This variable 1 A power supply with voltages up to 30 V was found in an article in June 1986 Radio Electronics magazine. The 723 IC is well known to magazine readers of the time and even today.
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...