This 1974 circuit uses two 555 integrated circuits in a very traditional configuration. The circuit can be powered by voltages from 9 to 12 V and for greater volume an amplifier stage can be added.
This simple calibration circuit consists of a crystal oscillator that generates an accurate 100 kHz...
This circuit produces a low frequency magnetic field used in old inductive remote controls with a...
We found this circuit in a European publication from the 1970s. The transistor is made of...