This circuit allows the activation of a remote telephone bell made with a common piezoelectric capsule. The circuit does not need power, as it is powered by the line call signal itself.
This circuit was found in a Japanese documentation of the 70's. It uses transistors of the era and is...
Based on an Analog Devices LTC1540, this circuit consumes only 50 uA, serving to monitor the...
This circuit is from an Electronics Now from the 90s. It applies to almost any operational...