This circuit is from the 80's documentation. The integrated circuit is from the time but can be implemented with modern equivalents. The power supply must be symmetrical.
This circuit was obtained from an old American documentation, and practically any general-purpose transistor...
This light relay is powered directly by the power grid by activating a 110 V relay. The LDR is of...
We found this amplifier in a publication of 1990, but it can be mounted today with some exchanged...