Found in Popular Electronics from the 90s, this circuit mutes a scanner's speaker in the absence of a voice signal, thus eliminating the hiss.
May 2017 - Vishay's new AC0x..CS series safety wirewound resistors can now be obtained from Mouser...
This interesting configuration of optical triggering using an oscillator was found in a 90s...
The circuit shown in Figure 3 is used to control voice coil micromotors, such as those used to...