We found this time base of 0.1 to 90 seconds in a circuit manual from the 90s. The single-use transistors used are common and the frequencies given by the adjustment by the potentiometer.
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...