In order to obtain a wide range continuously variable current limit without resorting to high wattage, nonlinear wirewound potentiometers, a diode and a resistor can be used as the current sensing elements. The diode operates as a current dependent resistor with a high resistance at low currents and vice versa. A linear potentiometer of low wattage taps off a proportion of the voltage developed across the current sensor and applies it to the current limit transistor as in conventional circuits. This varies the current limit value over a wide range - from milliamps to amps. Four types of current limit operations are obtainable which are illustrated graphically.
