A thermocouple consists of a pair of electrical conductors made of different metals, which are connected to each other at the end and, due to the thermoelectric effect (Seebeck effect), provide electrical energy from heat at a temperature difference along the electrical conductor. QS Safety thermocouples deliver about 0.3 mW at over 400°C. The thermocouple provides electrical energy from heat depending on the temperature, more at higher temperatures and less at lower temperatures. The thermocouple is placed next to the burner so that it protrudes into the gas flame, is enveloped by it and thus heated. More electrical energy is supplied when the burner is burning and less when the flame is extinguished.