This circuit is from an American documentation from the 90s. The transistors are of power and must be equipped with good heat sinks as well as the integrated voltage regulator.
This circuit is from the 1968 ARLL documentation. The MOSFET admits equivalent and the coil...
Schmitt Triggers convert a signal of any waveshape in square signals or pulses. The circuit shown...
I found this circuit in a Popular Electronics from November 1993. It allows to use a 12 V x 1 A...