A common problem with on-delay timers is the timing capacitor reset. Typical timers (555 included) rely upon both complete power loss and finite elapsed time to assure that the timing capacitor is ...

This Design Idea shows how to use a 63¢ (Q=1) microprocessor reset voltage detector IC in a relay coil drive circuit to greatly reduce the coil’s hold-in current. When asked to estimate the coil ...