**METHOD AND APPARATUS FOR CONTROLLING SWITCHING POWER SOURCE**

PURPOSE: To eliminate a reduction in an input voltage controllable range due to high frequency by fixing a pulse frequency and a pulse width, and altering the number of pluses included for a predetermined time.

CONSTITUTION: N is calculated by using a logic circuit. That is, an output voltage and a reference output voltage are inputted to a differential amplifier to obtain a differential voltage between both, it is input to a V/f converter to be converted into a frequency as a gate to obtain the N by counting clocks 1MHz. In this case, since the converter receives only a positive voltage, an input is so switched that the output of a differential amplifier always becomes positive by using the output of a digital comparator. Actually, in order to calculate the N, a binary counter output is shifted by 6 digits to obtain it. A gate 2 pulses are formed by a 1/(N+1) frequency divider and a gate 1 pulse as a clock pulse by using the N output, and further inverted to form a gate 3 pulse.

Murasato, Michihisa

Yamashita, Satoshi

Yamamoto, Takaaki

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**H02M3/155***; (IPC1-7): H02M3/155; H02M3/28*

**H02M3/28**