This high input impedance circuit was found in American documentation from the 1980s. The power supply must be symmetrical. The circuit applies to modern operational.
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...
This circuit turns on an old cassette recorder when the telephone rings, thus enabling the...
This circuit can be used in panel signaling with common incandescent lamp. The lamp will flash at a...