In this Design Idea, we look at how electromechanical relays display hysteresis behavior that is surprisingly similar to the solid-state Schmitt trigger circuits, and how they can be used for many ...

Use an LM1881 sync stripper to trigger a 555 timer set up as a one shot, make the time period longer then one video line (~65uS), and use the output of the 555 to control the relay.

I know, I know—discussing the subject of a relay-based sequence switch in the age of omnipresent microprocessors seems to be a waste of time. After all, relays have been in use for many years. Is it ...