a relay driver circuit , suitable for controlling a bistable relay , includes .. . iadd . a transformer which handles both an information signal and a control signal and a storage device . the control signal is provided by a low current low voltage source . . iaddend . a first switching circuit couples the storage device to the bistable relay when the first voltage level exceeds a predetermined value . the charge on the storage device is dumped into the relay and forces it into a first state . a second switching circuit is coupled to sense the voltage on the storage device and the voltage on the low voltage source . when the voltage on the low voltage source falls below the voltage on the storage device , current flows from the storage device and forces the relay into a second state . the reset time is within 100 μs .