Abstract: The present invention provides a resonant power converter for changing the magnitude of a DC voltage. The converter includes a common magnetic core with three legs (an "EE" core). The core has primary and secondary windings wound onto a first outside leg, and a tank winding and control windings wound onto a second outside leg. Control switch means are provided for effecting alternate pulses of current flow through the primary winding to effectuate alternate flux flow, the control switch means and the primary winding having a predetermined parasitic capacitance with a predetermined delay time between the termination of a given pulse and initiation of the succeeding pulse. The secondary windings are oriented to conduct alternately in phase with the alternate flux flow, there being inherent in the first leg of the transformer a magnetizing inductance, such that the magnetizing current will be great enough to charge said parasitic capacitance in a controlled fashion.

Abstract: An apparatus for measuring the water content of an object to be measured comprises in combination a pair of optical filters for obtaining from the same source light a reference light having a wavelength not easily absorbed therein and a measuring light having a wavelength easily absorbable therein, an optical system for irradiating the object with the reference and measuring lights, an photoelectric converter for converting the reference and measuring lights to electrical signals, a temperature detector for detecting the temperature of the optical filters, a humidity detector for detecting the humidity of optical paths for the reference and measuring lights, extending from the optical system to the object, and a water content-measuring circuit for finding the quantity of water contained in the object on the basis of output signals produced from the photoelectric converter, temperature detector and humidity detector.