Abstract: A synchronizing circuit for a dubbing apparatus which is capable of a dubbing a signal played back from a playback unit to a recording unit in accordance with the operation of a dubbing command key. The synchronizing circuit essentially includes a circuit for checking the recording unit to determine if the recording unit has been brought into a stable recording condition and for producing a synchronous recording request signal, a device for driving the playback unit in response to the synchronous recording request signal, a circuit for checking the playback unit to determine if the playback unit is ready to playback and for producing a synchronous recording start signal, and a device for driving the recording unit into a recording mode in response to the synchronous recording start signal.

Abstract: A switching regulator which operates with low power consumption, which includes an input power supply source for supplying an unregulated DC voltage; an output network for supplying a load with a regulated DC voltage, the output network being coupled to a first terminal of the input power supply source; a switching element coupled to a second terminal of the input power supply source; an inductor connected between the output network and the switching element; the inductor, the output network and the switching element being connected in series relationship across the input power supply source; a first capacitor connected between the inductor and the first end of the input power supply source in parallel with the output network for smoothing the current flowing through the output network; a transistor connected at its collector-emitter path between said switching element and the first terminal of the input power supply source in parallel with the series circuit of the output network and the inductor, the transi