This circuit was obtained from an 80's Radio Electronics. The circuit decodes “scrambled” or sinusoidal encoded signals by providing an audio signal at the output.
This circuit can function as a light alarm by changing the sound when light falls on the sensor....
In this circuit the photo-transistor signal is amplified by a Darlington step and then applied to a...
This is a traditional complementary-output transistor amplifier sourcing 2 to 4 watts to a 4 ohm...