Most watchdog-timer ICs produce a single limited-duration output pulse when the watchdog timeout expires. Some applications, however, require the output to latch. This simple circuit provides a ...

Figure 1a shows a latching circuit based on an optocoupler, IC 1. If the off switch remains closed, pressing the on switch powers the LED in the optocoupler. Thus, the transistor in IC 1 turns on. You ...

Single-coil latching relays find use in signal-routing, audio, and automotive systems. To maximize their usefulness and cut power consumption, these coil currents must flow in both directions. Current ...