This circuit was found in the Electronics Experimenter Handbook of 1961. The circuit uses door sensors and others. It is powered by 12 V from the car battery.
This circuit was found in a 90s Radio Electronics. It is intended to amplify the sound channel of...
A bridge with greater sensitivity and, therefore, lower consumption for the microcontroller...
Found in a 1964 magazine, this is a small headphone amplifier from 500 ohms to 10 k ohms (magnetic...