WATER TEMPERATURE DETECTING CIRCUIT FOR DETECTING TEMPERATURE OF COOLANT WITH SIMPLE STRUCTURE AT LOW COST

摘要

PURPOSE: A water temperature detecting circuit is provided to detect the temperature of coolant accurately by using a Schmitt trigger, and to cut down the manufacturing cost by removing the A/D converter and the microcomputer protection circuit. CONSTITUTION: A water temperature detecting circuit is composed of a temperature detecting unit(10) measuring temperature of coolant and outputting the variable voltage value according to the detected temperature of coolant, and a temperature adjusting unit turning on and off a temperature adjusting unit according to the output value of the temperature detecting unit. The temperature detecting unit has a resistor connected to a water temperature sensor(11), and the water temperature sensor connected to the resistor and the ground voltage end to detect temperature of coolant. The temperature adjusting unit comprises a Schmitt Trigger connected to a common connection node of the resistor and the water temperature sensor and the output end.