Hi i build the tansistor oscillator of look mum no computer and it dosent work i canot find what is the problem ,its my first electronics project
Hare is a link to the projecthttps://www.lookmumnocomputer.com/projects/#/simplest-oscillator/

And some photos of the breadboard
It working on 15v 1.5a charger

I connect it to a amp in stereo aduio jack
The led is working and knob is controling its brightnes

Tnx for all the ansers im really stak

 

The pictures aren't clear enough to be able to trace the circuit.
Make sure you are using a 2N3904 transistor withe middle leg disconnected and the other two connected the right way round.
Do you have a multimeter?

 

The pictures aren't clear enough to be able to trace the circuit.
Make sure you are using a 2N3904 transistor withe middle leg disconnected and the other two connected the right way round.
Do you have a multimeter?

Hi i dont have a multimeter do resistors have + and - sides?

 

And the led suppose to blink (oscillate)?

 

Hi i dont have a multimeter do resistors have + and - sides?

Resistors can be either way round, makes no difference.

 

And the led suppose to blink (oscillate)?

The LED will blink if it oscillates slow enough for you to see.

Can you do some clearer pictures?

 

 

It soppuse to work i dont anderstand
The pot central leg and the left are conected like in the plans

 

Put an electrolytic cap on the output of charger. Re-check the polarity of the transistor and LED.

 

Put an electrolytic cap on the output of charger. Re-check the polarity of the transistor and LED.

I have only the 10 uf cap to put in beginig of the circuit?
The led is on
i think the polarity is good i try to flip them and the led swiched off

 

I think your charger is giving your circuit a 60 or 120 hz pulse..........blinking your LED.....you see it as on.

Try a battery or true filtered dc supply.

 

If you connect and disconnect one of wires connected to the 100k resistor do you hear clicks from the amplifier?
If you hear nothing when you do that then there is a problem with the connections to the amplifier.

 

I think your charger is giving your circuit a 60 or 120 hz pulse..........blinking your LED.....you see it as on.

Try a battery or true filtered dc supply.

If that was the case then the mains hum would be audible through the amplifier.

 

If you connect and disconnect one of wires connected to the 100k resistor do you hear clicks from the amplifier?
If you hear nothing when you do that then there is a problem with the connections to the amplifier.

I do hear clicks

 

I think your charger is giving your circuit a 60 or 120 hz pulse..........blinking your LED.....you see it as on.

Try a battery or true filtered dc supply.

I tryed a diffrent dc supply 19v and it had the same problem
Its suppose to work everything is in right way
The graund of the aduio jack suppose to go to the - (the minus) of the circuit?

 

Show us your audio jack connection. Have you connected across the channels.....or one channel and ground?

 

Do you have any other components like 100uF or larger capacitor, 100k or larger resistor?

 

Ground ,left and right. I have the 100 k resistor
The jack have 5 pins but i by noise the left and the right

 

I can't tell what you are doing without a clear accurate schematic. Good luck.

 

the schematic is in the link https://www.lookmumnocomputer.com/projects/#/simplest-oscillator/
i chacked the the audio jack with a signal of music from aux cable and it works so the jack and the amp are working
the problem is with the circuit but what it can be the current is flowing and the led is on its just dont produs sound what is the problem??