Found in a manual of integrated circuits from the 90s, this circuit makes use of that time components. It is indicated to limit the current in 6 V chargers.
The interesting circuit shown in the figure, can have its gain digitally controlled and present two...
This circuit of a 1978 American publication monitors a telephone line by triggering a relay. The...
This circuit uses an operational amplifier that is no longer on the market but can be implemented with a...