This circuit was found in Mullard's transistor application manual from 1960. More modern transistors can be used. The zener diodes used have the indicated voltages.
This circuit generates pulses whose duration determines the position of a remote-control servo. The...
This circuit uses a piezoelectric tweeter to emit a powerful continuous sound above the audible...
This circuit generates sinusoidal signals that depend on the input oscillator. The circuit is from...