The basic constant current source circuit is primarily composed of an input stage and an output stage, with the input stage providing a reference current and the output stage delivering the required constant current. Aerospace Power Supply
The constant current source circuit is designed to provide a stable current to ensure the stable operation of other circuits. This requires that the constant current source circuit outputs a constant current, thus the device used as the output stage should have a voltage-current characteristic with saturated output current. This can be achieved by using a BJT or MOSFET operating in a saturated output current state. The AC constant current source employs SPWM high-frequency pulse width modulation, followed by inversion through an IGBT module and isolation output via an isolation transformer.
To ensure the stability of the output current of the transistor, two conditions must be met:
Its input voltage must be stable — the input stage requires a constant voltage source.
b) The output resistance of the output transistor should be as high as possible (ideally infinite) – the output stage needs to be a constant current source. 400Hz power supply
Basic constant current source circuits can be categorized into three types based on the different main components: transistor constant current sources, field-effect transistor constant current sources, and integrated operational amplifier constant current sources, etc.
