HP CP6015dn Service Manual - Page 173

The low-voltage power supply converts the AC power into three DC voltages, which are then subdivided, as described in the following table. Table 5-8 Converted DC voltages Main DC voltage Sub-voltage Behavior +24 V +24VA Constantly supplied +24VB Interrupted when the front door or right door is opened Stopped during Sleep (powersave) mode +24VC Stopped during Sleep (powersave) mode +5 V +5VA Stopped during Sleep (powersave) mode +5VB Interrupted when the front door or right door is opened Stopped during Sleep (powersave) mode +3.3 V none Constantly supplied Overcurrent/overvoltage protection The low-voltage power supply stops supplying the DC voltage to the product components whenever it detects excessive current or abnormal voltage from the power source. Safety For personal safety, the low-voltage power supply interrupts power to the fuser, the high-voltage power supply, and the motors whenever the front door or right door is opened. Voltage detection The DC controller monitors the input voltage from the power source so it can control the voltage to the fuser. If the input voltage is out of range, the DC controller notifies the formatter that the low-voltage power supply has failed. Sleep (powersave) mode Sleep mode conserves energy by stopping the power to several components when the product is idle. If the DC controller detects voltage that is too high when the product is in Sleep mode, it determines that the low-voltage power supply has failed, and it notifies the formatter. High-voltage power supply The high-voltage power supply delivers the high-voltage biases to the following components that are used to transfer toner during the image-formation process: ● Primary-charging roller ● Developing roller ENWW Engine-control system 131