This is the circuit of a PWM temperature sensor, I will give you some details about the circuit:
- The Electronic control Module which supply power (+8V) at terminal (A)
- The Electronic control Module provide ground circuit at terminal (B)
- The output signal from the sensor at terminal (C)
- The oscillator, which provides the carrier frequency signal, depending on the application, the internal oscillator will provide a carrier frequency that can have the following approximate values 5kHz for temperature sensor
- A "Thermistor" element which varies its resistance with the changes of temperature, this variation is received by the amplifier and converted to a digital signal PWM.
- An output of the amplifier, which controls the base of a transistor and generates an output of "the duty cycle", measured in percentage of time that the transistor (this also provides protection against preserve circuits between C and B, and C and A terminals) "on" against time that it has been off.
Well I don't have enough experience in electronics so I want to know the sequence of how this circuit works:
- For example, with the oscillator, what does it mean to provide carrier frequency and what's the function of it in the circuit?
- How does the operational amplifier work in this circuit?
- How is the signal converted to PWM?
- How about the transistor; how does it work as a switch or what is the output signal at terminal (C)?