Low-capacity power supply and image forming apparatus

摘要

A low-capacity power supply is described in which an input capacitance may be adjusted. In one example, input capacitors may be located between an AC power supply and a rectifier. Additional adjustment capacitors may be located on one or more input lines to the rectifier. The adjustment capacitors may be added in series to at least one of the input capacitors to decrease the input capacitance of the rectifier. In this example, the power provided downstream of the rectifier may be adjusted to increased or reduced as needed. In other examples, additional switches are provided for the input capacitors to selectively add their capacitance to or remove their capacitance from the input of the rectifier.

主权项

1. A low-capacity power supply connectable to an AC power supply having first and second terminals, the low-capacity power supply comprising:
a first capacitor electrically connected to the first terminal of the AC power supply; a second capacitor electrically connected the second terminal of the AC power supply; at least one adjustment capacitor electrically connected to the first capacitor in series; at least one switching circuit electrically connected in parallel with any one of the first capacitor and the adjustment capacitor; a rectifier provided at a stage following the first capacitor with respect to the AC power supply; a smoothing circuit electrically connected to receive an output of the rectifier, the smoothing circuit configured to smooth the output of the rectifier; a detecting circuit configured to detect a voltage level of an output of the smoothing circuit; and a controller configured to control an operation of the switch circuit, wherein the rectifier is a full-wave rectifier with one input being downstream from the first capacitor and a second input being downstream from the second capacitor, and wherein the controller is configured to control the operation of the switch circuit in response to a detected voltage level from the detecting circuit.