Power supply apparatus, control apparatus, and program therefor

A control apparatus that controls a DC/DC converter including:

• an inductor to which an input voltage is applied,
• a switching element that switches a current flowing to the inductor on and off so as to cause an induced voltage to be generated, and
• an electrolytic capacitor that smoothes a voltage responsive to the induced voltage and outputs the voltage to a load,
• wherein the control apparatus
• outputs, to the switching element, a second control signal obtained by superimposing an estimation signal on a first control signal, wherein the first control signal performs on and off control on the switching element at a switching frequency and changes a duty cycle so that an output voltage becomes a predetermined voltage, and the estimation signal has an estimation-purpose frequency lower than the switching frequency,
• detects the output voltage, the output voltage being based on switching performed by the switching element, the switching being controlled by the second control signal, and
• estimates capacitance of the electrolytic capacitor by using the detected output voltage, the duty cycle of the first control signal, and a frequency component of the estimation signal contained in the detected output voltage.

A computer-readable and non-transitory storage medium storing a program that controls a DC/DC converter including:

• an inductor to which an input voltage is applied,
• a switching element that switches a current flowing to the inductor on and off so as to cause an induced voltage to be generated, and
• an electrolytic capacitor that smoothes a voltage responsive to the induced voltage and outputs the voltage to a load,
• wherein the computer program causes a control apparatus to execute an operation, the operation comprising:
• outputting, to the switching element, a second control signal obtained by superimposing an estimation signal on a first control signal, wherein the first control signal performs on and off control on the switching element at a switching frequency and changes a duty cycle so that an output voltage becomes a predetermined voltage, and the estimation signal has an estimation-purpose frequency lower than the switching frequency;
• detecting the output voltage, the output voltage being based on switching performed by the switching element, the switching being controlled by the second control signal;
• and
• estimating capacitance of the electrolytic capacitor by using the detected output voltage, the duty cycle of the first control signal, and a frequency component of the estimation signal contained in the detected output voltage.