This 1977 circuit only allows the solenoid to energize if the right combination of switch positions is selected. The relay is 6 or 12 V depending on the low voltage supply used.
This amplifier for automotive use is from the Philips Databook of 1990. The integrated circuit must...
This fast-acting circuit uses any phototransistor as a sensor. The circuit drives a 30 V relay, but...
With this 1-transistor circuit we have a high input impedance and good gain. The circuit is from a...