Measuring circuit of the dc component of the current flowing through theprimary winding of the output transformer of an inverter

Abstract From the Canadian patent

The measuring circuit comprises an integrator to which a signal representative of the current flowing through the primary winding of the output transformer of an inverter is applied. The integrator output signal is reset at the beginning of each period of the A.C. component of said current and is applied to a sample and hold stage whose output signal represents the integrator output signal just before it is reset. An intermediate stage is arranged between the integrator and the sample and hold stage to reduce the influence of load impacts by limiting the maximum possible variation of the output signal during the sampling period.