This speaker overload protection circuit was found in Radio Electronics from the 1980s. The circuit uses a 9 V relay but can be powered by 12 V for a relay of this voltage.
Found in an Electronic Design from the 90's, this circuit uses common components. The circuit is...
When the sensor receives light, the relay closes its contacts and remains so even after the light...
This circuit produces pulses of 90 V at intervals that can reach 5 minutes. The circuit is from a...