This circuit was found in Radio Electronics from the 90s. The CMOS integrated circuit is a PLL not easy to obtain today. The output stage can be exchanged for another one with greater power.
This circuit was obtained in an old American publication from 1974. The supply must be made with 5 V...
The purpose of this circuit is to keep the other phones on the same line muted when one is used....
August 2017 - STMicroelectronics' new DSL05 transient suppressors for 12 and 24 V voltages and...