Crazy passive thermoelectrically powered gas safety valve: simple analog elegance!

Here we look at the ubiquitous gas valve found in stoves, barbeques, grills, heaters etc. that takes advantage of the thermoelectric effect (Seebeck effect). Instead of using a complicated system of sensors and microcontrollers, this valve and thermocouple package provide robust burner blowout protection with the simplicity of a copper tube. The K-type thermocouple tip when heated, provides 50mV to power a magnetic latch, that keeps gas flowing once the burner has successfully been lit. This tiny device manages to produce around a 1/4W of power, enough to hold the gas valve open. The moment the burner is blown out and it cools, the valve closes under spring tension, stopping gas flow. This integrated solution is as simple as it is elegant, and provides cheap but efficient safety for such a critical application.