Over Temperature Protection Circuit

A circuit is used to monitor and generate a trigger signal that starts the shutdown process at the high temperatures.

Over temperature protection circuit.

Over temperature protection otp 6. The current i temp is composed on the. When the over temperature protection otp is present we usually find a thermistor attached to the secondary heat sink the fan control unit usually uses a thermistor in the same heat sink. The diagram below shows a microcontroller temperature protection circuit that employs a voltage dividing circuit consisting of a combination of ntc thermistor and fixed resistors r s.

A wide variety of over temperature protection circuit options are available to you such as power tools. The same method is used in the design of this battery over charging protection circuit. Once the ptc cools down it permits the current to flow again. I believe 70 degrees in celsius is good because high power.

Frequently the monitoring circuit is built on a small printed circuit board that is attached to the main printed circuit board from the power supply. The transistor must be attached physically closest to the heat source ideally it should be attached to the heatsink of the power transistors. For example a zener diode of 7 v can be used in series with a 1n4007 diode. I made simple over temperature protection circuit which will shut down leds when a certain temperature is reached.

The resistance of ptc thermistors rises rapidly when a certain temperature is exceeded thus stopping the flow of current. Idea super brigth led light will include 100 leds which consume 1 watt per led. That is why there will be a lot of dissipating heat. When an overcurrent flows the temperature of the ntc thermistor rises and its resistance decreases thus suppressing the drive voltage of the microcontroller.

Simplified block diagram of the smart over temperature protection circuit it is important to note that the v drive signal is compared with an internal sawtooth signal to generate an internal pwm signal for the dimming. This characteristic is self regulating. Over temperature protection in a power supply is a protection system that shuts down the power supply when the internal temperature exceeded a safe value. The temperature monitor circuit works by comparing the voltage drop of a cold diode t1 with the base emitter voltage of a warm transistor t2.