Re: Repair Vintage DC Power Supply, Sorensen DCR-B series 2700-Watt 600-4.5B

Greetings,

Thank you very much for the pointers and direction. Reconfiguration of the resistors on the control PCB enabled an output voltage of 600V. This required removing the (4) 150k resistors from the old board and populating them on the "new" board.

Now I would like to perform a load test. Below are pictures of a very large 5.5 OHM resistor. What is the recommended procedure for load testing this PSU. What size wires are required from the terminal block to the resistor?...

Re: Repair Vintage DC Power Supply, Sorensen DCR-B series 2700-Watt 600-4.5B

Hello eccerr0r,

I see the voltage will adjust down to zero and up to about 190V over the full range of the knob. It does not suddenly drop to zero. This was verified using an external multi-meter. I do not have a load resistor that can support this wattage, for now I would like to defer the load testing.

I will test voltage across the primary filter capacitors and report the voltage.

Do you have any other suggestions to further troubleshoot this power supply?...

Re: Repair Vintage DC Power Supply, Sorensen DCR-B series 2700-Watt 600-4.5B

Hello,

Service manual located here: [url]https://cdn.badcaps-static.com/pdfs/45d3826ec2a53fad7f142619b5565efe.pdf[/url]

The chassis holds some huge capacitors, aluminum heat sinks with some components and large transformer. Any thoughts on how to proceed?

Thanks,
MancoastRe: Repair Vintage DC Power Supply, ...5efe.pdf[/url]

Re: Repair Vintage DC Power Supply, Sorensen DCR-B series 2700-Watt 600-4.5B



At this time I am traveling and haven't taken any pictures yet. When I get back home in a few weeks I will post plenty of photos. Am I allowed to post the external link to the repair manual with the factory drawings and schematics on these forums?...

Re: Repair Vintage DC Power Supply, Sorensen DCR-B series 2700-Watt 600-4.5B



Hello goontron,

What are the instructions to test the diodes? By diodes are you referring to the SCR's? Do you suggest inspection of the DC output with an o'scope for noise analysis?

Thanks,
Mancoast...

Greetings,

I seek relevant forums and communities to document my issue and to formulate structured dialogs. With respect to the repair and restoration of a vintage DC power supply from the early 1980's, I need advice and direction. Majority of my experience exists on the computer designing systems, but this project sparks a new curiosity with vintage electronics restoration.

The Sorensen DCR 600-4.5B DC Power Supply, 0-600V, 0-4.5A, 2700W rests on my workbench with the system input voltage supplied from 208V 3-phase 20A because the Sorensen factory default M1 configuration...

Re: New Members - please post your introductions here

Hello, my name is mancoast. I am a systems engineer and enjoy restoration of vintage technology.