Gp 5.19 Power Supply - Xerox DocuPrint N2025 Service Manual

GP 5.19 Power Supply

LVPS (Low Voltage Power Supply) Figure 1
The N2025/N2825 LVPS is a separately-excited, feedforward switching regulator. The LVPS
produces +24 VDC, +5 VDC, and +5 VDC (B) voltages from AC power. +5 VDC (B) is labeled
as 5V-LD in the printer wiring diagrams.
The LVPS has the following three protections.
-Short-circuit protection (over current protection)
When the 5VDC or 24VCD supply circuit is short-circuited, and an excessive current begins to
flow in the circuit, all DC supplies are shut down. To reset this short-circuit protection, switch off
printer power, remove the cause, then switch on printer power two or three minutes after turn-
ing the power off.
-Open-circuit protection (overvoltage protection)
When the 5VDC or 24VDC supply circuit is open or the connector is disconnected, the output
voltage of the circuit begins to decrease after about 1 minute and the output is stopped. To
reset this open-circuit protection, switch off the printer power, reconnect the connector or repair
the open circuit, then switch on printer power about five minutes after the power off.
-Low-voltage protection
When the voltage of the 24VDC supply circuit becomes 15 VDC or lower, the output voltage of
the 24VDC supply circuit begins to decrease and the output is stopped.
HVPS (High Voltage Power Supply) Figure 1
The HVPS produces the high voltages applied to the BCR, BTR, DB, and DTS from +24 VDC
supplied by the LVPS under the control of the Print Engine Controller PWB.
Figure 1 HVPS/LVPS Locations
The HVPS has an overcurrent protection. If an excessive current begins to flow in any of the
high voltage output circuits, all high voltages are shut down. To reset the protection circuit after
an overcurrent shutdown, switch off the printer power, remove the cause, then switch on the
printer power again.
Initial Issue General Procedures / Information
02/2000
GP 5.19
DocuPrint N2025/N2825 6-75