This circuit activates a relay after a time given by C1 and R1. The circuit is from a Radio Electronics from December 1974. The relay voltage is the same as that used in the power supply.
In the figure we have the transmitter of a data transmission system with optical fiber suggested by...
This circuit was found in a 1969s American documentation. With modern components, it can be used...
The maximum input voltage of this circuit is 20V and the output current is 250 mA. The circuit is from...