Hello, the pin connection of the 431 triode is as follows:
1. G pin: ground or negative electrode, generally used for the input end of the regulator.
2. V pin: output terminal, used to output stable voltage.
3. K pin: regulating end, input regulating voltage to control the size of the output voltage.
It should be noted that a resistor needs to be connected between the G pin and the K pin to limit the current, and a pair of filter capacitors are also needed to stabilize the output voltage.
One pin r end, two pin a end, three pin k end, one pin is connected to the sampling voltage input, two pin ground, three pin output control voltage