For 12.5VDC had to go with 25k by 22 ohm resistors with the 2n2222 and a 680uF 16v cap for 2 blinks per second. The 22 ohm resistor was between the LED and the common. The 25k made up of 20k and 5k in series was tied to the + of cap and emitter of the 2n2222. Tried going with values others suggested and this circuit is strangely voltage specific to resistor/capacitor uF values. I had hoped to get this to work with 5VDC going with lesser ohm resistors like a 330ohm for + to cap and transistor and direct connection between LED and common but nothing. The 2n2222 doesnt seem to get excited until around 9VDC and then you are messing with resistor values between + to cap and transistor and LED direct to common or a low ohm resistor to affect the blink rate between LED and common. LED grows from DIM lit to flash and out and then dim lit growing in intensity until flash. Anyone interested in using this circuit for a hard wired soldered project I'd suggest breadboard setup first to messing with values until you get it to flash at the rate you want and then solder up everything after confirming it does what you want as its strangely voltage sensitive to blink rate or on solid or LED completely off.
Yeah, you are not using the Transistor correctly and are relying on Collector/Emitter breakdown to flash the LED (not a good choice). Simply connect the Cap/Resistor pair to the Base rather than the emitter and the emitter to ground and drop VCC to your desired voltage (3.3 or 5v). The Cap will charge through the resistor until it reaches around 0.6v then turn on the Transistor and LED (transistors become active around 560mV and saturate fully around 0.9v). The time constant is RxC which, for your Cap/Resistor pair, will give you a little more than 1 second to reach 63% of VCC. You only want to get to 0.6v so thats way too fast a blink rate so increase the resistor from 4.7k to 47k to give you a blink rate around 1.5 seconds.
Ive tried this so many times and the led never blinks 😔 I have a sack of 2n2222 so I figured it may be a bad one and after 10 different transistors I gave up...
I think maybe the relationship between the positive voltage of the base in relation to some voltage above 5v+ or so (with 2N2222) on the Emitter causes the transistor to turn on allowing some charge stored in the capacitor to release to ground in reverse. The resistor prevents a dead short and the cycle continues at a particular input voltage depending on the capacitor and resistor value. Random guess though.
It might work because they are both NPN transistors with the same pinout. The one you want to use, uses a little bit more higher voltage to power it on. Give it a try, it might work.
@@SciTyeTech can you give me an example? I have 10k ohm, 10 ohm, 20 ohm , 1M ohm, 220 ohm , 1k ohm, 47k ohm, 22k ohm, 100 k ohm, 100 ohm, 470k ohm, 220k ohm, 47 ohm, 470 ohm, 4.7k ohm, and 2.2k ohm resistors
3 года назад
Either, the voltage needs to be changed, or the capacitors value. I tried using a 680 ohm resistor at 12V with a 1500 uF capacitor and it creates a signal at about 120hz.
Did you set the voltage to 10.7 volts? I too have had issues with this circuit. It will work, but only at a specific voltage. On this channel, I do not put anything fake. This channel is meant to educate and have fun making things. I have made things that don't work. If they don't work, they will not be uploaded. I did not make this channel to get view or popularity. It is for fun and for my own personal notes for me to look back on. Please make the circuit again, I assure you that it will work.
For 12.5VDC had to go with 25k by 22 ohm resistors with the 2n2222 and a 680uF 16v cap for 2 blinks per second. The 22 ohm resistor was between the LED and the common. The 25k made up of 20k and 5k in series was tied to the + of cap and emitter of the 2n2222. Tried going with values others suggested and this circuit is strangely voltage specific to resistor/capacitor uF values. I had hoped to get this to work with 5VDC going with lesser ohm resistors like a 330ohm for + to cap and transistor and direct connection between LED and common but nothing. The 2n2222 doesnt seem to get excited until around 9VDC and then you are messing with resistor values between + to cap and transistor and LED direct to common or a low ohm resistor to affect the blink rate between LED and common. LED grows from DIM lit to flash and out and then dim lit growing in intensity until flash. Anyone interested in using this circuit for a hard wired soldered project I'd suggest breadboard setup first to messing with values until you get it to flash at the rate you want and then solder up everything after confirming it does what you want as its strangely voltage sensitive to blink rate or on solid or LED completely off.
I'm glad I'm not alone on this lol
Yeah, you are not using the Transistor correctly and are relying on Collector/Emitter breakdown to flash the LED (not a good choice). Simply connect the Cap/Resistor pair to the Base rather than the emitter and the emitter to ground and drop VCC to your desired voltage (3.3 or 5v). The Cap will charge through the resistor until it reaches around 0.6v then turn on the Transistor and LED (transistors become active around 560mV and saturate fully around 0.9v). The time constant is RxC which, for your Cap/Resistor pair, will give you a little more than 1 second to reach 63% of VCC. You only want to get to 0.6v so thats way too fast a blink rate so increase the resistor from 4.7k to 47k to give you a blink rate around 1.5 seconds.
Ive tried this so many times and the led never blinks 😔 I have a sack of 2n2222 so I figured it may be a bad one and after 10 different transistors I gave up...
Did you adjust the voltage?
SciTyeTech did 10.7 and used all the same parts
I have no way to modulate the voltage and tried the same it won't work
Same for me and I have tried a tange of voltages
I think maybe the relationship between the positive voltage of the base in relation to some voltage above 5v+ or so (with 2N2222) on the Emitter causes the transistor to turn on allowing some charge stored in the capacitor to release to ground in reverse. The resistor prevents a dead short and the cycle continues at a particular input voltage depending on the capacitor and resistor value. Random guess though.
I did it with slightly different resistor values and with a step-up module which increased the output voltage to 5V for me, thanks for the circuit!
it's not working the same for piezo which I wanted
You're welcome. I am glad this was helpful.
Excellent video about this subject, great job!
Thank you! Glad you liked it!
does it work with a pn2222a transistor?
It might work because they are both NPN transistors with the same pinout. The one you want to use, uses a little bit more higher voltage to power it on. Give it a try, it might work.
Do i have to use those specific resistors.i dont have a 330 ohm resistor
You can, you just need to change the voltage.
@@SciTyeTech can you give me an example?
I have 10k ohm, 10 ohm, 20 ohm , 1M ohm, 220 ohm , 1k ohm, 47k ohm, 22k ohm, 100 k ohm, 100 ohm, 470k ohm, 220k ohm, 47 ohm, 470 ohm, 4.7k ohm, and 2.2k ohm resistors
Either, the voltage needs to be changed, or the capacitors value. I tried using a 680 ohm resistor at 12V with a 1500 uF capacitor and it creates a signal at about 120hz.
Brilliant as always❤️
Thank you!! I am glad you liked it!
Nice. Can made 2 LEDs alternating on/off ? That would be cool. Thx.
Not with this circuit, but I made this circuit that can. ruclips.net/video/szTQCP-aOVI/видео.html
10.7 volts?
why not explain how it works? we are here to learn
Cool😎
its fake i connect everything on the board and nothing happend
Did you set the voltage to 10.7 volts? I too have had issues with this circuit. It will work, but only at a specific voltage. On this channel, I do not put anything fake. This channel is meant to educate and have fun making things. I have made things that don't work. If they don't work, they will not be uploaded. I did not make this channel to get view or popularity. It is for fun and for my own personal notes for me to look back on. Please make the circuit again, I assure you that it will work.
@@SciTyeTech yes but the voltage is 10.6 at me and thanks for help great video always
This is what I mean, this circuit seems to be very picky. Thanks, you're welcome!
Faking this circuit is harder because the circuit itself is too easy lol. It also works with bc547
@@udhi_gn3893 lol!