This circuit is used to protect an amplifier from excessive power output that would cause problems for the speakers. The circuit is from the January 1985 issue of Radio Electronics magazine.
The oscillator in figure 1 can be used in alarm, call or warning systems, producing a sound of...
This circuit is from a 1973 documentation. In it we have the way of using a FET as an input of...
This circuit is for traditional old-style telephone lines found in an American 1980s...