Operated directly from the power grid, this detector was found in an 80's RCA documentation. The sensor is an ionization chamber. The SCR triggers a warning siren.
Found in a Popular Electronics from the 90s, this circuit has a configuration that has been widely...
This conventional slow-moving circuit uses incandescent light bulbs, but can be changed to use...
In the figure we have the way to implement an inverter using a relay. The contacts used are NF and...