This circuit uses common components at the time of its publication in the 1980s. The circuit can be made with modern equivalent transistors. The input signal is sinusoidal.
This circuit provides a signal of higher frequency the greater the intensity of the light incident on...
This circuit was obtained from a 1978 Practical Wireless. It generates a low frequency, low...
This circuit can be used as a lockable shield. A pulse activates the relay that remains on even...