Found in a 1966 General Electric documentation, this dimmer should only be used with incandescent lamps. The Triac is according to the power of the lamp.
Of course, other frequencies can be generated by changing the components. The circuit generates a...
This circuit was found in a 1974 publication. It provides a tone indication of the temperature sensed by...
This spy transmitter can be plugged directly into a power outlet. The power comes from a regulated...