This circuit uses uncommon Texas Instruments components today. The circuit is from an American documentation. Transistors are commonly used PNP. The display is 7 segment multiplexed.
The purpose of this circuit is to keep the other phones on the same line muted when one is used....
This circuit allows the use of a milliammeter in the measurement of low frequency alternating...
This circuit was obtained from a 1985 Electronic Desing. The circuit uses a Darlington which may be...