Linear Actuator reprise.

    For the last couple of years, the solar array has been stationary and the motor not used. A relay card, rewired by me, burnt up. The actuator motor drew too much current for the copper etch traces when the actuator reached the limit of movement and increased current flow.

   I've installed a limit switch to help prevent future failures. I an also installing solid state relays with a rating almost three times the maximum  required by the actuator motor.

   For the last few days, I've been researching SSR's ( solid state relay). I ran across a suitable design that uses mosfet semiconductors and opto-couplers.

   All day, today, I've been breadboarding and testing circuits. I have prototyped and tested the design I want to use with positive results.

   The next step will be to assemble the final breadboard circuit and install on the Raspberry Pi 3B. The new circuit replaces the custom-wired quad-relay card. The mechanical aspect will be no longer an issue. No welded contacts. No custom wiring. No burnt etch traces.

   The parts come from my stock parts stores with some coming from a Samlex Cotek 1500w inverter that stopped working years ago.

   The extra solar energy will come in handy this winter.