Power supply apparatus, printer, and control method

A printer comprising:

• a print head, and
• a power supply apparatus, wherein the power supply apparatus includes:
• a power source circuit configured to supply electric power to the print head,
• a capacitor connected to a power supply line extending from the power source circuit to the print head and configured to supply electric power to the print head,
• a charge circuit configured to charge the capacitor by supplying a current that is powered by the electric power supplied from the power source circuit,
• a detection circuit configured to detect a voltage value of the capacitor, and
• a controller configured to, in a case where the detected voltage value of the capacitor reaches a first threshold value, control the charge circuit to change a current value of the current of the charge circuit from a first current value to a second current value that is smaller than the first current value,
• wherein the first current value is supplied before the detected voltage value reaches the first threshold value,
• wherein the second current value is greater than zero, and
• wherein, after the detected voltage value of the capacitor reaches the first threshold value, the controller is further configured to
• continually determine, while the second current value is supplied to the capacitor, whether the detected voltage value of the capacitor is smaller than a second threshold value that is smaller than the first threshold value, and
• cause a discharge of the capacitor in a case where the controller determines that the detected voltage value of the capacitor is smaller than the second threshold value.

A method for controlling a power supply apparatus having a power source circuit configured to supply electric power to an electric load, a capacitor connected to a power supply line extending from the power source circuit to the electric load and configured to supply electric power to the electric load, and a charge circuit configured to charge the capacitor by supplying a current that is powered by the electric power supplied from the power source circuit, the method comprising:

• detecting a voltage value of the capacitor;
• determining whether the voltage value of the capacitor has reached a first threshold value;
• in a case where the voltage value of the capacitor has reached the first threshold value, controlling the charge circuit to change a current value of a current of the charge circuit from a first current value to a second current value that is smaller than the first current value, wherein the first current value is supplied before the detected voltage value reaches the first threshold value, and wherein the second current value is greater than zero;
• and
• the detected voltage value of the capacitor reaches the first threshold value,
• continually determining, while the second current value is supplied to the capacitor, whether the detected voltage value of the capacitor is smaller than a second threshold value that is smaller than the first threshold value, and
• causing a discharge of the capacitor in a case where the detected voltage value of the capacitor is smaller than the second threshold value.