NTC and PTC in Television Circuit

Have you ever seen a tube televission turn off after ON too long?, and after that turn on automatically. If yes, this because a sensor in the circuit names PTC (Positive Temperature Coefficient) and NTC (Negative Temperature Coefficient). This sensor is sensing a termal for hot termal (PTC) and cold termal (NTC), it's cool right. Yeah, let's learn it deeply.

Picture 1. PTC with green one and NTC with the black one

From picture 1 above we can see the PTC with the green one and NTC with the black one, it is already marked. PTC and NTC like a resistor with condition by temperature. This device plug in power supply switching system.

Picture 2. Circuit around Power Supply Switching Televission

PTC and NTC located before bridge rectifier, we can analisys, if temperature high (be hot) the resistancy of PTC will increase and if temperature is down (be cold) the resistancy of PTC will decreas. It's different with NTC, if temperature down (be cold) the resistancy of NTC will increase and if temperature is high (be hot) the resistancy of NTC will decrease. Next symbol of NTC / PTC: