modifying two converters for clean DC using a motor sports shunt rectifier / regulator?

Thread Starter


Joined May 23, 2016
Hi Folks!

Working on modifying a 130 to 12 and 15 VAC low voltage lighting converter and a resonant transformer with half wave rectifier (RV converter) for clean DC power for two reasons. the low voltage lighting controller is a portable power supply to run presentation lighting (blinking color changing chasing RGB srtips) the other is for a dc power supply for the shop for testing, and operating 12v automotive things, charging batteries etc

Anyways, I have modified the 200w lighting converter for clean(ish) output by using a full wave rectifier, and two capacitors of sufficient uF (i forget how much, but it was over what was calculated for 200w) from a computer power supply. the output is clean enough to not confuse the RGB stips, that's the best I can offer, as I don't have an oscilloscope. I was in a time crunch and had to whip this up for a low demand display (50w) and it worked. but now I want to make sure its going to last.

my worries are that as assembled my rectifier has no heat sync and zero airflow, and at max output I feel its going to cook the rectifier. so while I was searching I had an "AHAH!" moment for a cheap rectifier. a motor sports regulator / rectifier. usually as designed, they take about 12-30vac depending on the engines rpm and rectify and shunt the extra voltage and output a steady 13v not the most efficient design, but, very inexpensive.

I was thinking, since my displays are outdoors, one of these regulators would do the trick as they have large heatsyncs, are sealed for rugged and pretty torturous use. also being that output right now is 13.5 from the converter so it wouldn't have to shunt much. as well same with the RV converter. I plan on keeping the capacitors to clean up the output. and I will have to buy a capacitor for the rv converter output.

So, am I on the right track here? Cheap is the name of the game for me, but obviously I don't want to spend money to build something that then fails, that's the anti cheap. should I go for a $20 regulator, or just rob more parts from the computer power supply?


Joined Jun 19, 2017
Please, draw and post a schematic diagram of the Power Supply that you have created.
Is it an unregulated "step-down transformer + diode bridge + capacitor" type Power Supply ?
Some part numbers for the components, especially the diode bridge, would help.
What is the max amps that you will draw from this Power Supply?

Does the "motor sports regulator / rectifier" typically control an Alternator, using the Field Coil?
Please provide URL to web page and Model # for this device.