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 was found in Radio Electronics magazine from October 1964. The circuit uses two...
This 5 V power supply for TTL, Shields and microcontrollers is old, and the components can be...
This automotive alarm uses common components and is suitable for old vehicles. The circuit was...