This oscillator was found in the January 1987 issue of Radio Electronics magazine. The frequency is adjusted by C1, and the output has good symmetry. The power supply is typically 3 to 12 V.
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....