| 摘要 |
When an image forming apparatus shifts to a power saving mode, a controller unit further reduces power consumption by switching AC current on/off every predetermined amount of time. When AC current input from a commercial AC power supply is turned off, a DC voltage generating circuit normally can no longer supply a DC voltage, rendering the controller unit unable to operate. Accordingly, the controller unit operates using a charge accumulated in a smoothing capacitor while the AC current is not being supplied. An AC cutting circuit is switched on before a both-end voltage at the smoothing capacitor drops below a lower limit of operation voltage of the DC voltage generating circuit, and the smoothing capacitor is recharged. |
| 主权项 |
1. Electric equipment having a normal power supply mode and a power saving mode that consumes less power than the normal power supply mode, the equipment comprising:
an AC cutting circuit, connected serially to a power supply line through which AC current is input, configured to turn the supply of the AC current on and off; a rectifying and smoothing circuit configured to rectify the AC current and smoothes the AC current using a capacitor; a DC voltage generating circuit, connected to the rectifying and smoothing circuit, configured to generate a DC voltage; and a controller, operating under the DC voltage generated by the DC voltage generating circuit, configured to cause the AC cutting circuit to turn the supply of the AC current off when the electric equipment shifts to the power saving mode, and then cause the AC cutting circuit to turn the supply of the AC current on every predetermined amount of time in order to charge the capacitor. |
