Found in a 1980s American documentation, this circuit operates with 5 V signals requiring 55 cycles of 500 Hz for tone recognition. The circuit can be adapted to operate with other frequencies.
This circuit was originally designed for testing crystals used in color televisions, but it works...
This power amplifier circuit was marketed in Japan in the 1960s. The transistors are made of...
This circuit can generate signals from 100 kHz to 1 MHz depending on the L1 coil. For the medium...