The autopilot switch images below came out of a Regency Gas Fireplace. The pilot flame could not stay on so I took this part of the fireplace. It is a White Rodgers Autopilot model 3056-2. The first photo shows a partially disassembled switch. I think the "nail looking thing" at the end of the copper wire is a thermalcouple. The copper wire is soldered/welded to a rigid copper dome/hat. The second photo shows the switch completely disassembled. The copper hat sit on top of a plunger. The plunger is made of two parts, the part that came into contact with the copper dome is made out of plastic. The bottom of the plunder is made out of copper.
For the switch to work, the plunger has to be depressed down, overcoming the force of the coil spring and another spring, to connect the two bladed terminals together.
I don't see any thing that can take the current from the thermalcouple to induce a force on the plunger to push it down.
Please explain the mechanism in which the thermalcouple could force the plunger down to complete the circuit.
Thank you very much!
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