Hello,
I tried to make a slow speed speed oscillation with a PUT but it doesn't work. Just, as soon as I gave the power (6V DC), LED flushes weakly and then light gone. Capacitor reaches 5.9 volt and it doesn't discharge. I don't find out why. Could you check the circuit and tell why it doesn't work? Thanks...
(All components work well individually and transistor is 2N6027)

 

My simulation of your circuit did not work either until I reduced the 330kΩ resistor to 300kΩ (or less), so you might try that.

 

I reduced it to 300kΩ and also 200kΩ but it did not work again. So, I can not proceed in my project.

 

Are you sure you have the pinout of the PUT correct? The cap should connect to the emitter. The anode should connect to the programming resistors.

 

I think all pinouts are correct. I've attached my circuit on breadboard.

 

Try increasing the value of the two gate resistors from 10kΩ and 20kΩ to about 100kΩ and 200kΩ.

 

On the breadboard you have the gate connected to the programming resistors instead of to the cap.

 

It doesn't work either. It works as in the video I have attached. I have tried varied resistors as well but It never worked. Should I calculate value of Rg (R2*R3 / (R2+R3) and then do it again?

 

On the breadboard you have the gate connected to the programming resistors instead of to the cap.

Gate is already connected to the programming resistors. Cap is connected to the anod.

 

Can't open .rar files .

Gate is already connected to the programming resistors. Cap is connected to the anod.

Precisely. It should be the other way round.

 

Can't open .rar files .

Precisely. It should be the other way round.

I did circuit by the reference of make electronics book as below. I guess my circuit is same except resistor values. Could you please show your advice on picture. I am sorry I couldn't get how to replace cap the other way round.

 

On the breadboard you have the gate connected to the programming resistors instead of to the cap.

I'm confused.
That's the way it should be (gate to programming resistors and capacitor to anode) as shown below.

 

I'm confused.
That's the way it should be (gate to programming resistors and capacitor to anode) as shown below.

View attachment 109480

I am also confused and exhausted to try it Now, I am going to try this circuit.

 

Below is my LTspice simulation of the circuit working.
Of course that's no guarantee that the real circuit will work with the same values.

Try increasing the power supply voltage to see if that makes a difference.

 

Oops. My bad.

 

Try shunting D1 with 1K so that cap. can almost fully discharge.