DC to DC Converter

DETAILED DESCRIPTION It is an object of the invention to provide a power supply circuit high in efficiency.
It is another object of the invention to provide a power supply circuit which can produce a stable DC voltage at its output terminal for a large variation of loads.
It is a further object of the invention to provide a power supply circuit which can always produce the maximum output power even if a load connected to its output terminal is varied.
It is a still further object of the invention to provide a power supply circuit which can achieve the effects the same as those set forth above by varying the inductance of an inductive element in response to the variation of a load as reflected by the DC current in the output circuit and the voltage at the output terminal.
It is a yet another object of the invention to provide a power supply circuit which is simple in circuit construction but can produce the maximum power and a stable DC output voltage even if a load is changed in magnitude.
According to an aspect of the invention, a power supply circuit is provided which comprises a DC voltage source, inductive means supplied with a DC voltage from said DC voltage source, switching means connected to said inductive means, means for converting an AC voltage produced in said inductive means by said switching means into a DC voltage, an output terminal connected to said converting means, means for detecting a DC voltage delivered to said output terminal, a modulating circuit for producing a modulated signal in accordance with an output signal from said detecting means, means for applying the modulated signal to said switching means, means for detecting the magnitude of a load connected to said output terminal, and means for changing the inductance of said inductive means in accordance with an output of said second detecting means.
The other objects, features and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings through which like numerals designate like elements