Hi, I have following problem . The Thermopile probe ( 0.5V output @ 600 Deg C with internal resistance 2 Ohms ) drives gas valve solenoid with very low resistance ( approx. 0.023Ohm ) . Approximate holding current is 250mA . So there is only about 5mV on solenoid . I need to cut off this circuit with some kind of FEt , MOSFET or opto MOSFET . External circut to control this switch can have common ground with above circuit. Cannot use relay - external circuit does not have enought current to drive relay. I see problem with relativly low switched voltage ( only 0.5V ) and low resistance of fet needed . Any ideas what could be good solution ? Thanks Radim.
- posted
15 years ago