This circuit uses a contactor having been found in a 1987 publication. More modern equivalent devices may be used. The circuit has neon indicator lamps.
This circuit is from the manual of the components used, from the 80s. The circuit is valid for...
This circuit from the 1980s uses an operational amplifier that is uncommon today. The circuit can...
This "debouncer" was found in Popular Electronics, using TTL technology. For this reason, it can be...