I built a similar circuit when I was 17 and housed it in one of those large oven matchstick boxes wrapped in black tape. Then I decided it would look really cool as an alarm deterent in my Ford Fiesta. So I put it in there and when I locked the car it would swish back and forth in a dazzling display to warn off potential thieves and toe-rags. My Fiesta was broken into the next night and my SONY tape deck was stolen. The knight rider light probably drew too much attention to my car! Funny thing is, they left the knight rider light in there and it was still happily blinking away the next morning, underneath the guts of wires which had spilled out in the absense of my car stereo. I guess the thieves were not as impressed with my creation as I had been, as apparently it wasn't even good enough to nick.
That brings back memories. When I started with Atmel processors I did that as my first project. Just making the light run back and forth was not enough, I added a couple of brightness levels (with pwm), a button to select more patterns and a serial interface to download even more patterns with a processor without support for serial interface (I hate doing serial interface in software, but often have to do it). It was a 2313 processor and I had to share pins for the select button and serial interface. After that I decided that I had learned the basic about how to program a Atmel processor.
There are still simple Knight-Rider electronic kits on the market that have 10 Outputs. You can reduce the amount of outputs when connecting the Reset Input on the next output that you don't need. For example: If you want to use only 7 Outputs, then you have to connect the Reset-pin to the 8th output. Such a Kight Rider circuit use an Oscillator build of a NAND CMOS Chip, an up/down BCD counter and a BCD to decimal decoder with 10 decoded outputs. These Outputs are connected to 10 transistors to drive 12V Halogen Bulbs or something else.
Well... technically its always been called the knight rider scanner, but recently evil mad scientist coined the term larson scanner. Im not saying that you cant call it that, but you should understand that its a new name.
Glen A. Larson was a hack who stole script plots from other shows and called them his original works. He did this so often that he acquired the nickname "Glen Larceny." He was also notoriously cheap! "His" bouncing back and forth scanner lighting effect was used in three different television series: Battlestar Galactica, Knight Rider and Buck Rogers. I guess that he was also in control of the props departments' budget as well. However, my favorite Larson story is the one about how Jim Garner (from "The Rockford Files" show) punched Larson so hard that Larson he flew across the curb, into a motorhome, and out the other side! I guess he deserved it. [ref: en.wikipedia.org/wiki/Glen_A._Larson#Criticism ] Bottom line... let's all not call this LED chaser circuit a "Larson Scanner" anymore. KC
I’m sloooowly gathering dip ICs for such times. And well pretty much anything to run them. Basically I’m Starting New after the loss of my twin. Love your work, Nice walking around this subject. Thank you.
I think you could have used a matrix of diodes and a single resistor to ground. This would have avoided the potential divider effect and given a common resistor to set the led current. The diodes turn the 4017 outputs into a source only.
I dont think you have to use so many resistors, why not just 1 on the ground side, these chips can handle signal crossing from pin to pin. So no worries. And add capacitor for each LED for the fading effect.
You did create a voltage divider, and the blue LEDs were at best marginal. If the voltage divider were perfect, then the midpoint would have a voltage of 2.5V, insufficient to trigger the LED. However, at that point you're also trying to sink a full 25mA into the "off" output of your poor 4017! From the respective datasheet, at Vdd=5V the output pins seem to be able to sink only 1mA. If you used your scope, I suspect you'd find that the chip's output to be quite a bit higher than 0V.
When I want to know the polarity of LEDs, rather than looking at the flat side I look at the metal inside the plastic. One of the two pieces has a support for the die and is shaped like a seven. That one is the cathode (negative). I imagine it like a little minus sign with the lead hanging off the end.
Same here. I've been using an HP LJ1200 since early 2000, and it has cost me just under £100 so far in toner to print at least 13,000 A4 sheets. It's still working perfectly. My wife has an HP colour laser printer, bought at cut price from the Bay of Itchy Things. It's just onto its second set of toner cartridges after about 9 years of use, and still printing like new. When we had inkjets, £35 for about 50 pages of good colour prints was simply ridiculous. The laser colour prints are costing less than 4p per page, including the paper price. Oh and neither printer suddenly runs out of toner. The '1200 can print at least 800 more sheets after the first hint of low toner levels; a situation which can be alleviated by agitation of the cartridge to give a few hundred more pages of good prints.
Laser printers are for those who print a lot. We don't print almost anything, so we use an HP Officejet Pro 8620 that works flawlessly and the ink is very cheap. About 1.5 cents per page!
I know this is a couple of years old now but it seems to me that using all those resistors from the ic's output pins would mean confliction! Why not use small signal diodes (1N4148) at the points where you are doubling up and place a single resistor from the LED cathodes to ground.
I made the elektor's circuit only with leds without the 12v car bulbs somewhere around the '80s but as i remember it was way too complex using binary counter,up/down latch flip flop and a binary to decimal chip.The price of 4000 chip series was expensive enough and the sellers warped the chips in aluminum foils to prevent electrostatic damage.The circuit is the easiest it could be.Very nice.
wow wow wow... hold yer horses auld boy. British he may be... but not all British people are English! Some of us are Scottish. Myself being Scottish would have bought an Arduino and some 595 shift registers.
Back in the day I made one with 74LS TTL and the 10 LED bar modules. I forget what chip the decoder was but it used all 10 of the LEDs. Plus the 555 timer of course. Had lots of fun with it.
You probably dont care but if you are bored like me during the covid times you can watch pretty much all the latest movies on InstaFlixxer. Have been binge watching with my brother for the last couple of months xD
Sun workstations (and servers) used to have a line of leds display informally known as the cylon-eye on the back... as the load went up the 'eye' went slower.
Mine didn't work at 5V - upped it to 9V and 220 R's and works fine. Got lost with your explanation so I just built a chaser and reversed the order after 6th led. Didn't think it would work with 2 R's on the middle 4 but it does - I guess the second R blocks the current from feeding back into the chip and forces it through the led. Good trick, thanks.
There was series one and 2 with single screen, and dual front fog lights, series 3 and 4 with dual screens and triple front fog lights. Today, think how much lighter it would have been not carrying those heavy components.
The non-end ones are dimmer because they're on a voltage divider between a pin with the one that's high with the one that's low. Either use a 200 ohm resistor or permanently tie a 100 ohm to ground across the end LEDs.
Very Nice Julian. Like the way you used resistors on the back flash sequence for a simpler circuit. Brings back memories when the Knight Rider shows was on, I did as you, building the circuit with a 555 and 4017, with the difference, I used 1N914 diodes as 'steering diodes' to do the reverse sequence. And yes, there were no bright power LED's then, but 12V incandescent bulbs so the output went to a bank of TIP31 NPN transistors (if I remember correctly) to the bulbs, which did leave the tailing effect where the bulbs faded as each one switched off. I still have that unit stored away in a truck somewhere and after seeing your video, I might dig it out and play with it again. Of course, to upgrade to 1 or so watt LED's, to get the trailing effect, I would likely have to add some electrolytic caps on the base of each power transistor to get the same effect as the bulbs did. Thanks for the video, it sure brought back some memories.
would it work if you connect the lines of the middle LEDs before the resistances? (so instead of output6->resistor +output4->resistor you would do output6+output4->resistor)
I bet someone has already said somewhere in the comments that the circuit design is quite bad. He should have used diodes to connect to the diodes anode and put the resistor between cathode and ground. This way all leds have the same voltage and current and you don't have a voltage divider on most pins just to create heat.
I just watched a video at RSD Academy on using an op-amp voltage follower to fix this issue with feeding a low impedance load with a voltage divider. It made sense, but the aha moment just came when I saw the same "issue" being used to drive the LEDs here. The LED (load) and the resistor to ground are in parallel so voltage divider is the 100 ohm from power and slightly less than the impedance of the LED to ground. Very nice basics lesson tucked into a circuit building video.
you need to add diodes on leds 2 -5, you are back feeding voltage to the IC when you go up and come back down. you will burn out the IC eventually if you dont add the diodes.
As an adult looking at your box of resistors, it gives me the same thrill as looking at a box of firecrackers when I was 13. Although now, I don't want them to smoke and blow up.
82Pontiac trans am and was call K.I.T.T The lights on the car had more than one light on at a time creating a chase when leading light was getting brighter the mid-light was full power and last light fading think it had 8lights
I got sick of inexpensive inkjet printers getting clogged up during periods of inactivity. So I got an inexpensive brother laser printer. Pretty happy.
It is illegal to have a blue light on cars in the US. You can get slapped with an impersonation charge. Impersonating a police officer is a felony here.
I think Epson has a problem with ink drying if not used because my 1st one blocked and I never got it cleaned out even passing warm soapy water through it. My Epson was one of the early ones, but that was enough of Epson for me because my older Canon inkjet never had problems. In the end I went mono laser Canon because it's faster and less problems.
Really need a microcontroller to to Knight Rider (or Cylon eyes) properly, because the LEDs should be hard on then fade out so there's a bit of a comet trail effect. I've implemented this effect several times, microcontroller does the best at replicating the original effects.
Hi Julian, I couldn't get the shared output LEDs to work without adding a diode for each output on the 4017 (minus the two end LEDs of course). Every time I tried it without the diodes the alternate output would pull the other down to ground. Could it be a difference in the 4017 I'm using? I've had it for years (at least 15 years, possibly more) I think it came out of an old Radio Shack Electronic Experimenters Kit.
Misha, I ran into the same issue. I proved to myself that the "off" output pins are actually pulled to ground by flipping all the LEDs so they would have common positive instead of common negative and I end up with an alternate universe scanner (all leds are on except one that animates). There must be some variations on 4017 that Julian's off are open circuit whereas ours are grounding. :-(
I ended up pulling all the resistors but one (moved it to the common cathode side) and adding a 1n4148 diode to each LED that shares an output from the chip (8 in total). The first and last LED are run directly to their respective output pins on the chip. It does the job. :-) Here is a link to a short video showing it working ua-cam.com/video/oJMCOauRevQ/v-deo.html.
You could have kept the potential divider for the end LEDs, just by adding two more resistors, between the anodes of the end LEDs and ground. This would have given the divider, where one "output" was always grounded, giving effectively the same circuit to those LEDs as the ones in the middle. :)
"Positrons" and "Negatrons", Eh? I like "Pixies" myself. LMAO Sometimes the Pixies get a little angry. lol Great video. I've ordered some 4017's and binary counters. I think I'll be trying to make an 8 bit computer as well. It seems great fun. I've also just built a 555 LED dimmer on breadboard with a 7805 regulator and N-Channel MOSFET inspired by Adam Welch's video. Maybe I should tear it down and walk through the setup. Hmmm, decisions, decisions.
Ive been messing with this kind of circuits lately. There are many decade counters similar to the 4017, but with different features. The whole 4000 series chips are very interesting. This circuit was originally used by glen larson on 2 tv shows, knight rider, and battlestar galactica (cylon helments). I would like to see the original schematic used in glens design. Im pretty sure he has caps on each LED to make the LEDs fade. For even more fun, try these circuits on 7 segments or other LED displays.
Probably incandescents as others have said - I don't think LEDs available in that era would have been bright enough to show up on film properly... plus you get the nice fade up / fade down for free. you could get small bright incandescents back in the day... e.g. ua-cam.com/video/Vkfpi2H8tOE/v-deo.htmlm49s
I remember how crappy the LEDs were back then, and I dont remember seeing any that were that big, but my guess is that they were LEDs on both the cylons and the car.
Maybe you have a special 555 because my LED does not flash at all with a tantalum cap. You have to keep switching it on and off to get it to flash every time you connect.
i used 2 of the 74154 in a circuit get a 32 LED chaser that is reversible making it a large scanner :). i made this circuit years ago in school to prove a teacher WRONG i was so proud of it and it still works today.
I have had issues getting the 555 timer portion of the circuit to work, I was sure I followed your method exactly - however i'm not sure why it is not working. The LED does not flash, it is on constantly, until you turn the pot so far then the LED goes out. Does anyone have a link to a circuit diagram?
Nicely done. The 'trailing' effect is quite difficult to do with LEDs (easy with a microcontroller), but it appears here due to the camera's persistence. I suspect you're correct about the original being incandescent. Fun.
The original used bulbs with filaments. There were separators between each bulb space to prevent too much bleed but enough to let a very small amount of light through. That faded trailing effect is easier to do with bulbs and the small gap helped the effect.
Was the effect achieved by using a motor-driven rotary switch for the incandescent lamps? That would have been simple, low-cost and reliable, in its day.
Your first thought about the potential divider is perfectly correct. If the blue LED really required 3.5V then it would not light. It looks like you're using a 6V supply so the Thevenin equivalent of your divider is a voltage source of 3V with a source resistance of 50 Ohms If you draw that load line on a V-I curve for a blue LED ( like this one lednique.com/wp/wp-content/uploads/2016/09/IV-curves-all-colours.png ) It goes from 3V to 60mA and intersects the blue diode curve at about 13mA which is plenty of current for a blue LED.
That's an interesting approach Julian. The original effect though has fade up and fade down in the sequence so that three or so segments are lit at varying intensities. I managed to get an Arduino to do this on the PCM outputs which I was very pleased with. I enjoyed the video anyway as always.
HI MATE can this be done with 17 leds? noob here my leds have resistors already on i have 4017 and 555 is it possible for a noob diagram on how to do? many thx
golned rule of electronics #1: When working with *ANY* electric/electronic device, *ALWAYS* disconnect the power before doing antyhing. Trust me, i fried few chips because of that.
Because some LED's are connected to more than one pin, if you didn't have the resistors where they currently are, then you would end up shorting out two 4017 outputs which would be at High and Low
Add another resistor anode to gnd on 0 and 6? I made something like this for a 'US style' traffic light. I used one resistor on the common cathode and small switching diodes on the anodes. I still have quite a stock of those diodes. Isn't there a way to make the decade counter run backwards? I know, I could check. But I'm playing with cheap solar pathway lights now. ;-)
Your power supply supples positrons and negatrons? They must annihilate each other inside the 555. Was it getting red hot and emitting loads of harmful radiation?
You could find them by searching for bus wire. I bought mine at Jameco, but even Amazon sells them. They come in all kinds of length and sizes, so make sure you get the desired gauge for breadboard (usually 22AWG). A "free" supply of short jumper wires are cut off remnants from LED cubes. They're pretty much uniform in size, enough to jump up to three breadboard holes. :-)
Nice video! :-) brings back some memories. I remember building that circuit in a long time ago not exactly like yours but in the same principle it might have been same circuit cuz it was a long time ago. :-) but still great job anyways.. to reminisce:-)
Where did you find the original parts? The LED boards and controller? I couldn't find on eBay or Banggood. Can you give us a link? (Also, why not just use a single 200R on a common link to ground?)
Very funny to hear an electronics guy talk about cars. Even funnier that you're across the pond talking about American cars. I can't remember the last time I heard anyone say "Chevrolet". As the world has come to expect, lazy Americans dropped it to barely two syllables. "Chevy" is pretty much the standard. Just started watching your channel, like the work. Feel free to ask me any car question ;)
For hot circuit, or main venue to monitor? Numbers, or castiron see, I'm not coulomb nor sir Thomas. Negation? Reason local of eye in conjuncture w pergatous plates. Positron
Why not? A capacitor in parallel to the LED should charge up to the LED's forward voltage, and then discharge through the LED over time once the power from the IO pin is gone (since the capacitor would never go above the forward voltage, it wouldn't kill the LED). The IO pin should be open drain though, otherwise you'd inject current into the IC, which you don't want. It could still work, though.
I built a similar circuit when I was 17 and housed it in one of those large oven matchstick boxes wrapped in black tape.
Then I decided it would look really cool as an alarm deterent in my Ford Fiesta. So I put it in there and when I locked the car it would swish back and forth in a dazzling display to warn off potential thieves and toe-rags.
My Fiesta was broken into the next night and my SONY tape deck was stolen.
The knight rider light probably drew too much attention to my car!
Funny thing is, they left the knight rider light in there and it was still happily blinking away the next morning, underneath the guts of wires which had spilled out in the absense of my car stereo. I guess the thieves were not as impressed with my creation as I had been, as apparently it wasn't even good enough to nick.
That is both a terribly sad and yet amusing tale. I am sorry for you my friend.
I made this circuit many years ago, my version included caps between the led which gave it a nice trail / fade!
Martin yeah, just wanted to say that
Martin do you happen to remember the value of those capacitors, or can you give a pointer to where i can find out?
I've just been through all my old photocopied circuits .... can't find it anywhere! - let me see if i can actually find the board itself!
Martin
Wow, i didn't expect you to go to so much trouble just for a random stranger.
You, Sir, are a Gentleman of the Old School. :D
Hmmm..... I'm gonna make a guess and say it was 100uF.
That brings back memories. When I started with Atmel processors I did that as my first project. Just making the light run back and forth was not enough, I added a couple of brightness levels (with pwm), a button to select more patterns and a serial interface to download even more patterns with a processor without support for serial interface (I hate doing serial interface in software, but often have to do it). It was a 2313 processor and I had to share pins for the select button and serial interface.
After that I decided that I had learned the basic about how to program a Atmel processor.
my frist arduino thing was just this.
There are still simple Knight-Rider electronic kits on the market that have 10 Outputs. You can reduce the amount of outputs when connecting the Reset Input on the next output that you don't need. For example: If you want to use only 7 Outputs, then you have to connect the Reset-pin to the 8th output.
Such a Kight Rider circuit use an Oscillator build of a NAND CMOS Chip, an up/down BCD counter and a BCD to decimal decoder with 10 decoded outputs. These Outputs are connected to 10 transistors to drive 12V Halogen Bulbs or something else.
It's called a Larson scanner after Glen A. Larson.
Yes its the same scanner in the Cylons in Battlestar Galactica.
Yes, the very same.
Well... technically its always been called the knight rider scanner, but recently evil mad scientist coined the term larson scanner. Im not saying that you cant call it that, but you should understand that its a new name.
Glen A. Larson was a hack who stole script plots from other shows and called them his original works. He did this so often that he acquired the nickname "Glen Larceny." He was also notoriously cheap! "His" bouncing back and forth scanner lighting effect was used in three different television series: Battlestar Galactica, Knight Rider and Buck Rogers. I guess that he was also in control of the props departments' budget as well. However, my favorite Larson story is the one about how Jim Garner (from "The Rockford Files" show) punched Larson so hard that Larson he flew across the curb, into a motorhome, and out the other side! I guess he deserved it. [ref: en.wikipedia.org/wiki/Glen_A._Larson#Criticism ]
Bottom line... let's all not call this LED chaser circuit a "Larson Scanner" anymore.
KC
I’m sloooowly gathering dip ICs for such times. And well pretty much anything to run them.
Basically I’m Starting New after the loss of my twin. Love your work, Nice walking around this subject. Thank you.
I think you could have used a matrix of diodes and a single resistor to ground. This would have avoided the potential divider effect and given a common resistor to set the led current. The diodes turn the 4017 outputs into a source only.
I dont think you have to use so many resistors, why not just 1 on the ground side, these chips can handle signal crossing from pin to pin. So no worries. And add capacitor for each LED for the fading effect.
TheNeurall
You don't even need to use the one resistor, since the 4017 is inherently current-limiting.
You did create a voltage divider, and the blue LEDs were at best marginal. If the voltage divider were perfect, then the midpoint would have a voltage of 2.5V, insufficient to trigger the LED. However, at that point you're also trying to sink a full 25mA into the "off" output of your poor 4017!
From the respective datasheet, at Vdd=5V the output pins seem to be able to sink only 1mA. If you used your scope, I suspect you'd find that the chip's output to be quite a bit higher than 0V.
When I want to know the polarity of LEDs, rather than looking at the flat side I look at the metal inside the plastic. One of the two pieces has a support for the die and is shaped like a seven. That one is the cathode (negative). I imagine it like a little minus sign with the lead hanging off the end.
Really? I've been doing it that way for decades and have yet to see it. Just to clarify: you're saying that sometimes the bond wire is the cathode?
I'll never buy another inkjet, laser all the way baby.
I can confidently leave my mono laser printer sitting for 5 years and it still works flawlessly
Same here. I've been using an HP LJ1200 since early 2000, and it has cost me just under £100 so far in toner to print at least 13,000 A4 sheets. It's still working perfectly.
My wife has an HP colour laser printer, bought at cut price from the Bay of Itchy Things. It's just onto its second set of toner cartridges after about 9 years of use, and still printing like new.
When we had inkjets, £35 for about 50 pages of good colour prints was simply ridiculous. The laser colour prints are costing less than 4p per page, including the paper price.
Oh and neither printer suddenly runs out of toner. The '1200 can print at least 800 more sheets after the first hint of low toner levels; a situation which can be alleviated by agitation of the cartridge to give a few hundred more pages of good prints.
Laser printers are for those who print a lot. We don't print almost anything, so we use an HP Officejet Pro 8620 that works flawlessly and the ink is very cheap. About 1.5 cents per page!
I know this is a couple of years old now but it seems to me that using all those resistors from the ic's output pins would mean confliction! Why not use small signal diodes (1N4148) at the points where you are doubling up and place a single resistor from the LED cathodes to ground.
First flashing led, took me back to Radionic 70 kit I got for Christmas late 70s! Had the potentiometer and ic to get the variable flash rate.
I made the elektor's circuit only with leds without the 12v car bulbs somewhere around the '80s but as i remember it was way too complex using binary counter,up/down latch flip flop and a binary to decimal chip.The price of 4000 chip series was expensive enough and the sellers warped the chips in aluminum foils to prevent electrostatic damage.The circuit is the easiest it could be.Very nice.
The difference between British and North American.... "Focus, please!" vs. "Focus, you fak!"
tiger12506 ave much?
Indeed.
wow wow wow... hold yer horses auld boy. British he may be... but not all British people are English! Some of us are Scottish. Myself being Scottish would have bought an Arduino and some 595 shift registers.
I'd love to hear someone say ARRduinoo in a thick Scottish accent ahah
Isn't AVE Canadian??
Julian Ilett you surprise me.
Why are you using resistors? Wouldn't diodes be better, *AND* result in lower power consumption?
Back in the day I made one with 74LS TTL and the 10 LED bar modules. I forget what chip the decoder was but it used all 10 of the LEDs. Plus the 555 timer of course. Had lots of fun with it.
i hate bipolar 555's , they're awesome
You probably dont care but if you are bored like me during the covid times you can watch pretty much all the latest movies on InstaFlixxer. Have been binge watching with my brother for the last couple of months xD
@Legend Jimmy Definitely, I've been watching on InstaFlixxer for since december myself :)
@Legend Jimmy Yup, I have been using InstaFlixxer for since november myself =)
@Legend Jimmy Yup, I've been using instaflixxer for since november myself :D
Knight Rider.. yes.. I remember. But also the cylons from the old series Battlestar Galatica. ;-)
Sun workstations (and servers) used to have a line of leds display informally known as the cylon-eye on the back... as the load went up the 'eye' went slower.
joinedupjon
DPT (and newer Adaptec) RAID cards did the same thing on idle, and the LEDs were actually PWM controlled so they nicely faded out.
That's where Glen A. LArson took it from as it was and is a good effect.
Mine didn't work at 5V - upped it to 9V and 220 R's and works fine. Got lost with your explanation so I just built a chaser and reversed the order after 6th led. Didn't think it would work with 2 R's on the middle 4 but it does - I guess the second R blocks the current from feeding back into the chip and forces it through the led. Good trick, thanks.
KITT was a Pontiac Trans-AM
It was a slightly body modified Trans-Am wasn't it?
Tony Ling and there were quite a few of them.
There was series one and 2 with single screen, and dual front fog lights, series 3 and 4 with dual screens and triple front fog lights. Today, think how much lighter it would have been not carrying those heavy components.
I prefer KARR!
It is a shit car. I saw it. It is about 3 inches tall. It was clearly designed for American Pygmies.
The non-end ones are dimmer because they're on a voltage divider between a pin with the one that's high with the one that's low. Either use a 200 ohm resistor or permanently tie a 100 ohm to ground across the end LEDs.
We want to see you going down the road with this on your electric bike. While whistling the theme tune to Knight Rider.
Very Nice Julian. Like the way you used resistors on the back flash sequence for a simpler circuit. Brings back memories when the Knight Rider shows was on, I did as you, building the circuit with a 555 and 4017, with the difference, I used 1N914 diodes as 'steering diodes' to do the reverse sequence. And yes, there were no bright power LED's then, but 12V incandescent bulbs so the output went to a bank of TIP31 NPN transistors (if I remember correctly) to the bulbs, which did leave the tailing effect where the bulbs faded as each one switched off. I still have that unit stored away in a truck somewhere and after seeing your video, I might dig it out and play with it again. Of course, to upgrade to 1 or so watt LED's, to get the trailing effect, I would likely have to add some electrolytic caps on the base of each power transistor to get the same effect as the bulbs did. Thanks for the video, it sure brought back some memories.
would it work if you connect the lines of the middle LEDs before the resistances? (so instead of output6->resistor +output4->resistor you would do output6+output4->resistor)
I bet someone has already said somewhere in the comments that the circuit design is quite bad. He should have used diodes to connect to the diodes anode and put the resistor between cathode and ground. This way all leds have the same voltage and current and you don't have a voltage divider on most pins just to create heat.
old version was a Pontiac Firebird. New version Ford Shelby Mustang
I prefer the Vauxhall Victor
Is that some sort of record player, wait my suspicions are correct you also Techmoan. ;)
Also for someone bilingual, is referring to a Vauxhall Victor in the UK like saying AMC Pacer in the US?
AMC Pacer - is that a chocolate bar?
Yes I understand the confusion our version has nuts and yes I have no idea where this conversation is going.
I just watched a video at RSD Academy on using an op-amp voltage follower to fix this issue with feeding a low impedance load with a voltage divider. It made sense, but the aha moment just came when I saw the same "issue" being used to drive the LEDs here. The LED (load) and the resistor to ground are in parallel so voltage divider is the 100 ohm from power and slightly less than the impedance of the LED to ground.
Very nice basics lesson tucked into a circuit building video.
you need to add diodes on leds 2 -5, you are back feeding voltage to the IC when you go up and come back down. you will burn out the IC eventually if you dont add the diodes.
As an adult looking at your box of resistors, it gives me the same thrill as looking at a box of firecrackers when I was 13.
Although now, I don't want them to smoke and blow up.
the negratrons combine with the positrons and produce a black hole inside 555, it's gravity slows time, that's how it works
Did you have a beer or 2 before this ? :D
I'm just in a good mood - it's a bit warmer today :)
I think he's been watching Ave and Clive
82Pontiac trans am and was call K.I.T.T The lights on the car had more than one light on at a time creating a chase when leading light was getting brighter the mid-light was full power and last light fading think it had 8lights
I got sick of inexpensive inkjet printers getting clogged up during periods of inactivity. So I got an inexpensive brother laser printer. Pretty happy.
you probably dont have the Knight Rider Bar, but be cool to see you hook up your circuit to the bar!
What an adorable circuit! 100K Pot, 100 ohm Resistors, 100 points for Julian! :-)
OMG, we love Alicia Vikander so much. Love her acting and she is totally beautiful.
Now you only need to make a board to do the knight rider music using a SN76489.
Not because I have 18 of those hanging about or anything.
It is illegal to have a blue light on cars in the US. You can get slapped with an impersonation charge. Impersonating a police officer is a felony here.
Can you build a Knight Rider Scanner circuit using 2 of the 4017 chips interconnected to each other to operate 8 L.E.D.'s?
My 1965 Imperial LeBaron was another thirsty beast. With a lead foot, you could drop below 8mpg. Memories...
I think Epson has a problem with ink drying if not used because my 1st one blocked and I never got it cleaned out even passing warm soapy water through it. My Epson was one of the early ones, but that was enough of Epson for me because my older Canon inkjet never had problems. In the end I went mono laser Canon because it's faster and less problems.
Really need a microcontroller to to Knight Rider (or Cylon eyes) properly, because the LEDs should be hard on then fade out so there's a bit of a comet trail effect. I've implemented this effect several times, microcontroller does the best at replicating the original effects.
Hi Julian, I couldn't get the shared output LEDs to work without adding a diode for each output on the 4017 (minus the two end LEDs of course). Every time I tried it without the diodes the alternate output would pull the other down to ground. Could it be a difference in the 4017 I'm using? I've had it for years (at least 15 years, possibly more) I think it came out of an old Radio Shack Electronic Experimenters Kit.
Misha, I ran into the same issue. I proved to myself that the "off" output pins are actually pulled to ground by flipping all the LEDs so they would have common positive instead of common negative and I end up with an alternate universe scanner (all leds are on except one that animates). There must be some variations on 4017 that Julian's off are open circuit whereas ours are grounding. :-(
I ended up pulling all the resistors but one (moved it to the common cathode side) and adding a 1n4148 diode to each LED that shares an output from the chip (8 in total). The first and last LED are run directly to their respective output pins on the chip. It does the job. :-) Here is a link to a short video showing it working ua-cam.com/video/oJMCOauRevQ/v-deo.html.
That looks like the design used in the 200in1 electronic workbench kit but the workbench only ran one direction.
You could have kept the potential divider for the end LEDs, just by adding two more resistors, between the anodes of the end LEDs and ground. This would have given the divider, where one "output" was always grounded, giving effectively the same circuit to those LEDs as the ones in the middle. :)
Ok. I finally got it to work. Using 10 diodes and 1 resistor.
"Positrons" and "Negatrons", Eh? I like "Pixies" myself. LMAO Sometimes the Pixies get a little angry. lol Great video. I've ordered some 4017's and binary counters. I think I'll be trying to make an 8 bit computer as well. It seems great fun. I've also just built a 555 LED dimmer on breadboard with a 7805 regulator and N-Channel MOSFET inspired by Adam Welch's video. Maybe I should tear it down and walk through the setup. Hmmm, decisions, decisions.
Do you have a playlist for your 8 bit computer? I’m very interested in it.
Ive been messing with this kind of circuits lately. There are many decade counters similar to the 4017, but with different features. The whole 4000 series chips are very interesting. This circuit was originally used by glen larson on 2 tv shows, knight rider, and battlestar galactica (cylon helments).
I would like to see the original schematic used in glens design. Im pretty sure he has caps on each LED to make the LEDs fade.
For even more fun, try these circuits on 7 segments or other LED displays.
Probably incandescents as others have said - I don't think LEDs available in that era would have been bright enough to show up on film properly... plus you get the nice fade up / fade down for free.
you could get small bright incandescents back in the day... e.g. ua-cam.com/video/Vkfpi2H8tOE/v-deo.htmlm49s
I remember how crappy the LEDs were back then, and I dont remember seeing any that were that big, but my guess is that they were LEDs on both the cylons and the car.
cylon-knight.com/helmet.htm
according to this page, they were bulbs, not LEDs. They ran 16.8v for the bulbs.
Great video! Where do you get the plastic box’s from?
The ultimate goal for all teenagers/young adults is to have a cool car, no matter the cost.
What's the ultimate goal for a 57 year old?
I can't speak for 57 year olds, but maybe a big Mercedes? Or some other sloshy luxury car.
Julian Ilett isn’t it supposed to be a Porsche, a Harley and a 21-year old girlfriend? (I failed on all 3)
The ultimate goal of a 57 year old is to live long enough to draw a state pension.
Maybe you have a special 555 because my LED does not flash at all with a tantalum cap. You have to keep switching it on and off to get it to flash every time you connect.
If it happens again, you could try running a dedicated ink flush through to clean the heads
Try removing chips from sockets with a needle nose pliers.
74154 is also a good variation of this circuit, but needs BCD counter
i used 2 of the 74154 in a circuit get a 32 LED chaser that is reversible making it a large scanner :). i made this circuit years ago in school to prove a teacher WRONG i was so proud of it and it still works today.
Lamps on the KnightRider car were infact Halogen bulbs
I have had issues getting the 555 timer portion of the circuit to work, I was sure I followed your method exactly - however i'm not sure why it is not working. The LED does not flash, it is on constantly, until you turn the pot so far then the LED goes out. Does anyone have a link to a circuit diagram?
Maybe it's flashing very quickly - try a bigger capacitor :)
"Some people" ? A new contention I had no idea about. Why do I miss these memos?
Nicely done. The 'trailing' effect is quite difficult to do with LEDs (easy with a microcontroller), but it appears here due to the camera's persistence. I suspect you're correct about the original being incandescent. Fun.
I would imagine that the original had a ripple counter running through RC networks with bipolar drivers into an incandescent array
The original used bulbs with filaments. There were separators between each bulb space to prevent too much bleed but enough to let a very small amount of light through. That faded trailing effect is easier to do with bulbs and the small gap helped the effect.
Was the effect achieved by using a motor-driven rotary switch for the incandescent lamps? That would have been simple, low-cost and reliable, in its day.
The led only flashes on pin 14 and not the others.
Your first thought about the potential divider is perfectly correct. If the blue LED really required 3.5V then it would not light. It looks like you're using a 6V supply so the Thevenin equivalent of your divider is a voltage source of 3V with a source resistance of 50 Ohms If you draw that load line on a V-I curve for a blue LED ( like this one lednique.com/wp/wp-content/uploads/2016/09/IV-curves-all-colours.png ) It goes from 3V to 60mA and intersects the blue diode curve at about 13mA which is plenty of current for a blue LED.
That's an interesting approach Julian.
The original effect though has fade up and fade down in the sequence so that three or so segments are lit at varying intensities.
I managed to get an Arduino to do this on the PCM outputs which I was very pleased with.
I enjoyed the video anyway as always.
I would love to see your code have you put it any ware pls
I've upgraded my PC recently Andy, but hopefully I can find it in a backup archive, I'd be very happy to share
thanks I think a lot of people would like to see it good hunting !
You had to use diodes for having OR-gates when connecting 4017 outputs together
I used diodes plus a resistor to be like same as those resistor array. I must have done it way back in the 80's
i used diodes on my version..33ish years ago 😲 i still have it 😁
HI MATE can this be done with 17 leds? noob here my leds have resistors already on i have 4017 and 555
is it possible for a noob diagram on how to do? many thx
Always fun Julian. Thx.
Nice video so thumbs up for that :)
But the Knight Rider Lights fade as they move, PWM would be great for that.
I always thought the trail was part of the program. Most Larson Scanner kits include programming for the trail.
Hmm... couldn't you break off with wires first and then run the output of 2 pins through a single resistor? (Ideally reducing the resistor count).
golned rule of electronics #1:
When working with *ANY* electric/electronic device, *ALWAYS* disconnect the power before doing antyhing. Trust me, i fried few chips because of that.
That’s a nice bread board project.
I bet that '74 Camaro would bring you a pretty penny now. I've had two. A 1970 and a 1980. Wish I could've hung onto both.
1: I think in the early part of this video you were on speed :)
2: I can’t believe you had a Camaro!!
3: I love knight rider!!!!!
Great video 👏
Your LEDs are all lit one at a time. I would have just used 1 resistor on the cathode side and gone straight from 4017 to the LEDs
Because some LED's are connected to more than one pin, if you didn't have the resistors where they currently are, then you would end up shorting out two 4017 outputs which would be at High and Low
Then you would have blown up your 4017 by shorting together two of its outputs.
i was about writing the same....;)
Actually the 4017 pull it's output pin high and low therefor you end up shorting the IC diode are normally use for this purpose.
Moker yes.
84 Pontiac Trans Am. Same frame as the Chevy Camera ( I believe)
The same frame yes but the Firebird was factory equipped with larger engines.
Add another resistor anode to gnd on 0 and 6? I made something like this for a 'US style' traffic light. I used one resistor on the common cathode and small switching diodes on the anodes. I still have quite a stock of those diodes. Isn't there a way to make the decade counter run backwards? I know, I could check. But I'm playing with cheap solar pathway lights now. ;-)
Your power supply supples positrons and negatrons? They must annihilate each other inside the 555. Was it getting red hot and emitting loads of harmful radiation?
Thank you, you accidentaly taught me how to get along with 4017 :D
How would you get the 4017 to drive a 12 volt relay to switch 120 volt light bulbs?
What kind of wire are you using to make your ground jumpers? I’d like to order a roll of that
Ah, but can you create the sound of the light as well?
I have one question. Where do you buy that kind of wire without isolation, for making bridges on breadboard or PCB?
You could find them by searching for bus wire. I bought mine at Jameco, but even Amazon sells them. They come in all kinds of length and sizes, so make sure you get the desired gauge for breadboard (usually 22AWG).
A "free" supply of short jumper wires are cut off remnants from LED cubes. They're pretty much uniform in size, enough to jump up to three breadboard holes. :-)
Can't you use less resistors if you put them on the cathodes instead?
@5:20 Sounds like that diode went wild
Nice, i remember more channels on the one in KITT how would you do that ?
Will this work with a 1uF electrolytic capacitor? I can't get my circuit to work. I tried this 3 times!!!!
Can I expect to see you driving around the street of HW, with this on the front of your car?
Can you use 10 leds
Nice video! :-) brings back some memories. I remember building that circuit in a long time ago not exactly like yours but in the same principle it might have been same circuit cuz it was a long time ago. :-) but still great job anyways.. to reminisce:-)
Where did you find the original parts? The LED boards and controller? I couldn't find on eBay or Banggood. Can you give us a link?
(Also, why not just use a single 200R on a common link to ground?)
Search ebay for "detonation led kit" - but only supplied with one LED board
Very funny to hear an electronics guy talk about cars. Even funnier that you're across the pond talking about American cars. I can't remember the last time I heard anyone say "Chevrolet". As the world has come to expect, lazy Americans dropped it to barely two syllables. "Chevy" is pretty much the standard. Just started watching your channel, like the work. Feel free to ask me any car question ;)
For hot circuit, or main venue to monitor? Numbers, or castiron see, I'm not coulomb nor sir Thomas. Negation? Reason local of eye in conjuncture w pergatous plates. Positron
Needs a blur and pause at the end of a cycle.
Modified Pontiac TransAm, I think.
could you make trail ? perhaps adding caps....
Creepy - Knightrider was on TV when I started watching this video.
I recently got rid of my 1979 Z28 Camaro mint. I still feel sick over that!
the circuit diagram?
I'd call the box scraps-to-be-reused
Now add capacitors to every LED to get the fading effect.
That wouldn't work would it?
Why not? A capacitor in parallel to the LED should charge up to the LED's forward voltage, and then discharge through the LED over time once the power from the IO pin is gone (since the capacitor would never go above the forward voltage, it wouldn't kill the LED).
The IO pin should be open drain though, otherwise you'd inject current into the IC, which you don't want. It could still work, though.