perhaps I'll end up brushing off one of my kits!
In 1980 I used a thermistor in the timing circuit to produce a temperature sensitive pulse duration. That pulsed a milliwatt CW transmitter so I could remotely get temp data by monitoring time between pulses. That got implanted in free ranging woodchucks so we could monitor location and hibernation status.
I can only agree with the many praising commentators, and say that this is an extraordinarily well thought through and presented video. It "breaks down"the subject into basic parts, functions and concepts, and then explains all of them clearly and succinctly. As a complete "electronic ignoramus" I do have a couple of questions that would be very greatful if someone with a little more knowledge could answer.: Firstly: when a "pin goes high" does that mean that it's pulled up to same voltage as "Vcc" ? If not then what voltage ? Secondly: what if anything happens if you put a voltage on the "control voltage pin" that is less(lower) than ⅔ of "Vcc" ?(meaning that it is lower than the voltage that is supplied by the "voltage divider" to "comparator#2") will it lower the voltage of the"comparator pin" to the "control voltage" by continuously "sinking current" from Vcc ? Many thanks for this fantastic video "lesson" :) Best regards P.s. If I were to attempt to give any, hopefully constructive, criticism it would only be that the clips where you show your "real circuits" and point to the relevant components and connections possibly could have been benefitted by some "zoomed in shots" of some of the smaller details. Again many thanks
Hi thanks for your comment and great questions. 1) When the pin goes High, the output is indeed driven to the supply voltage. But, most 555 chips (an other ICs) cannot drive their outputs completely to the supply voltage and in reality will be a slightly lower voltage, especially if you place a sizeable load on the output pin. 2) If the control pin is at a lower voltage than 2/3 supply, then it will be pulled down 'close to' that voltage. But this will be affected by the output impedance of the secondary supply and how well it can sink current. Note the 1/3 voltage leg, going off to comparator 1, is also affected by the control pin voltage.
Nice to hear this explanation lives on.. PNP & NPN Was one of the first things I was taught when I was in a YTS T.V. Engineer training apprentice. ~1986 + Point iN Please & Not Pointing iN. Project building hobby led to a self taught knowledge of the voltage polarity workings for basic switch amplification. ie. PNP = A Positive on the Emitter then the base should be held Negative 0v to switch the collector through to the Positive. NPN = A Negative on the Emitter then the base should be held Positive to switch the collector through to the Negative. Basic relay type stuff. But also a general rule in amplifiers but that gets more datasheet reliant for HFE values etc. Cheers.
I learned about the 555 in the late 70s. By then, I had played with the usual configurations (blinking LED, speaker sound, etc). Shortly after, a photographer friend asked me if I could build him a timer for his photography enlarger lamp. He wanted it to be controllable from just a few seconds to well over a minute, with strictly repeatable results. So I had this crazy idea, which I wasn't totally sure that would work: I wired two rotary, 10-position switches and associated potentiometers (trimmers, actually) in series so that the resistances of "high-value" (tens of seconds) trimmers would be added to that of the "low" (seconds) trimmers. And it worked, too. With that arrangement, I could set the switches to any discrete time interval between 0 (lamp on for only as long as the start button was pressed) and 99 seconds. The 555 timer output was routed through a transistor to a 120V relay, which drove the lamp. The photographer friend used this for many years, and I still think it was one of he coolest things I've made as an electronics hobbyist.
Wauw, even though there are over 300 reactions telling you this is the best explanation ever seen, I'll just add another one. What a great explanation, one of the best 30 minutes on UA-cam :-). Thank you for sharing, I've subscribed!
Back years ago when I taught myself electronics I bought one of the multi purpose board kits you can use to make 200 or so projects.
When I played with a 555 that was the most amazing chips ever. Make timers to turn on and off at different times.! Once made a timer that took a month to turn on. After calculating the resistance and caps it was put in the living room and did nothing. Just sat there waiting to trip on. The wife thought I lost my mind. One Saturday about 4pm it came on. The timing was about 6 hours different from what I calculated. But, it was amazing a $1 circuit went off that close after 32 days. And I made it do that! The wife really thought I had lost it then. 😂
Haha! Brilliant! that made me laugh, thank you.
Your timer was 99.24% accurate. Well done. Your wife does not deserve you.
@@dougtaylor7724 In the late 70s a colleague did a industrial controls dosing pump driver which used a simple RC timer with insane long period and being inexperienced, he didn't realise after it left assembly line no one in Functional Test wanted to wait a week ten days whatever it was. So the boss had to change the timer to something actually measurable and added a CMOS divider IC patched under PCB. We called the guy The 555 Kid after that.
It is normally not a good idea to try and make very long delays (say greater than an hour) with a 555 directly because leakage in the capacitor tends to dominate the operation at such low charging & discharging currents, and the circuit is very sensitive to noise close to the comparator trip points. Adding a divider (as also suggested) makes operation much more dependable. Still, I had great fun s a kid learning these things for myself!!!
Fantastic...
ya u can do all kinds of fun stuff with just a very few chips...
It’s exactly this kind of thing that we dreamed the internet would do for us - let people freely share their talents and knowledge with each other. Great explanation and video! Taking the time to briefly explain how the comparators worked and how the flip-flop worked is the exact kind of thing someone who doesn’t have natural teaching ability would have skipped completely.
You just have to wade through the ai generated fake videos, completely lose your privacy to multiple gigantic corporations and be completely unsure if your even talking to a real person since 25% of Internet traffic is scammy bots and another 25 is supposed good bots
Thanks. I find sharing knowledge to be very rewarding. All your comments make the effort all worthwhile.
Word!
This is the best explained 555 timer video ever. I understand what it does already high level and how to figure out the numbers but I have never seen all the internals so completely discussed and stepped through like you did. Brilliant work! Absolutely love electronics so throughly explained with real world results like this. Keep it up! And thank you for a more indepth understanding.
Many thanks for your great comment.
I agree
I've been doing electronics as a hobby since the late '80s and read many articles on this IC
Today I understood, for the first time, why a 555 can't give perfectly symmetrical square waves
@@qlue7881 thanks for the comment.
A video on how to achieve 50% (or higher) duty cycle is coming, if that's what you mean.
😊😊👍👍🙇🙇🙇🙇🙍🏾♂️❤😅❤❤😮
I learned ot 0 years ago at a Junior College
Great professor.
PLEASE I am BEGGING explain op amps like this. I feel like a BARELY understand them and this video made me feel like I can explain a 555 to a toddler!!
Hi. Yes, an Op-Amp explanation will be essential content for my General Electronics collection. It is on my long list to do.
I think this is an excellent explanation of op amps, at least when they don't have any direct feedback loops. Op amps get weird (and interesting) when there is a feedback loop involved.
I can't remember who explained it or even the specific circuit configuration, but when the feedback loop is involved, "the opamp will do as much as it can to equalize the input voltages" and that's what stuck with me.
I look forward to Paul's explanation of opamps because I think it'll be even more clear than that.
@@JamesHarr challenge accepted 😲
@@JamesHarrThe way that I learned op amps was that the op amp has variable gain internally and through magic will change the output voltage to make the two inputs equal. Then assuming the two equal inputs, you can find the desired output voltage. Slap on a capacitor or inductor and you now have an integrator or differentiator
Excellent Suggestion....Op-Amps are analog devices, so they can be amplifiers, and used in combinations, they do so much more.
I have kinda hated the 555 for decades because I could just never really wrap my head around how it worked. This is the first time it’s been explained in a way that makes sense. Well done!!
Thanks for the comment. I'm glad you found the video useful.
this is the first time this chip has ever made sense to me, i never understood what it was doing inside. it was always explained to me as how to *use* it, not how it *works*. thank you so much!!
That's Great!
More videos on the 555 coming, so make sure you Subscribe. 😀
@@paulpkae oh this was an insta-subscribe for me, you've solved something that's been a mystery at the back of my mind since the '90s, where i felt like it was just my fault for not getting it. and i just never realised it could actually make sense
'PNP Points In, NPN Never Points In' Just wanted to thank you for helping me understand that better. Also the best 555 video I've found.
@@rosyspex great, glad you liked.
The mnemonic that stuck with me is “PNP - points in proudly”.
I am an Electrician; the inner workings now make a lot more sense , got the fundamental's of electronics but never really applied my mind , a great lesson . Thank You.
Excellent! Thanks for watching and thanks for the comment.
It's been decades since I fooled around with a 555. Thanks for the great explanation. Very clear and detailed.
Thanks for watching! And thanks for your comment.
Great video. Back in 1977 I was a diagnostic technician with a computer line printer company in Woodland Hills CA. The product was a very complex electro mechanical machine loaded with 555 timers. The 555 circuits were one of the highest failing components in the very complex machine. Frequently the capacitors would fail but sometimes the 555 would fail. Over time the design engineers began replacing the 555 timers with counters as they were more reliable and more precise. Excellent video, Thanks.
Thanks for sharing! Glad you liked the video.
I have very little experience in electronics, so no idea why the algorithm offered me this video, but I watched the whole thing, learned a bunch and thoroughly enjoyed myself. That says a lot about the accessibility of this video
Wow, thanks!
Almost the same here, I add seen videos about this subject before but not a electronics guy my self and I did learned a bunch with this one, even thou I don't think I will ever use this knowhow, at lest it demystifies computer tech to me.
This might well be the best explanation of an electronic component I have ever seen. This is "Electronics for Dummies" which is exactly what I need. I just went to his main page hoping and praying that he had a complete "Learning Electronics" tutorial but alas...😥
More like electronics for someone who is casually familiar with how electricity works. If someone was truely uneducated about any electrical theory, this video would be useless. That being said, this video explaining a 555 timer is better than any other video I have seen on the subject.
Hi thanks for the comment. My channel is quite new and small at the moment, but I have much bigger plans for it. and any more videos will be coming.
Please make sure you Subscribe if you want to support. Thank you.
@@robr4662 thank you.
@@paulpkaeSubscribed, thank you!!
I hate to burst your bubble, but you’re not a dummy. 😁
I am 61 an I am used the chip when I was 17. Didn‘t know this chip is still around. Nice!
It’s still all over the place.
Still going strong and now manufactured by many companies and in various form factors, TTL, CMOS. There's even a dual 555, namely the 556.
60 y. o. here... same.
Designed and built a digital clock around it at 15. With the additional 74something nand gate ttl chips, it
had the accuracy of 1 min per hour,
and drained C batteries in a couple of hours...
Of course it is still around! I've got a bunch of them in my drawer of digital chips, along with my TTL and CMOS series chips. I first started tinkering with this chip from the TTL Cookbook, author Forrest Mims published by Tandy/Radio Shack. I've still got my copy of that book along with a bunch of chip pack cardboard "data sheets" stapled to the inside cover of of this book. Back in the 70s/80s, getting data on chips was hard. You kept those precious package data backs, and was very familiar with the Reader's Guide to Periodic Literature, and microfiche film at libraries to get data. Now it is just a Google search away, or a visit to Digikey! Technology has made some things easier.
I am 31 and getting started into electronics. This chip is very useful and cheaper than programming and Arduino
Is it just me? I understand every piece of the internals of the 555 as it is being explained. I can understand how one component works with the next component. I can sorta understand the relationship of 3 components. After that my brain is just not big enough to put it all together. There is just a certain amount of complexity that is inherent to electronics. It could not be presented any better or simpler terms. This was a great video. I don't see how it could be explained any better. At some point I feel like I have to give up and just accept how it is used as a basic building block in circuits.
Thanks for the great comment. Electronic circuits can at first seem daunting, but they are only really a collection of simple building blocks put together.
your addition of the color gradients was a real game changer for me. thanks for this. Well done!
Thanks. An additional bit of effort can make a lot of difference.
I find them really useful too!
There’s an online electronics simulator called Falstad that uses gradients for voltage and animation speed for current, and I find it extraordinarily helpful in understanding how circuits work.
using this chip for 20 years and still learned something new. thanks!
Great to hear! Thanks for watching and taking the time to comment.
I have to say this is THE most well done, clearly explained explanation of a 555's operation I have ever seen... and I've seen a LOT! I especially liked how you showed the actual charge/discharge of the capacitor on your 'scope. Nice touch! It's nice to see you explain that, on it's own, the chip is NOT a timer at all... it requires external components to become one. I had also heard that the designation (555) came from the 3 5K resistors in the voltage divider chain. I hope whoever invented this wonderful chip got some HUGE recognition for it. It has probably had the longest useful life of any chip on the planet! Over 50 years!!!
Thanks for the comment, much appreciated.
I think this is the best video about how a 555 works I've ever seen.
Thanks so much.
this is honestly the best explanation I have seen on the 555 and its operation. The explanation + visuals + calculations + breadboard + scope with comparison = awesome. I like that math!
@@techtopics5782 thanks.
This is the clearest explanation of how the 555 timer works, that I’ve ever seen!
That's great. Many thanks for your comment, much appreciated.
I've had a little book called 555 and it's applications for literally decades - never got around to reading it, now I am seriously going to read it - yours is probably one of the best, if not the best explanation of electronics I have ever encountered.
SUBSCRIBED!
Brilliant! Thanks for the comment and especially for Subscribing too.
You can tell a lot of passion was put into this video to make it a clear explanation with lots of visual aids. Congratulations.
Many thanks and yes you're right, it was a lot of work to compile, but overall quite enjoyable and rewarding.
Never see a video about 555 well explain. Amazing. Keep me on screen to understand this chip, and how they work.
Glad it was helpful!
What an amazing video. I have watched probably 2 dozen 555 videos recently, none are better than this. Visuals are great. Was also a very good explanation. You managed to make an entertaining and informative video on something that already has a lot of videos on it but with a unique and useful twist. E.g. I never took the time to figure out exactly how the astable mode works, and I'm very glad you walked me through it here. I haven't seen anyone else do that, and I'm glad you did. I cant wait to see see your other 555 videos that you mentioned at the end. Thanks for sharing.
Many thanks for your comment. More videos coming......
The very best of lectures
I have listened to so many no one matches your style and ease of understanding. Thank you thank you thank you.
Thanks and welcome.
This is one of the cleanest explanations in an electronics video that I've seen, fantastic work!
Glad you enjoyed it! Thanks for the comment.
like in the comments already i to never saw a video so well explaned about an electronic divice. fantastic. i wish more people would do it like this on more components or cicuits. its fantastic for biginners and hobby. thank u so much.
thanks so much for your comment. I'm glad you found it useful.
That was the absolute BEST explanation of the 555 chip. As a wannabe EE major in college - I gave up on the math and continuous curves and chose CompSci instead. However - if you were my teacher, I definitely would have stayed in.
Brilliant!
Fantastic! Thanks for your comment, much appreciated.
Great video, explained better than my tutor 30+ years ago.. Just for laughs a quote "The 555 timer IC's name is said to come from the three 5 kΩ resistors within the chip, but the designer, Hans Camenzind, says the number was chosen arbitrarily. Camenzind said that the name was chosen by Art Fury, the marketing manager, who thought the circuit would sell well." I would say to that if the designer says so then so it is i have always gone by, the early chips actually had a very small 555 engraved somewhere within. Also to note there are much better and stable oscillator chips, but obviously much more expensive. 555 is great for hobby work, when you start to get into exact frequencies then you require more sophistication.. Loved this video..
Brilliant video. I was surprised that I could watch this length of video on the venerable 555 and not find my mind wandering. It's a testament to the ability to teach and keep people engaged in the content.
I really appreciate breaking down the pins and how they are related without just glossing over why a given pin is connected to a specific point in the circuit. The color coding of the internal and external voltages along with the logic level changes definitely made it easier to follow what was going on.
Bonus points for building up the bench demo from a couple LEDs to the oscilloscope traces that took the diagrams from a simulation to the real world.
Thanks for your comment. It took quite some effort to put this together to be honest, but I am please with the outcome, especially all the comments like yours. Please remember to Subscribe, if not already. 😁
A Masterpiece for electronics engineering teaching. Bravo!!
Wow, thanks!
I'm a software engineer who is trying to learn electronics. After a fair bit of research, I have to say this video has done the best job so far of giving me that "aha!" moment.
When you asked what component could be used to charge/discharge, and I correctly guessed capacitor, I couldn't help but fist pump in excitement!
Thank you for your work. I look forward to learning much more from you.
Great stuff! I have now visions of your joyous moment :)
I used one of these for a 1Mhz clock on a 6502 board I made. It worked just fine. Nice description, very thorough.
Very nice!
Finally someone explains the 555 in depht. Everything else I saw here about the 555 was only confusing gibberish. Thank you.
Thanks, glad you found it useful. Hopefully you Subscribed :)
I've always been interested in electronics but as a kid it was hard to get all the right components. Now I've grown up and watch this video at 3am, I guess it's never too late to start learning a new hobby, thank god nowadays you can get any components and there are great channels like yours that help a lot.
Glad you liked it, even at 3am in the morning :) Thanks for the comment.
I played with electronics a lot as a kid and throughout highschool courses. Now at 61 with more free time on my hands I'm picking up where I left off. 😉
Great video!
First time I really understood what's going on behind each pin and what I can use it for.
@@AlbertSA3 Great stuff. Hope it sparks some interesting projects for you.
Brilliant explanation! It's not often I find any material that blends theory and practice so well. Your shifts between diagram, breadboard, and oscilloscope are beautifully timed in the video; this is the clearest I've ever seen a 555's operation described. Thanks for taking the time to craft such an excellent video!
Glad you enjoyed and thanks for the great comment.
I love stumbling on subjects I forgot I had learned. This whole video brought me back to 20 years ago learning this from Mr. Guerin.
Glad you likes it. Hope the memories were good ones :)
Thank you for this explanation and demo! I only really learned how to do microcontrollers with electronics so finding out other uses for simpler components is useful. One use for the 555, instead of a capacitor and voltage divider, you could use a thermistor to vary the threshold voltage based on temperature and tie the output to a relay to turn on a heater, you have made a simple bang-bang control loop.
Thanks.
Needed a refresher course on the 555 and wow..did I get one. Excellent tutorial and graphics, hands on. Explained well and perfectly and real time experiment. Thank you!
Thanks, glad you enjoyed. Please be sure to Subscribe. More 555 videos coming and I will be ramping up on this channel in a few months time.
Adding my voice to all the others...absolutely brilliant job explaining and demonstrating the 555 timer.
Glad you liked it!
makes me feel old , i was playing around with 555's 50years ago. but interesting talk
You're probably fed up already by all the praise, but you're such a great explainer. On top of that, your visualisations are very clear and super informative. Brilliant channel! I wish I had an electronics teacher like you back in my uni days.
I will never get fed up of positive comments like yours. It inspires me to continue on, thank you.
This is by far the best explanation of the 555. I struggled to understand it , but this made it clear.
Thanks for the comment, much appreciated.
That was an enjoyable trip down memory lane :) I once met a very excited chapin the gents of a Southampton pub who had designed the timer circuit for the hot air hand dryer using an NE556 and for some reason, he really wanted to explain the circuit to anyone who would listen.
From my experience, those hand dryers must have the wrong size capacitors in them then . 😆
A good lesson for electronic students on solid state logic. Well done. When I went through school, everything was shown on a blackboard.
Thanks for the comment,
You are a terrific instructor. This was the first video of yours that I watched. I learned a lot. You earned a subscriber.
Many thanks for your comment and more so for Subscribing,
So the timer part is the RC circuit, and the 555 is essentially an elaborate device that is doing the switching and the discharging of the RC circuit. I see. Just a disclaimer, I came into this video as someone who knows what the 555 is used for and what the basic electronic components do (and a healthy bit of microcontroller electronics too, I suppose), and right now I am confident I can, with what you covered and two potentiometers replacing the resistors, drive a servo. Before this, I would've been forced to program a dev board like an arduino or ESP to do it. Thank you for making this video! It's as simple as it needs to be without dumbing it down to just a set of instructions.
Thanks for the comment.
Micro controllers are great fun, but also a stepping stone into the wider world of electronics. In most circumstances, using electronic components to achieve your requirements is normally the better solution.
Simple concise valuable explanation. Easy to follow, easily understandable; it all makes sense now. Thank you. Look forward to future videos.
@@halb1282 great! Thanks for your comment. Much appreciated.
Thanks for making this video! I had 3/4 of an idea how these chips worked, but now it's crystal clear. You are a great teacher.
I hope you keep making these vids. Cheers!
Thanks for watching and the comment, glad you found it useful. Yes more videos are coming, so make sure you Subscribe too 😁
Best video and explanation I've seen on all of UA-cam, and much much much better than anything from University. Especially with the Images and gradients. Subscribed!
Glad it was helpful! And thanks for Subscribing.
What an excellent explanation of the 555!
Many thanks. I am working on the next follow up 555 video this very moment.
This is by far one of the best explanations for an electronic component that I've ever seen.
Your intro burst my ears (I was wearing earphones) but it was totally worth it for how good this video was and how well I was able to understand what you were teaching.
Thank you for this video ❤
Thanks. Yes a few people have mentioned the intro volume. I had tweaked by OBS settings prior to recording to try and improve the clarity and forgot to normalise my intro recording.
Other than that, I'm glad you made your way through it and found it of use.
This is the first time I actually have a feeling I understood how this thing works. Thank you 🙏 (I’m a total noob)
Thanks, glad you found it useful.
Fantastic video, thanks. Brings back memories. The 555 was a jack of all trades. Maybe you could do a follow-up on all its other uses.
Thanks for watching and many thanks for the comment. More 555 videos coming....
That was fun...like you, I was there at the dawn of digital circuitry and having build dozens of 555 circuits, I immediately realized the purpose of your click bait. I congratulate you on your patience in following through the explanation of how it works. Somewhere around here is a red book with about 100 555 projects from turn signals for a motorcycle to windshield wiper auto sweep, etc.
Very effective post...Great Job!
Thanks, glad you like it.
Really well explained. This must have been one of the most " mysterious" circuits I came across when I was a youngster!
Thanks. Glad you enjoyed.
This is too good to be free, thank you for all your effort. Thank you man
@@irpiyaprach9555 thanks for the comment. Glad you liked it. Although it's free, you can help by Subscribing and Liking. It makes all the difference, thanks.
Wow, this brings back memories. When I was fresh out of school in the late 70s and an engineer with Motorola, I was assigned the task of designing a test fixture to ensure that capacitors installed in antennas under production were within limits. The solution I came up with was to use three 555 timers with two of them using precision components at both ends of the allowable capacitance range. The third timer operated with the capacitor to be tested. The idea was that if the capacitor under test was within limits, its 555 timer would trigger after the one operating at one end of the range, but before the one at the opposite end. If the capacitor under test was within limits, additional logic circuitry would turn on a green light, and if it were not, a red light would come on. It worked and I got no complaints from the factory, but, even now, always wondered just how accurate it was.
Is he daft? Nah just telling the truth 😊 Brings back many memories playing with 555 timers. Great presentation. 👍👍👍
Many thanks for the comment. Hope you have not stopped playing with electronics, you are clearly still interested.
Brilliant! It makes me admire the engineer who thought this up in the early days of digital electronics. Also confirms that all electronics is analog.
Thanks for the comment.
Yes all electronics can be said to be analogue. A 1 or 0 is only a voltage threshold at the end of the day.
Just to add, from my experience, everything also always boils down to Ohms law if you drill down enough.
First video I've seen of yours and its great. Very clean, no blurry camera stuff, WELL explained, excellent format of diagrams and bench testing. Liked and Subscribed!
Awesome, thank you!
Great in-depth video on the 555 in astable mode. A follow up video could cover monostable mode. This would explain why the designer of the device didn't just connect trigger and threshold together inside the chip.
Thanks for your comment. I do intend doing some follow up videos to this.
My very next video however is going to be a review of a nifty digital microscope.
Wow! One of the best things on internet in a long time ...! Excellent job. Keep posting
Thank you! Will do!
The first chip I ever played with, because it was useful, and cheap (I miss Maplin) . blew a few up. know it inside out, upside down and backwards. This is a great explanation to the next generation of 555 users.
In my trade, Maplin was a handy local store for whatever construction site we worked on, if you needed something urgent. However, the walk from site to the nearest Maplin soon become known as "The Walk of Shame" because it meant you had not planned your works properly.😆
wow, best explanation of 555 ever. GJ! And great visuals! If people in schools explained things like you do, i just might have finished it xD
Wow, thanks! Great comment.
A good beginning explanation of the 555. Thank you for your time in presenting this lesson. Will follow up with the other lessons you offer. Thanks again! 👍🏻
Glad you enjoyed it!
This is a brilliant explanation of how the 555 can be used and _why_ it functions as it does. I appreciate you showing them in animation as well as on the bench and with the scope. I wish I had this instruction when I was in school.
This all being said, you didnt really dive into your thesis on why this chip "isn't a timer". I'd say that this chip is similar, conceptually, to the escapement mechanism of a clock if used in such a circuit. It can convert an analogue oscillation into a digital count, and even if it can only count to one, isnt that the absolute basis for timing? In any case, the bait worked and I'm here for it, have your engagement, I'll be back for more no doubt 🤣
Thanks for the comment.
Controversial thumbnails jump out at people and grab attention 😄 The main purpose of the video was to demonstrate how the internal building blocks work, in conjunction with the components you install around the chip, to make it into a timer.
excellent explanation of how the 555 works.
Thanks! 👍
Well done. Good graphics, good explanation. Every time I work with a 555, I have to relearn how it works. Now I know where to go for that information.
Thanks 👍
Loved it. Took me back to my teens in the 80s. I never understood it then tho. More like this please
Thanks for the comment. More videos coming....
I designed circuits using 555 timers back in the late 80’s. Thanks for the memories! BTW the 556 is twice the fun 😊
Thanks, glad you enjoyed it.
First time you've shown up in my feed. Your explanations and presentations are so good that I've subscribed!
Brilliant! Thanks for subscribing.
It is worth mentioning that the Control Voltage *pin, #5, is also known as the Pulse Width Modulation pin.* I have had great fun playing with that function, even turning a CMOS 555 into a Digitial Mode audio amplifier with pin 5 as the audio input! A couple of extra components are needed beyond the usual few for a simple timer: an external transistor to make the duty cycle 50% ON and 50% OFF, plus an inductor to knock out the high frequency elements of the output signal, and a small capacitor on pin 5 to give DC isolation from the audio source. I set the oscillation frequency to be 2 MHz, which is only possible with the CMOS 555. That meant each wave of the audio input was _in effect_ 'sampled' 100 times (for 20 kHz audio), and 100,000 times (for 20 Hz audio), giving high fidelity to the *_implicit_** A-to-D conversion* and to the audio output. 🙂
Thanks for sharing your knowledge.
NPN - never points in, PNP - points in is actually brilliant sir. I will remember this forever
Great! Glad it helped.
Very nicely explained 👍 In fact, I rate this video excellent. I found myself watching all the way through even though I already knew how it worked. And have used it in many circuit configurations. Including an opposite polarity one shot monostable pulse generator (to generate a reset pulse for another chip). The number of different circuit configurations shows how flexible it is.
Many thanks for your comment.
I agree this is one of the best explained 555 timers vides that I have seen, I remember looking at the timer at college and it seem difficult to understand as we had was the RS data sheet written by electronic professors
Thanks. Brilliant comment, encourages me to produce more....
I may be wrong, but I thought this was a perfect video. I’ve never given that compliment before, though, to be honest, Veritasium deserves and others deserved it. Great job. No one should ever replicate this video.
Thanks for the comment. Much appreciated.
You put a lot of effort into this video, thanks, I hope you are not discouraged by the lack of interest
Thanks. It was indeed a lot of effort. I just hope people enjoy the results. Thanks again for your comments, much appreciated.
Lack of interest? You commented 3 hours after it was published. Give it time, Im sure this vid will get a lot of views .. or at least it should, considering how good it is.
@@tedbastwock3810 I could not have said it better myself. This is by far the best explanation. I think this video will go viral
People say it wasn't named after the 5K resistors because that's what the inventor of the 555 said in an interview. It was named by a marketing fellow who thought "555" was catchy.
Brilliant video, BTW.
Yes, I have heard that too, but for me it seems too co-incidental.
Thanks for the comment.
Maybe the marketing fellow saw the schema and got the idea.
@@paulpkae You may think it is too coincidental but it don't know any reason to think it is not a simple coincidence. Historically there was no logic for how these early ICs got their number designations. As far as I know it was generally mostly chance. The 556 is essentially two 555s in a single package. There is no difference in the resistor voltage divider. I don't recall hearing anyone speculating where the name came from back in the 70s or early 80s. No one questioned where 7404 got that designation either. Engineers just like to number things.
you are a fantastic teacher! The explanation of the internal workings is brilliant.
Thanks for the comment. Glad you liked it.
i once worked for a small company whose main "electrical engineer" only knew relay ladder logic. I designed a simple 555 circuit operating in a sequence to signal solenoid air valves to open to blow dust from a multiple dust bag system into the waste bin. Worked like a champ. They thought it was the cat's meow.
Brilliant!😄
Although my mind is mush watching this video I actually really understand it the way you explained it at the end. I just stumbled across the video and it seemed interesting especially the way you explain. I love seeing your real world example after your lecture because it lets me see it in action which I need to be able to get an understanding.
Glad it was helpful!
Great description and video!
555 was developed by Signetics founded by some former Fairchild Semiconductor Engineers (like Intel was). I worked at National Semiconductor (just around the corner from the Signetics Plant) and we called it the "Triple Nickel" at least in our department(Test Engineering) when NSC decided to second source the 555. Still have a Signetics Apps Book on my bookshelf and a very useful chip when the only option was a bunch of TTL Logic to do timing when you could get away with only a few external components back in the day.
Thanks for the comment and your interesting history insight.
I've never stuck through with properly learning electronics on this level, but have found reasons to solder and build anyway. This was brilliant. Perhaps I'll end up brushing off one of my kits!
Glad you liked and thanks for the comment.
Really excellent video and description. Thank you!
Thanks, glad you enjoyed.
As a visual learner, this helped me a lot.
Great! Glad it helped.
I love the 555 many applections think out side the box!
In 1980 I used a thermistor in the timing circuit to produce a temperature sensitive pulse duration. That pulsed a milliwatt CW transmitter so I could remotely get temp data by monitoring time between pulses. That got implanted in free ranging woodchucks so we could monitor location and hibernation status.
This is the first IC I grew up learning. It all took off from there, good times. I may relive that. I still have at least 10x 555 and 10x 556 IC.
Great production! This was excellent. Hope you'll do many more this way; I'll be keeping an eye on this channel
Thanks. Yes I have many more planned but I get little free time at the moment. That's set to change. So yes indeed, keep an eye out.
Enjoyed the whole video. I had learned about 555 before but this is much clearer and easier to remember. Keep doing this please. Cheers.
outstanding video. Made the operation of the 555 very easy to understand! Great Job.
👋
Glad you liked it!
This is a fantastic video and explanation of the 555. Thank you so much! 🙂
Glad you enjoyed it!
Very detailed electrical engineering, thanks for all the explanations.
Glad you liked it
I can only agree with the many praising commentators, and say that this is an extraordinarily well thought through and presented video. It "breaks down"the subject into basic parts, functions and concepts, and then explains all of them clearly and succinctly.
As a complete "electronic ignoramus" I do have a couple of questions that would be very greatful if someone with a little more knowledge could answer.:
Firstly: when a "pin goes high" does that mean that it's pulled up to same voltage as "Vcc" ? If not then what voltage ?
Secondly: what if anything happens if you put a voltage on the "control voltage pin" that is less(lower) than ⅔ of "Vcc" ?(meaning that it is lower than the voltage that is supplied by the "voltage divider" to "comparator#2") will it lower the voltage of the"comparator pin" to the "control voltage" by continuously "sinking current" from Vcc ?
Many thanks for this fantastic video "lesson" :)
Best regards
P.s.
If I were to attempt to give any, hopefully constructive, criticism it would only be that the clips where you show your "real circuits" and point to the relevant components and connections possibly could have been benefitted by some "zoomed in shots" of some of the smaller details.
Again many thanks
Hi thanks for your comment and great questions.
1) When the pin goes High, the output is indeed driven to the supply voltage. But, most 555 chips (an other ICs) cannot drive their outputs completely to the supply voltage and in reality will be a slightly lower voltage, especially if you place a sizeable load on the output pin.
2) If the control pin is at a lower voltage than 2/3 supply, then it will be pulled down 'close to' that voltage. But this will be affected by the output impedance of the secondary supply and how well it can sink current. Note the 1/3 voltage leg, going off to comparator 1, is also affected by the control pin voltage.
Nice to hear this explanation lives on..
PNP & NPN Was one of the first things I was taught when I was in a YTS T.V. Engineer training apprentice. ~1986 +
Point iN Please & Not Pointing iN.
Project building hobby led to a self taught knowledge of the voltage polarity workings for basic switch amplification. ie.
PNP = A Positive on the Emitter then the base should be held Negative 0v to switch the collector through to the Positive.
NPN = A Negative on the Emitter then the base should be held Positive to switch the collector through to the Negative.
Basic relay type stuff.
But also a general rule in amplifiers but that gets more datasheet reliant for HFE values etc.
Cheers.
Thanks for the comment.
I learned about the 555 in the late 70s. By then, I had played with the usual configurations (blinking LED, speaker sound, etc). Shortly after, a photographer friend asked me if I could build him a timer for his photography enlarger lamp. He wanted it to be controllable from just a few seconds to well over a minute, with strictly repeatable results. So I had this crazy idea, which I wasn't totally sure that would work: I wired two rotary, 10-position switches and associated potentiometers (trimmers, actually) in series so that the resistances of "high-value" (tens of seconds) trimmers would be added to that of the "low" (seconds) trimmers. And it worked, too. With that arrangement, I could set the switches to any discrete time interval between 0 (lamp on for only as long as the start button was pressed) and 99 seconds. The 555 timer output was routed through a transistor to a 120V relay, which drove the lamp. The photographer friend used this for many years, and I still think it was one of he coolest things I've made as an electronics hobbyist.
Thanks. Sounds like a great little project that has stuck in your mind all these years.
I remember back in the 70's with my father in his ham shack bread boarding a nixie tube light sequencer based around a 555. Thanx for the memory.
Great stuff!
Wauw, even though there are over 300 reactions telling you this is the best explanation ever seen, I'll just add another one. What a great explanation, one of the best 30 minutes on UA-cam :-). Thank you for sharing, I've subscribed!
Great! Thanks for watching, the comment and even more for Subscribing.
What an explanation, would love to see you explain stuff like PID-controls and DC/DC bi-directional converters