Many varieties of ON/OFF control circuits use some form of flip-flop that responds to a pushbutton switch or other control input. These all have volatile memory and default to an OFF condition if ...

It’s easy to get caught up in the excitement of creation as we’re building our latest widget. By the same token, it’s sometimes difficult to fully appreciate just how old some of the circuits we use ...

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 ...

When you first clamp your hands, mic detects the sound and triggers the 555 timer via the operational amplifier. The timer stretches the signal and applies it to the clock input of the flip-flop.

This light activated relay circuit presented here uses the 555 timer IC and a light dependent resistor or LDR to form a light sensitive relay in an intruder alarm system or for switching on a lamp at ...