0-30V stabilized power supply: construction problem.

[sanket bhalsing]

HI SIR...

I have to face following problem

1) The output voltage does not varry.
2) Final output voltage is 7-8V.
3) LED ON
4) Current also not varry


PLZ tell me solution ......

 

[audioguru2]

On the original circuit:
1) The output voltage does not vary.
2) Final output voltage is 7-8V.
3) LED ON
4) Current also not vary.

Please post the answers to these DC voltage measurements:
1) What is the voltage at the output of U1? It should always be about +11.2V.

2) When the voltage pot P1 is turned from zero to maximum what is the voltage at the input pin3 of U2? It should change from 0V to about +11.2V.

3) When the voltage pot is at zero what is the voltage at the output pin6 of U2? It should be about -4V to +1V when the project has no load.

4) With the voltage pot at zero what is the voltage at the emitter of the driver transistor Q2? it should be about +0.5V when the project has no load.

5) With the current pot P2 at zero what is the voltage at the output pin6 of U3? It should be about +30V.