Found in American documentation from the 90s, this circuit can measure frequencies on a linear scale from 0 to 1 kHz. The components can be changed to measure other ranges.
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...