Uploaded April 2026 | Updated September 2026, 2 weeks ago

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I wanted to see how these thermal fuses worked inside.

It appears to be two wires held in place with a high temperature resin base, and bridged with a low melting temperature solder surrounded by flux.

When the rated temperature is exceeded the solder bridge melts and the flux causes it to retract into a ball at each side, breaking the circuit.