2022-11-09 (with much destructive work on this one done around 11/2022):

This here unit is a Stearns SINPAC CV50-165, which had some issues. I think I made it worse, although this particular unit was town apart quite a while ago... I still needed to finish up the electrical diagram and double check part values.

Bottom of Circuit Board; not much to see here; Markings: E200175 WM328DS-2 94V-0 4317 (Date Code?) Amazingly there wasn't more damage from using a weller soldering iron to de-solder the triac and terminals.

Board is slightly bigger than the CV16 to CV40 units at 1.83" x 1.69"

Top of Circuit Board. Markings: Stearns 849020011F. R14 and C3 weren't populated and may be for a R-C Line filter.

ST BTB41-600B rated at 40Amps... ( DATASHEET HERE (PDF, 12 Pages, 230KB) How do you attain a 50A SINPAC rating?) Heatsink 0.045" Thick x 1.25" Width x 0.875" Height.

My best attempt at an electrical schematic. Seems very similar to the other SINPACs I have recently torn apart. The potential addition of the R-C Filter and the larger TRIAC seem to be the only major changes


If you or someone you know finds this info useful and decides to start building something similar, please let us know. We'd like a royalty check and the option to buy some of your devices. ;)

Note: All electrical diagrams are believed to be correct as far as we're aware; however, there may be mistakes and omissions. You assume any and all risks by using these diagrams for anything other than a pretty picture to look at.


Part 1 of the un-obtainium saga: the CV40-165

Part 2 of the un-obtainium saga: the CV25-165

Part 4 of the un-obtainium saga: Alternatives - SAMUSCO ECS224L

Psalm 69:14