Nice Video which will be of great use to beginners. Circuit faults are not uncommon on these kits but can usually be fixed with a cut track and jumper wire.
I agree. I like how there's lots of kits now where you have to trouble shoot them too, by design. The smd competition ones are cool too. I bought a ton of them years ago to learn how to solder better. I dont cheat with paste either. Its amazing how a bunch of flux and a little hothair can straighten out all the crooked components. Took me like 10 kits before i got one to work properly hahaha
After all those Mailbag Mondays, I’m a little shocked that you don’t have a 16 pin socket at your disposal 😂. Have a great Labour Day weekend! By the way, I’m not colour blind and I can’t read those damn blue resistors either. I always buy the tan ones now.
I made a barrel jack tester with red and green LEDs a small panel meter and a bridge rectifier (the meter is a little off due to the diodes) Green for center positive and red for center negative both on its AC I used a zener for the LEDs
I think they screwed up with VT2 in trying to make a constant current source. They put R7 in the wrong place... It should be between emitter and ground and the collector tied directly to the display. I assume they tried this to keep the display LEDs the same brightness whatever the supply voltage.
I guess to display tri state, you'd need TWO LEDs and a resistor ? ;) For solder practice I used to build little models out of resistors.. like airplanes, helicopters.. locomotives (!) ... if you are good you make them work, with leds as headlights and a buzzer as chimney and such... a 1000 pieces resistor assortment doesn't cost too much.. I am always a little sad when those boards end up in a drawer never to be used.. those little toys you can dangle from the ceiling and have something to look at at least.. but yeah I mean to understand a circuit it is nice... I think your 555 timer circuit is much nicer than the probe though XD
@@pileofstuff Yes, certainly, perhaps, I mean maybe ^^ IDK if you know James Sharman aka weirdboyjim.. He has built a nice probe I think he also has schematics and stuff.. maybe not directly his invention ;)
@@Steve_Coates Yes, so to speak.. like a wireframe model of .. something. I like to build starships ^^ .. I couldn't find any videos on YT regarding that..(no hits for "resistor art") so POS might be the first to do it if he decides to do so :D
Ive been building alot of transistor circuits lately. Im currently half finished a 5 bit full adder using only nor gates. I need to cut and stain some fancy wood i have for an enclosure and it's done. Im going to attempt an smd only transistor clock next i think. Im going to just etch tiny grids with a bunch of mg chemicals brand stuff i got for free then foolishly paid for a bottle of liquid tin...... dont ever do that. Learn from my stupidity haha. Im too young to be retired and have too much spare time man. Its why im trying to give away half my components and motors and shit now to people in canada who watch this channel. No one tskes me up on my offer for free shit. All brand new, im a sucker for sales and impromtu project plans where i spend hundreds of dollars on shit thats so deep in a queue ill never get out of. If youre in canada and want some cool shit just text an address and when you receive at least 100 worth of shit you can pay the shipping if you dont mind. Im throwing random test gear in as well. Like lcr meters i foolishly bought more than one of and too many eevblog meters. Plus tens of thousands of leds and motors of every type. Ive been playing guitar more lately and would like to fit my recording gear in my hobby room and the guitars im restoring.
Constant current source. If only the resistor is used, as you said, the LEDs will light briter or dimmer depending the number of segments, so one digit (H) will be dimmer than the other (L)
@@andyfraser5876 Anyway, it seems it is working as intended, because I do not see any difference between the brightness of 3 or 5 segments. That LED is there to act as a zenner diode, not as LED. I used often this schematic (or the one with the resistor in emitter, or with two transistors, etc) to simplify the circuit, instead of using 510Ohm resistors in series with each segment. Maybe the values are a bit off, but it works as intended. Maybe pileofstuff can measure the display current in H/L states? Or, the voltage drop on the 51Ohm resistor? It should be around 5-10mA.
Yes, there are many ways to skin a cat, but these little kits are more for education than to produce a useable tool. You get to learn about that IC or a particular circuit method so that later you'll have lots of little building blocks in your brain to make something you actually want.
![BABYMONSTER - 'DRIP' M/V REACTION [WAS NOT EXPECTING THIS!!!]](http://i.ytimg.com/vi/t0Lpgr1jo3Y/mqdefault.jpg)
Great video. Thanks.
Nice Video which will be of great use to beginners. Circuit faults are not uncommon on these kits but can usually be fixed with a cut track and jumper wire.
I agree. I like how there's lots of kits now where you have to trouble shoot them too, by design. The smd competition ones are cool too. I bought a ton of them years ago to learn how to solder better. I dont cheat with paste either. Its amazing how a bunch of flux and a little hothair can straighten out all the crooked components. Took me like 10 kits before i got one to work properly hahaha
Time to order up an IC socket assortment
I've got plenty, but i wanted to build the kit as it was delivered.
Have burnt my fingers a number of times, doing "the reach-around." Tack those corners and keep things flat!
After all those Mailbag Mondays, I’m a little shocked that you don’t have a 16 pin socket at your disposal 😂. Have a great Labour Day weekend!
By the way, I’m not colour blind and I can’t read those damn blue resistors either. I always buy the tan ones now.
I do have some, but I wanted to build the kit as the seller delivered it.
There is a pulse detect via C1 and a diode. See what it displays on a fast switching signal.
I made a barrel jack tester with red and green LEDs a small panel meter and a bridge rectifier (the meter is a little off due to the diodes) Green for center positive and red for center negative both on its AC I used a zener for the LEDs
Time for a bodge wire and cutting traces to make that LED light up.
I think they screwed up with VT2 in trying to make a constant current source. They put R7 in the wrong place... It should be between emitter and ground and the collector tied directly to the display. I assume they tried this to keep the display LEDs the same brightness whatever the supply voltage.
Same thoughts, came here to say this.
Anyone who worked with chips in the '70s understands your caution.
Maybe that LED says "you just blew the transistor"?
😁
So wgy the LED if no=op?
No idea. Probably a mistake.
reverse eng. some of the cheap Dollar Tree, Dollar Store halloween items like the skull solar light, etc.
I guess to display tri state, you'd need TWO LEDs and a resistor ? ;)
For solder practice I used to build little models out of resistors.. like airplanes, helicopters.. locomotives (!) ... if you are good you make them work, with leds as headlights and a buzzer as chimney and such... a 1000 pieces resistor assortment doesn't cost too much.. I am always a little sad when those boards end up in a drawer never to be used.. those little toys you can dangle from the ceiling and have something to look at at least.. but yeah I mean to understand a circuit it is nice... I think your 555 timer circuit is much nicer than the probe though XD
A fun variant of a dead bug circuit.
That might work, but it would also draw current from the circuit under test, possibly de-stabilizing it, or giving a false result.
@@pileofstuff Yes, certainly, perhaps, I mean maybe ^^ IDK if you know James Sharman aka weirdboyjim.. He has built a nice probe I think he also has schematics and stuff.. maybe not directly his invention ;)
@@Steve_Coates Yes, so to speak.. like a wireframe model of .. something. I like to build starships ^^ .. I couldn't find any videos on YT regarding that..(no hits for "resistor art") so POS might be the first to do it if he decides to do so :D
Ive been building alot of transistor circuits lately. Im currently half finished a 5 bit full adder using only nor gates. I need to cut and stain some fancy wood i have for an enclosure and it's done.
Im going to attempt an smd only transistor clock next i think. Im going to just etch tiny grids with a bunch of mg chemicals brand stuff i got for free then foolishly paid for a bottle of liquid tin...... dont ever do that. Learn from my stupidity haha. Im too young to be retired and have too much spare time man. Its why im trying to give away half my components and motors and shit now to people in canada who watch this channel. No one tskes me up on my offer for free shit. All brand new, im a sucker for sales and impromtu project plans where i spend hundreds of dollars on shit thats so deep in a queue ill never get out of. If youre in canada and want some cool shit just text an address and when you receive at least 100 worth of shit you can pay the shipping if you dont mind. Im throwing random test gear in as well. Like lcr meters i foolishly bought more than one of and too many eevblog meters. Plus tens of thousands of leds and motors of every type. Ive been playing guitar more lately and would like to fit my recording gear in my hobby room and the guitars im restoring.
Removing VT2 and bridging C-E would allow the LED to work without affecting anything else. Why is VT2 there at all?
Constant current source. If only the resistor is used, as you said, the LEDs will light briter or dimmer depending the number of segments, so one digit (H) will be dimmer than the other (L)
@@sebastian19745 With the resistor values shown, the transistor will be switched hard on, so the bottom of R7 with be 0V at all times.
@@andyfraser5876 Anyway, it seems it is working as intended, because I do not see any difference between the brightness of 3 or 5 segments. That LED is there to act as a zenner diode, not as LED.
I used often this schematic (or the one with the resistor in emitter, or with two transistors, etc) to simplify the circuit, instead of using 510Ohm resistors in series with each segment. Maybe the values are a bit off, but it works as intended.
Maybe pileofstuff can measure the display current in H/L states? Or, the voltage drop on the 51Ohm resistor? It should be around 5-10mA.
@@sebastian19745 As mentioned in the video, the LED never reaches its operating voltage as it is limited to 0.7V by the transistor's B-E junction.
I agree. It doesn't serve any purpose that I can see.
Wouldn't it be easier to make the circuit using diodes instead of a CD4511 ?
Easier, sure. But you don't want to draw current from the circuit under test.
You could also use a couple of inverter stages. Or a few transistors.
@@pileofstuff I did'nt think of that. 👍
Yes, there are many ways to skin a cat, but these little kits are more for education than to produce a useable tool. You get to learn about that IC or a particular circuit method so that later you'll have lots of little building blocks in your brain to make something you actually want.
🤔
you should google translate to find out more on what's writen.
Why do you American/Canadians pronounce solder, as soder ?. It’s pronounce sold-der. 😂
Why does anyone pronounce anything using the regional pronunciation that they grew up with?
And why do Brits pronounce the L, but not the R?
Sodder
15:53... The Fix for the bad design is to put a 2K-10K resistor from the base of VT2 to the junction of R5 and LED1.
Or just eliminate the transistor - it's not really doing anything useful.
@@pileofstuff It supplies Negative (gnd) to the 7-Seg. Yeah just removing the tranny and jumping the R7 Resistor to Negatrive (gnd) would also do it