This circuit is from a 1980s Motorola documentation. The circuit can be set to fire from 60 to 120 V DC or from 42 to 84 V AC. The circuit has a forehead button that activates an indicator lamp.
This setting appears with variations at various points on this site. This is from a Motorola...
This circuit indicates through LEDs when an automotive fuse is open. ...
The circuit shown in the figure generates a rectangular signal whose frequency depends on C1. For...