Power supply apparatus, switching power supply apparatus, and image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorAtsushi Asayama
Life of this patent
Estimating the term…
Abstract
A power source control chip which is a high voltage controlling portion is added to an ASIC for sequence control constituting a sequence control unit. A PWM signal is sent from the high voltage controlling portion to a high voltage producing portion constituting a high voltage unit, and an output detection signal is sent from the high voltage producing portion to the high voltage controlling portion, thereby effecting feedback control. At that time, a modulated wave PWM/detection signal amplitude-modulated with the PWM signal as a carrier wave and with the output detection signal as a modulating wave is produced and is transmitted onto a signal line, whereby the number of signal lines can be decreased.
Claims14
A power supply apparatus comprising:
- a sequence control unit to which a power source control chip is added;
- output producing means for producing an output conforming to a PWM signal from said power source control chip, and feeding back an output detection signal to said power source control chip;
- and
- a signal line for connecting said power source control chip and said output producing means together,
- wherein a modulated wave amplitude-modulated with said PWM signal as a carrier wave and with said output detection signal as a modulating wave is transmitted to said signal line.
A power supply apparatus comprising:
- an image processing unit to which a power source control chip is added;
- output producing means for producing an output conforming to a PWM signal from said power source control chip, and feeding back an output detection signal to said power source control chip;
- and
- a signal line for connecting said power source control chip and said output producing means together,
- wherein a modulated wave amplitude-modulated with said PWM signal as a carrier wave and with said output detection signal as a modulating wave is transmitted to said signal line.
A switching power supply apparatus comprising:
- voltage producing means for producing a predetermined voltage;
- and
- controlling means for controlling the voltage by a digital circuit,
- wherein said voltage producing means has a transformer, rectifying and smoothing means for rectifying and smoothing an output of said transformer, driving means for driving said transformer, detecting means for detecting an output obtained by said rectifying and smoothing means, and modulating means for modulating with a detection output detected by said detecting means as a modulating wave, and
- wherein said controlling means has demodulating means for demodulating the detection output from a signal modulated by said modulating means, sample hold means for sampling and holding said demodulated detection output, A/D converting means for converting an output of said sample hold means into a digital signal, comparing means for comparing an output of said A/D converting means with an output target value, a counter adapted to be operated in conformity with an output of said comparing means, and PWM signal producing means for producing a PWM signal for driving said driving means.
Dependencies are inferred from the claim text.