Abstract: The variable attenuator and variable current shunt of a battery-powered auto-ranging digital multimeter uses latching relays, each of which, since it is stable in each of its two switching states, requires only a current pulse to change its state. The circuit which operates the relays provides a drive pulse only when the desired relay state differs from the actual state, thus minimizing the power required, and includes a tank circuit for minimizing disturbance to the multimeter power supply. To ensure that the tank circuit can recharge, each relay is driven by a tri-state output.