Found in a 90’s American documentation, this circuit indicates the frequency of input pulses up to 1 kHz. The circuit has a very explored configuration on this site.
This circuit has several features, such as timing to activate and deactivate, in addition to a...
The 4528 is a dual-retriggerable monostable that needs only the timing network formed by R and C...
This circuit from a 1978 American publication is used on vintage vehicles that still have contact...