This circuit can activate a powerful lamp or call system when a telephone call occurs. Suitable for hearing impaired or noisy places it was found in American documentation in the 90s.
This circuit multiplies the input resistance of an operational amplifier. As the indicated...
This conventional flip-flop configuration with two transistors was found in documentation from the...
The input impedance of this amplifier is of the order of 1014 being the same indicated for pH...