Radio Shack sold many products, including a number of Power Supplies with the Micronta brand name. The Micronta Variable Power Supply, part number 22-123 is one of the most useful supplies ever made. Adjustable from zero (0) to twenty-four (24) volts at a self limiting current of just over one (1) Amp.

Up until the date this resource became available, a copy of the original Owners Manual that does contain the schematic diagram, didn't seem to be available on the internet/web. So, here's a free copy of that information for you to service these wonderful supplies as you find them on the used market. Also note, there were a number of generations of similar type and style supplies offered; search the web for part numbers like 22-121 and similar to see what those supplies are about. Also note the 22-121 is a dual, with selectable tracking variable supply.

Upon careful examination, one might note the similarities between the design of both the 22-121 and 22-123 Variable DC Power Supplies. Prior to the copy of the original manual with schematic being made available here ... in theory, one might have been able to repair their damaged 22-123 power supply by comparison with one half of the dual 22-121 schematic diagram. It's would have been mostly about using the "121 supply" as a basic reference. Although the concept of how the LM-723 regulator is operated is actually a very similar operation between the two supplies; there are notable difference that will probably throw off most people without a lot of experience with this type of LM-723 operation.

OK, Share and enjoy the Manual and please don't resell this information... " If you need help trouble shooting your supply, feel free to drop me a note.

Just So You Know!

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