PWM temperature measuring principle
PWM temperature measuring principle
the simple principle of PWM intelligent temperature control fan, in which has the function of PWM motherboard in addition to the temperature of the original circuit, a PWM control chip, the function of it is according to the measured temperature measurement circuit, a different duty ratio of PWM pulse signals, the pulse is a kind of square wave, in a cycle, the square wave signals of the high level of time to sort out a cycle, the proportion of wenling chi automotive air conditioning manufacturing co. , LTD. , called the duty cycle, the cycle is high level signal, the duty ratio is 100%, whereas duty ratio is zero, the most simple PWM control circuit, the fan on the circuit board of a control circuit, we put the simple understanding for a triode, and one of them and PWM square wave pulse connection, if there is a high level on this level, the triode in addition the poles in the off state, if the square wave pulse signal of the duty ratio is 50%, namely high level signal accounts for half the time of one cycle, then the triode in the week period between half in conduction state, in a cycle through the triode conduction time length, the morning a cooling fan to fan speed control easily, so the speed of the fan can do a variety of levels
