What is this solid state starting relay component?
That above component is called Positive Temperature Coefficient relay. In this application it is uisng as starting device for compressor in your refridgerator. It is used for powering the start winding for a short moment to help starting up the fridge compressor motor.


  what is the disk and how does it make this thing into a relay or equivalent?


The disk is the PTC thermistor material and the contacts and the plastics are for packaging and easy replacement.

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