A zener diode can be used to set the Base voltage of Bipolar Junction Transistor (BJT) Current Source. That voltage, offset by approx. 0.6V, will be across the Emitter’s current setting resistor regardless the supply voltage. As long as the supply voltage is high enough to power everything in the circuit. NPN BJT drops approx. … Continue reading "Fixed Current Source using NPN BJT Sink and Zener Diode"
