This circuit is from the 1989 special edition of Radio Electronics Experimenter. The circuit was created with SMD components to be mounted on a keychain.
This circuit provides a signal of higher frequency the greater the intensity of the light incident on...
This circuit was obtained from a 1978 Practical Wireless. It generates a low frequency, low...
This circuit can be used as a lockable shield. A pulse activates the relay that remains on even...