This amplifier for hearing aid was found in a 1968 documentation using an integrated of the time. The power is from a battery, the consumption of 1.65 mA and the power of about to 1 mW.
The configuration shown in the figure is a second order filter (12 dB per octave) with an...
This transmitter, indicated for espionage applications, is permanently powered by the power grid....
This circuit was obtained in an old French publication from the 80s. The maximum power of the lamp...