Farnell Power Supply D30 2

[Edgard]

Hello,

I obtained an old powersupply Farnell D30 2 in non working condition.
I would like to make an attempt to repair it but i have no manual or even a repair manual.
Is there anyone who can help me with at least a schematic.

thanks for any reply.

greetings from a hobbyist from Belgium.

Edgard

[JacquesBBB]

You should post a picture. Many units are distributed on different names.

[anachrocomputer]

I have one of these power supplies, and I have written up a blog post about fixing it:

http://anachrocomputer.blogspot.co.uk/2013/04/fixing-big-farnell-psu.html

Could you post a description of the fault(s), with photos? I can probably help you with diagnosis, even if we don't find a schematic. Those old Farnell PSUs are very reliable, and very fixable if they do fail.

I don't know of any other names that Farnell used. But very similar supplies were made in later years by Thurlby-Thandar.

[bd139]

Farnell supplies usually die because the engineers didn’t bother to put protection diodes across the pass transistor or output. So if you connect something which can source voltage like a battery or large cap then shut the power supply off at the primary side it’ll blow up. Stupid stupid design.

Always check the pass transistor and driver transistor first. Probably ok apart from them. Then stick a big ass 1n5401 across the unregulated to regulated connections on the pass transistors and across the outputs.