Battery Condition Test (CB4969E)

We found this car battery status monitor circuit in an American 80s manual. The circuit has its trimpot trigger setting by driving an LED indicator.

RIAA Equalization Amplifier (CB4952E)
This circuit is from an 80's documentation. The integrated circuit is from the time and the...
Thermostat with Trigger (CB923E)
This circuit was obtained in an old English magazine (TSI) 1998 and consists of a Schmitt trigger...
Voltage Controlled Oscillator (CB4168E)
This VCO with a common operational amplifier was found in an old American documentation. The...