The TAA300 integrated circuit is not common today. In fact, the circuit shown is from a Dutch Philips documentation from 1969. The output is 8 ohm speaker and 9 V power supply.
This alarm triggers a relay when the sensors are activated. Consumption is very low in the waiting...
In this circuit the photo-transistor signal is amplified by a Darlington step and then applied to a...
This good power amplifier, a few tens of watts, is part of an article in the December 1972 Radio...