This circuit sources a Constant current to a load. The current is determined by R2. In the simulation the value is 0,6 A, given by R2 and the zener. This kind of circuit is used in battery chargers, motor control, SMA drivers, etc. In a pratical circuit the transistor should be mounted on a heatsink. Other transistors can be used for higher currents. The current is the zener voltage less 0.7 V (the voltage fall in the emitter –base junction of the transistor) divided by R2. This circuit also can be found in the MultiSIM BLUE as MSB002E.
Try to replace R2 by a potentiometer (10 ohm) in the simulation.
To download the simulation files and Netlist - click here (ni0011.zip)
