Amplifier circuit with output coupling transformer, suitable for accurately injecting small signals into circuits carrying high currents

摘要

The subject of the invention is a voltage amplifier circuit which incorporates within its own feedback loop a broadband transformer TR of small size compared with the current flowing in its windings, by means of which the desired voltage component Va is injected into the output circuit, including the output load impedance Ro and the generator Vp of the principal current Ip flowing in Ro. The circuit design has the special property of ensuring that the magnetic flux φ0p in the core of the transformer due to Ip is instantaneously zero since the physical dimensions of the transformer TR are essentially independent of Ip and therefore linked solely to the value of the voltage component Va that the amplifier is required to transfer to the load circuit. IMAGE