This circuit uses an LDR as a sensor to trigger an LED indicator at a preset lighting level. The power supply does not have to be symmetrical.
This experimental AM microphone was found in an Argentine publication from 1973. The recommended...
The integrated circuit is the 4093 and one of its four gates is used. The frequency is given by...
This TTL circuit was obtained in a 1985 Italian magazine, but it can be easily implemented, as the...