Author Topic: Elektor Precision Power Supply Dec 1982 repair improvements  (Read 354 times)

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Offline oz2cpuTopic starter

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I scored this power supply from a local marked,
its design is : Elektor Precision Power Supply Dec 1982
the implementation was full of errors, I fixed it all,
so now I got a really nice extra supply,
see all details here:

https://youtu.be/ZeWiBPLUXrA?si=IXaLO073bgnQna6G

Any one else got ? or made this power supply from Elektor ?
Radioamateur OZ2CPU, Senior EE at Prevas
EMC RF SMPS SI PCB LAYOUT and all that stuff.
youtube : oz2cpu teardown
 

Online Doctorandus_P

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Re: Elektor Precision Power Supply Dec 1982 repair improvements
« Reply #1 on: May 30, 2024, 08:53:43 am »
It sure looks like a usable power supply.

One thing that is not shown on the pictures are the heatsinks. A power supply like this needs a quite big heatsink. the combination of relatively high voltage and current can generate up to around 120W of heat in your setup. Such power supplies usually have a relay to switch between secondary winding voltages to reduce the heat (and needed heatsink size). (Edit: Oops, it's shown in the video, but I'm not going to watch all 40 minutes of it.)

Tying a knot in the mains power cord is also .... frowned upon by many to say it carefully. Personally I am more concerned with the power switch. These tiny switches often have a mains rated voltage on them, but the meaning of that is that the switch is capable of switching such voltages, not that it is safe to do so. In it's current form the power supply also neither has PE, nor is it double insulated. My own preference would be to use a C13 socket on the back, and then connect the whole case to PE. But at the very least put some shrink wrap around the mains wiring, so that if a solder connection ever gets loose, it won't touch the housing and electrify it. I'm sure you've got plenty of experience to know such things. I don't know if care enough about such things to fix them though.
« Last Edit: May 30, 2024, 09:00:06 am by Doctorandus_P »
 

Offline oz2cpuTopic starter

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Re: Elektor Precision Power Supply Dec 1982 repair improvements
« Reply #2 on: May 30, 2024, 12:27:19 pm »
you can use the fast scroll bar to jump around the video time,
it is almost as smart and useful as when you scroll in a web page to seek exactly the most important things fastest possible :-)
so no need to see it all :-) different parts of it is for different people :-)

and you are right, that heatsink is a bit too small for full load all day,
maybe i can add a little secret voltage tap switch on the back ??
both transformers got a lot of useful taps for this,
less voltage = much less heat, let's say I need low voltage but relative high current out,
I dont plan to make auto switch relays,

I found the meter types he used, must be this type :

Rohde & Schwarz Selektomat USWV BN15221 1960
right here : https://youtu.be/qfgnnm4bHgQ

Radioamateur OZ2CPU, Senior EE at Prevas
EMC RF SMPS SI PCB LAYOUT and all that stuff.
youtube : oz2cpu teardown
 


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