This 20W amplifier was found in 283 circuits from the 90s. The MOSFET admits equivalents. The power supply must be dual, and the transistors must be mounted on good heat sinks.
In the figure we show how to use a 555 to control an SCR or another type of thyristor. Resistors R1, R2...
This circuit was taken from the 1974 Ferranti transistor manual. Transistors are common types at...
This interesting intercom circuit was obtained from an Argentine publication from the 1970s....