Voltage Level Detector (CB22135E)

We found this circuit in an English documentation from the 80's. Transistors are general-purpose types.

Voltage Controlled Oscillator RC4558 (CB19784E)
This VCO makes use of an RC4558 which is an operational amplifier with characteristics close to...
Low battery indicator 555 (CB9551E)
This circuit can operate with different voltages, depending on the zener used. We found it in a...
Timer Using 7555 (CB860E)
This circuit can be used in the car to control the windscreen wipper or with other appliances at...