This is gonna sound crazy, but this series(DC2DayL) has helped me more than anything/anyone else in the years of reading, research, conceptualizing and trying to teach myself. I can’t explain why, but your concise and logical approach has me finally “understanding”. I hope to find a more direct communication channel in the links/ forums because I’d really like to hear more on the deeper subjects/circuits! This comment has turned into a rant, but I hope you see it and realize just how transformational they have been for me. RoCkOn!🤘🏼🤘🏼
I really, really enjoyed this. Really clear and concise, but you didn't feel like you skipped over anything. There's nothing worse than someone cutting from a very simple idea and then throwing in a bunch of components without explaining what they are for. Personally I'd like to see a lot more on transistors, when to use what kind and how. Maybe even making and / or / nor etc gates with them. Keep up the good work!
@AmRad Podcast That's a good idea. I tend to stick to TTL logic chips when I need something, when I *know* that a lot of the time a transistor would actually work perfectly fine, depending on the need. So it would be good to have a few examples of nice practical uses where I can break the buggers out, rather than say, stuffing a microcontroller into something.
You comment at 7:46 about the 3 LED and resistor series possibly having different voltage drops across each LED (assuming manufacturing tolerances) as a reason for utilizing the transistor circuit and then at 11:34 comment that each of the 4 series LEDs in the transistor circuit will have the same voltage drop. In both circuits the current through the respective LED in series will be the same, so what principle makes a consistent voltage drop on the transistor LED series that is not achievable in the non-transistor series? Not following the logic of a more complicated circuit requiring 2 voltage sources (5V and 12V) to achieve the same result of illuminating the LED. The transistor should have no impact on manufacturing tolerances of the LED, should it?
Could I use this to drive a NUBM08 laser diode at 3A? What are the disadvantages and advantages of this setup compared to a linear regulator (such as using an LM317)?
I'd really like to hear / see the difference between smoothing capacitor and decoupling capacitors. They sort of look the same but there must some difference I don't understand.
Newbie here, still have lots to learn, I really enjoyed this video, thanks so much (I ended up replicating what you did, it was fun) but my multimeter is currently down and I’m curious to know about the volts, the 1.8 volts from the base to the emitter, and the 12 volts -0.7v you supply from the collector-base, would that mean there’s 13 volts being supplied across the emitter collector junction?
Thanks! It hadn't occurred to me to think about the voltage drops along the base-emitter path. Now I also have a better understanding of using an NPN transistor as a switch (emitter connected to ground, and a current limiting resistor between the input signal and the base). The current limiting resistor would have to drop the input voltage minus the base-emitter drop (around 0.7 volts). Thinking of a BJT as a current amplifier, could you also control collector current by limiting the current into the base? For example, 5 volts connected to a 50K resistor to the base, emitter to ground. Current into the base would be 0.1 mA. If the transistor has a beta of 200, the collector current would be 20mA. I'm guessing this is less stable/reliable. I imagine the beta varies between transistors (even in the same manufacturing batch). And does it vary with other factors (like temperature)?
how come you dont have to account for the .20mA for the other LEDs, when you had one led in the circuit it had a draw of 20mA, but when you had 4 it only had 20mA draw as well, im guessing that has to do with it being in series and that current stays the same, but still a little confusing to me.
Can you talk about commercial LED lighting, such as under-cabinet lighting equipped with a dimmer? What is the dimmer doing to the wave-form, how does it accomplish this, and why doesn't it get warm? (While the power supply and lights are getting noticeably warmer during use?)
Usually those are driven via PWM (pulse width modulation.) In PWM, the LEDs are NOT constantly "on", rather they are turned on an off very rapidly with rapid pulses (think square waves.) To us humans, the LEDs look like they are on solid, because of Persistence of Vision. (If you take a camera with a frame rate that is synchronized with the pulse wave, you can see the LEDs turning on and off.) The amount of time the square wave is "high" vs. "low" controls the brightness (known as "duty cycle.") What the dimmer is doing is it is varying the amount of time that the square wave is "high" (LEDs are on) vs "low" (LEDs are off.)
@@chrisallington1638 Nowadays, usually with some sort of microcontroller, like an Arduino. Google "Arduino led pwm" and you will see plenty of examples. You could probably do it with a 555 timer with a variable resistor/capacitor to control the pulse frequency as well. Google "555 timer pwm" and you should see some examples of that.
Can you make a video on transmitters and receiver module circuit diagram used for RC car or toys , reverse engineering. Second thing I'm taking the liberty to ask your help, I'm a beginner in electronics, having basic knowledge, suppose want to design own transmitters and receiver module circuit, for RC toys, what are the topics I should study📚✏
With the prospect of an SHTF given our present and deteriorating economic outlook causing power failures;; I'm wondering how possible it would be to extract enough atmospheric electricity to light enough flashlight LED'S for home elimination and recharge a bank of batteries that would power other household appliances. Or would it be more practicable, all be it more expensive to just use solar panels,
@AmRad Podcast 2 transistors and 2 resistors, and you'll have constant current no matter the voltage (to the rating of the transistor). I think 2N3904 can go up to 40V. A single transistor works if the source voltage doesn't change. Like in a USB power.
You really don't 'want to be' _several volts_ above that required by the LED string. Anything at or above that value is just fine. If all you have is 12 volts, or that voltage is already in your design, it would be a waste to buy or add another supply voltage just for the LEDS, but a good 9 volt supply would have worked just as well.
This is gonna sound crazy, but this series(DC2DayL) has helped me more than anything/anyone else in the years of reading, research, conceptualizing and trying to teach myself. I can’t explain why, but your concise and logical approach has me finally “understanding”. I hope to find a more direct communication channel in the links/ forums because I’d really like to hear more on the deeper subjects/circuits! This comment has turned into a rant, but I hope you see it and realize just how transformational they have been for me. RoCkOn!🤘🏼🤘🏼
I really, really enjoyed this. Really clear and concise, but you didn't feel like you skipped over anything. There's nothing worse than someone cutting from a very simple idea and then throwing in a bunch of components without explaining what they are for.
Personally I'd like to see a lot more on transistors, when to use what kind and how. Maybe even making and / or / nor etc gates with them. Keep up the good work!
@AmRad Podcast That's a good idea. I tend to stick to TTL logic chips when I need something, when I *know* that a lot of the time a transistor would actually work perfectly fine, depending on the need. So it would be good to have a few examples of nice practical uses where I can break the buggers out, rather than say, stuffing a microcontroller into something.
I should have seen this video two-three years back. Very useful👍
You comment at 7:46 about the 3 LED and resistor series possibly having different voltage drops across each LED (assuming manufacturing tolerances) as a reason for utilizing the transistor circuit and then at 11:34 comment that each of the 4 series LEDs in the transistor circuit will have the same voltage drop.
In both circuits the current through the respective LED in series will be the same, so what principle makes a consistent voltage drop on the transistor LED series that is not achievable in the non-transistor series?
Not following the logic of a more complicated circuit requiring 2 voltage sources (5V and 12V) to achieve the same result of illuminating the LED.
The transistor should have no impact on manufacturing tolerances of the LED, should it?
@AmRad Podcast : Thank you for the further details and explanation. I appreciate it. Cheers!
interesting video! i would like to see the more complicated and stable constant current/ led driver circuits..
Loved it 👍
I would love to see some cool projects involving the RGB LED's. Maybe controlling them with an Arduino?
nice to see the basics - thank you. It would be nice to see something about energy harvesting.....
Could I use this to drive a NUBM08 laser diode at 3A? What are the disadvantages and advantages of this setup compared to a linear regulator (such as using an LM317)?
gr8 video!! could you pls help me understand why would 4 digit 7 segment display run on low brightness when multiplexed via arduino?
Maybe the LEDs in the setup aren't recieving enough voltage. Or so i guess
I'd really like to hear / see the difference between smoothing capacitor and decoupling capacitors. They sort of look the same but there must some difference I don't understand.
Newbie here, still have lots to learn, I really enjoyed this video, thanks so much (I ended up replicating what you did, it was fun) but my multimeter is currently down and I’m curious to know about the volts, the 1.8 volts from the base to the emitter, and the 12 volts -0.7v you supply from the collector-base, would that mean there’s 13 volts being supplied across the emitter collector junction?
Hey Derek is there a way I can email you a specific question regarding a project of mine?
Thanks! It hadn't occurred to me to think about the voltage drops along the base-emitter path. Now I also have a better understanding of using an NPN transistor as a switch (emitter connected to ground, and a current limiting resistor between the input signal and the base). The current limiting resistor would have to drop the input voltage minus the base-emitter drop (around 0.7 volts).
Thinking of a BJT as a current amplifier, could you also control collector current by limiting the current into the base? For example, 5 volts connected to a 50K resistor to the base, emitter to ground. Current into the base would be 0.1 mA. If the transistor has a beta of 200, the collector current would be 20mA. I'm guessing this is less stable/reliable. I imagine the beta varies between transistors (even in the same manufacturing batch). And does it vary with other factors (like temperature)?
very nice and interesting video.
sir it would be perfect if you break down a car led headlight bulb driver circuit.
good job
thank you very much sir
Can I drive 16 leds from the same setup just by calculating the resistors? Thanks.
How would I shift an led in the AVR processor?
nice .....sir..😊
helli, would you mind a O10 LED MODULE feature ..
how come you dont have to account for the .20mA for the other LEDs, when you had one led in the circuit it had a draw of 20mA, but when you had 4 it only had 20mA draw as well, im guessing that has to do with it being in series and that current stays the same, but still a little confusing to me.
Can you talk about commercial LED lighting, such as under-cabinet lighting equipped with a dimmer? What is the dimmer doing to the wave-form, how does it accomplish this, and why doesn't it get warm? (While the power supply and lights are getting noticeably warmer during use?)
Usually those are driven via PWM (pulse width modulation.) In PWM, the LEDs are NOT constantly "on", rather they are turned on an off very rapidly with rapid pulses (think square waves.) To us humans, the LEDs look like they are on solid, because of Persistence of Vision. (If you take a camera with a frame rate that is synchronized with the pulse wave, you can see the LEDs turning on and off.) The amount of time the square wave is "high" vs. "low" controls the brightness (known as "duty cycle.") What the dimmer is doing is it is varying the amount of time that the square wave is "high" (LEDs are on) vs "low" (LEDs are off.)
@@Otakunopodcast But, how?
@@chrisallington1638 Nowadays, usually with some sort of microcontroller, like an Arduino. Google "Arduino led pwm" and you will see plenty of examples. You could probably do it with a 555 timer with a variable resistor/capacitor to control the pulse frequency as well. Google "555 timer pwm" and you should see some examples of that.
Can you make a video on transmitters and receiver module circuit diagram used
for RC car or toys , reverse engineering.
Second thing I'm taking the liberty to ask your help, I'm a beginner in electronics, having basic knowledge, suppose want to design own transmitters and receiver module circuit, for RC toys, what are the topics I should study📚✏
With the prospect of an SHTF given our present and deteriorating economic outlook causing power failures;; I'm wondering how possible it would be to extract enough atmospheric electricity to light enough flashlight LED'S for home elimination and recharge a bank of batteries that would power other household appliances. Or would it be more practicable, all be it more expensive to just use solar panels,
Excellent video to start messing up with LEDs.
This is why they have 2 transistor current mirror circuits.
@AmRad Podcast 2 transistors and 2 resistors, and you'll have constant current no matter the voltage (to the rating of the transistor). I think 2N3904 can go up to 40V.
A single transistor works if the source voltage doesn't change. Like in a USB power.
Dark corners? Hummmm. 😉😎
So you change your name from currectsource, then talk about currentsource? ;)
You really don't 'want to be' _several volts_ above that required by the LED string. Anything at or above that value is just fine. If all you have is 12 volts, or that voltage is already in your design, it would be a waste to buy or add another supply voltage just for the LEDS, but a good 9 volt supply would have worked just as well.