Reverse polarity protection 2 (CB22140E)

This circuit has an improvement over the previous one as it also has an LED indicator for correct polarity.

Schmitt Trigger Oscillator NCX2220 (CB20386E)
The NCX2220 circuit from NXP consists of a voltage comparator with low supply voltage and can...
10 Hz to 10 kHz VCO (CB8746E)
This 3-decade operating range VCO was found in a 90s Popular Electronics. The circuit uses...
Car Air Conditioner (CB15130E)
This circuit controls a fan in the car, according to the temperature, activating it automatically when the...