Simple power supply, 0-30V, 500mA

[hcet]

Hi everybody,
I'm looking for a very simple power supply with above spec. It should have a very low parts count. The fewer the parts count, the better it would fit. Any idea is appreciated.
Regards and thanks, ep20k.

 

[Jack// ani]

Use a 500mA transformer instead of 2amps and this one will be perfect for you **broken link removed**

It is working fine for me.

 

[hcet]

Thanks Jack// ani,
but it has to be 0-30V and not 1.2-30V. So a supply based on a 317 is not my solution.
Best regards, ep20k.

 

[IanP]

To have regulation from 0V upwards you will need a small negative voltage.
And you can still employ the 317 regulator if as a reference to the ADJ pin you will use this negative voltage mentioned above. In case 317 te value should be -1.2 to -1.3V ..
Other option, if you don't require very good regulation, is to use a 33V zener diode and a potentiometer to control a darlington transistor. You will be able to adjust the output voltage fro 0 - 30V ..