Thermal resistor of negative temperature coefficient calls NTC thermal resistor again, it is the resistance of a kind of sensor that a kind of resistance increases along with temperature and reduces. Use extensively in all sorts of electron original, be like temperature sensor, but double entry fuse and self-adjusting heater.

 

Thermometer of cooling fluid of type of 1. electric heat and bimetallic piece type sensor

 

(1) structure

 

Thermometer of cooling fluid of electric heat type and bimetallic piece the basic structure of type sensor is shown 1 times like the graph.

 

Graph thermometer of cooling fluid of type of 1 electric heat and bimetallic piece type sensor

 

(2) principle

 

When ON of ignition switch buy, electric current has flowed to add hot coil, bimetallic piece 4 be heated are out of shape make contact detached, cut off circuit; Subsequently bimetallic piece cooling unbend, contact closes again again, circuit is put through again, relapse so, one pulse electric current is formed in circuit.

 

When cooling fluid temperature is inferior, bimetallic piece 2 be out of shape small, contact pressure is great, close time grows, open time weak point, the average of the electric current in circuit is big, this electric current has shed instruction sheet to add hot coil, the bimetallic of instruction sheet piece 9 be out of shape big, pressing with a finger slants place angle big, point to microtherm; Conversely, when water lukewarm taller when, the bimetallic in sensor piece 2 up warpage is big, contact pressure is little, close time is short, open time to grow, the average of the electric current in circuit is small, the bimetallic of instruction sheet piece 9 be out of shape small, pressing with a finger slants place angle small, point to high temperature.

 

Thermometer of cooling fluid of type of 2. electric heat and sensor of thermal resistor type

 

(1) structure

 

Its are basic the structure is shown 2 times like the graph. The main element of sensor of thermal resistor type is the thermal resistor of negative temperature coefficient.

 

(2) principle

 

When ON of ignition switch buy, bimetallic of thermometer of → of manostat of power source of → of switch of ignition of → of anode of accumulator of voltaic shedding classics piece of 6 add post of wiring of sensor of hot coil 7→ 15→ of crust of sensor of 14→ of 12→ thermal resistor builds negative pole of iron → accumulator.

 

Graph sensor of type of thermometer of cooling fluid of type of 2 electric heat, thermal resistor and manostat

 

When temperature of engine cooling fluid is inferior, the value of thermal resistor block of sensor is great, the average of the electric current in circuit is small, the bimetallic of thermometer piece bend be out of shape small, pressing with a finger points to microtherm; Conversely, when cooling fluid temperature is elevatory, value of thermal resistor block is little, the average of the electric current in circuit is big, the bimetallic of thermometer piece bend be out of shape big, pressing with a finger points to high temperature.