Amplifier Project – Part 3: Power Supply

This is the third part in the Amplifier Project series.  This covers the entire process of building an audio amplifier based on the information located at Red Free Circuit Designs.  The first two parts of this project are located here:

Amplifier Project
Amplifier Project – Part 2

Not all of the parts have arrived yet, and that includes the capacitors for the power supply, but there is some progress to be made in the meantime.

I purchased a PCB from RadioShack to mount the components to, 276-158, but the bridge rectifier leads and heatsink mounts are too large for the holes on the board.  The holes could be enlarged, but little of the copper would be left.  Perf-board would be a better option.

The holes were enlarged using an x-acto knife, rotating back and forth on the front and back of the board.

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With the holes enlarged, the heatsink was test fit.  The legs are copper, so to hold it in place they were bent outwards slightly.

The process was repeated for the bridge rectifier.  Some thermal compound was evenly spread on the backside of the bridge.  I had silver paste style from CPU heatsink installs.  A hole had to be drilled in the heatsink to attach the bridge.

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The wires from the transformer were pulled through the perf-board, so holes had to be enlarged again, this time a drill bit was used, and a few extra holes were drill for the zip tie strain relief.

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While I had the knife out, it was a good time to make a template for the AC input connector.  That will come in handy later, when installing the finished project in an enclosure.  The connector was pressed into cardboard and traced, again using an x-acto knife, the shape was cut out.. simple enough.

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The power supply was tested and works, there is +/- 30VDC, just need the caps to clean it up (wish I had an oscilloscope).



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