12 Volt bench supply

I needed a 12-volt linear bench supply for my radio projects. I searched on Ebay and bought the Condor HC12-3.4-A+ power supply pictured below. These two pictures are actually taken from the original Ebay listing, for reasons that I will explain below.

Note in the second picture the three leads (black, white, and black) coming from the transformer. I did not notice this, prior to buying the power supply, but these wires had been cut for apparently no good reason. You can see the other end of the wire extending out of the PCB. The others cannot be seen in the photo.

I lodged a complaint with the seller, explaining that there was no guarantee that I could properly re-wire the power supply nor whether it would work even if it was re-wired correctly. Fortunately, the seller agreed to refund my purchase. They didn't even require me to return the power supply. Since I had nothing to lose, I decided to attempt to repair the power supply anyway.

Through some Internet sleuthing and educated guesses, I was able to find sufficient vendor information to properly rewire the transformer to the PCB. Some further bench testing proved to me that the power supply was working properly and could deliver its rated current load.

Since it would be unsafe to operate an open-frame power supply without an enclosure, I elected to place it inside a re-purposed PC power supply enclosure. The enclosure I selected provided just enough room for the Condor unit and plenty of ventilation for conductive air flow. The first picture shows the Condor unit all wired up to an IEC AC connector, fuse holder, power switch, power-on LED, and binding posts for +12 volts (red) and ground (black). The second picture shows the finished power supply. It has served me well for several years. If necessary, I can always add a 12-volt muffin fan to the top of the enclosure to draw air over the power transistor.