Thermal sensors in Radiator, engine, and 4WD transmission temperature sensing
Reed Switch based normally closed thermal cut-outs are useful in a wide range of automotive applications, either to take certain action like switching on a cooling circuits or to trigger dashboard indications. Due to their sharp trigger signal, such devices find applications in place of bimetallic strips, thermistors and thermostats for over-heat protection or precise temperature switching. Thermal reed sensors can be mounted on the engine block to sense high temperatures and give an indication on the instrument panel. Thermal reed sensors, capable of switching loads as high as 60W, when used inside a radiator, can directly be wired to the radiator fan. When the temperature reaches a high, the fan is turned on, and after say 10°C less, the thermal reed sensor cuts off supply to the fan. They can also be mounted on the four wheel drive transmission system to check for over-heating. Thermal reed sensors can be designed to have temperature differentials as from 2°C to 10°C.