Abstract: Disclosed a high-frequency core bobbin which comprises: a winding bobbin member on which a wingding is to be wound; a first bobbin member for accommodating therein a predetermined portion of the winding bobbin; a second bobbin member coupled with the first bobbin coaxially so as to cover a portion of the winding bobbin member exposed from the first bobbin member, or put on the first bobbin member in the axial direction so as to shut off a space portion of a portion opposite to the winding bobbin member; and a leading-out guide provided on the second bobbin member for insertion and leading-out of lead wires of the winding.

Abstract: A switching power source control circuit comprising a comparator, a thin-out-processed pulse generator, a thinned-pulse detector, and a reset speed regulator, wherein: the comparator compares an output signal of an error amplifier with a variable reference voltage generated by the reference voltage regulator to generate a signal for performing thin-out operation in accordance with a voltage difference between the output signal of the error amplifier and the reference voltage; the thin-out-processed pulse generator generates thin-out-processed pulses on the basis of the output signal of the comparator; the thinned-out pulse detector detects the generation of thinned-out pulses or driving pulses while always monitoring the thin-out-processed pulses generated from the thin-out-processed pulse generator, and changes the reference voltage of the reference voltage regulator in the case where the thin-out rate is in a range of from 0 to 1/2 in the direction to make it difficult to perform thin-out operation to there

Abstract: A rectifier using a semiconductor active element as a rectifying element is connected through an overvoltage protection circuit to a terminal voltage comparator for comparing the input voltage and the output voltage thereof. A pulse control circuit is connected to the control terminal of the active element for controlling the same in response to the output from the terminal voltage comparator. Thus, the rectifier can operate at high frequencies with a high degree of efficiency.

Abstract: In a DC-DC converter of the type in which an inductance stores energy when a main switching transistor is turned on and releases the stored energy when the main switching transistor is turned off, a semiconductor active element is used as a flywheel element which is turned off when the main switching element is turned on, but is turned on to provide the path for the current established by the release of the stored energy, and the signal which is substantially in synchronism with the switching operation of the main switching transistor is applied to the control terminal of the semiconductor active element so as to cause it to turn on and off.

Abstract: In a DC--DC converter of the type in which an inductance stores energy when a main switching transistor is turned on and releases the stored energy when the main switching transistor is turned off, a semiconductor active element is used as a flywheel element which is turned off when the main switching element is turned on, but is turned on to provide the path for the current established by the release of the stored energy, an auxiliary diode is connected in parallel with the semiconductor active element and in the same forward direction, and the signal which is substantially in synchronism with the switching operation of the main switching transistor is applied to the control terminal of the semiconductor active element so as to cause it to turn on and off.

Abstract: A rectifier in which a semiconductor active element, which is a rectifying element, and a diode are connected in parallel in the same direction so that the degradation in rectifying efficiency due to the delay in rise time of voltage when the active element is turned on can be avoided.

Abstract: A device for stabilizing the output of a DC-DC converter of the type wherein smoothed direct current is supplied to a load through a series combination of a switching element which is controlled by a train of pulses from a pulse oscillator and an inductor. An astable multivibrator and a differential amplifier are connected in parallel with a DC source. The switching element is controlled by a train of pulses from the astable multivibrator. The differential amplifier compares the smoothed output from a smoothing circuit with a reference voltage and the two outputs therefrom are applied to two time constant circuits of the astable multivibrator so as to control the relative variation between the discharge times thereof.