Household water heater thermocouple and power-open gas valve: Here's the riddle: (this is not a homework problem, it's a DIY thing) how can I use a small amount of electrical power to operate a natural gas valve? Background: Household gas water heaters have a built-in safety valve that needs a small current of DC to keep the valve open. They have a suspiciously large pilot, which heats a small thermocouple. The thermocouple provides electricity to keep the safety valvle open. If gas supply is interuppted, or the pilot goes out, then no more power from the thermocouple, and the gas valve closes. No gas build-up, and your home doesn't blow up. Nice, eh? How much power does a household gas waterheater produce? How can I generate the same amount of power by induction? If I have a hefty load (220V, 50A AC) nearby, can I wrap a coil of wire around this (very insulated) power cable to collect enough power to replace the thermocouple? (BTW-not using it to keep a gas line open anymore) Any other easy ways around this, or another solution? I thought of using yard irigation valves, which use 12V DV to operate, but I *think* they open OR close whenever they get power... I need a simple system, no ICs involved, as it will be outdoors with little protection from the weather. I want to gate to be open when power flows through large power cable nearby. Any suggestions of help appreciated. Thank you for your time.