Tuesday, October 16, 2012

Solid state relay out of monster SCRs

This is what I made out of the PowerSem modules I salvaged from the motor soft start controller. 
The SCR is connected back to back making it analogous to a triac. 
PCB was hand drawn due to it's simplicity and my general laziness.

MOC3020 triac output optocoupler drives the "big triacs" with mains AC. The LED input is driven from low voltage DC as one would expect.

I think the resistor in this one fits a 12V input but 3.3v shouldn't be an issue with another one. Fairly large AC loads could be switched on the output considering the power rating of these SCRs.

Tuesday, October 2, 2012

[Random Teardowns] Industrial motor soft-starter

Device: Telemechanique Industrial Motor Soft-start controller
Origin: Gift / Acquaintance
Reason for teardown: That's why I got it
Impressions: Obviously something went horribly wrong inside this thing and the pins of the high current relays prompty evaporated when it happened. It contained some fairly useful components that survived the ordeal. The large heatsinked modules are POWERSEM 100A (that's one hundred amperes) dual thyristor(SCR) modules perfect for heavy duty AC power controllers or solid state relays (which I ended up making out of them). The mains tranformer also found a new home since in a garage door opener remote control box.


 That's a PIC.. I can probably use that too for something (not really.. I do AVRs but too lazy to do anything with those even nowadays..).

 Another evaporated pin

Mains and pulse transformers