This circuit is from a 1968 documentation using one of the first integrated circuits available at the time, the TAA370. The circuit is powered by 1.3 V using a 200 ohm handset.
In the figure we have a circuit with two operational amplifiers 741 capable of doubling the...
What differentiates this circuit from the previous one is the need for a much smaller current to...
This circuit was obtained in a Maxim documentation from the 90's. The circuit applies to...