Huge Ass Power Supply

Well, I’ve finally done it. I’ve created a power supply that could destroy the universe as we know it. Well, not THAT powerful, but plenty large.

It’s primary (expensive) components came from a big pile of free stuff the girly pointed out to me. Throw in a few bits from RadioShack, SparkFun, and Maxim-IC and you’ve got a big nasty humming box.

As you can see by the image, it’s not quite all the way put together, but electrically it is functional. You can see in the above image the four large power capacitors (Three for cleaning and storing the rectified AC, and one for the 13.8V output stage). Behind the three in a row, you can see a tiny bit of the three transformers that step the 120V input down to 30V.

The 30V rectified output from the transformers is fed into the power board, where it is regulated down to 13.8V via the large power transistors on the right of the second image. These are controlled via the various parts best seen in the first image.

Then a microprocessor controls the relay that turns on and off output power so that the supply can shut itself off in case of short circuit, overheat, voltage fluctuations, or any other reason I choose. Here’s the logic board.

It uses an arduino processor connected to a Maxim-IC MAX127 which measures the voltages around the power supply, and also allows me to sense current flow via a resistor shunt.

The arduino also connects to these temperature sensors which are DS1621 sensors.

All of this information can be read out via this display, and controlled by the associated switches.

By the way, for those who are interested, I expect the power supply to be able to put out power in excess of 20 amps. However, this is of yet untested. One of these days I’ll connect a big ass load to it and see what it does.