Description Of Operation - Toshiba e-STUDIO520 Service Manual
Multifunctional digital systems
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Also See for e-STUDIO520:
- Service handbook (650 pages) ,
- User functions manual (202 pages) ,
- Network administration manual (124 pages)
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10.4.2
Description of operation
The function and operation of each signal are as follows.
On-off signal (HVTM-0A, HVDAC-0A, HVDDC-0A, HVTT-0A, HVTBB-0A):
These signals are the on-off signals of each bias output to the main charger (main charger wire and
grid), developer bias (AC/DC), transfer belt power supply roller, and transfer belt cleaning brush. When
these signals move to a low level, the generating circuit of each bias on the high-voltage transformer
becomes on status, thus the current or voltage is output.
Reference voltage (Vctr) (HVMVR-1A, HVDVR-1A, HVTVR-1A):
These analog voltages are the reference for each output of the main charger grid, developer bias (DC)
and transfer belt power supply roller. Each output of the high-voltage transformer can be changed lin-
early by changing these reference voltages.
The output procedure of the reference voltages is shown below.
•
The adjusted values of the main charger bias, developer bias and transfer bias in the NVRAM are
output to the ASIC.
p
•
The data of the reference voltage is output from the ASIC to the D/A converter.
p
•
Digital-to-analog conversion at the D/A converter
p
•
The reference voltage (Vctr) of each bias is output to the high-voltage transformer.
p
•
The high-voltage transformer generates the output current or output voltage proportionate to the ref-
erence voltage.
* The reference voltage (Vctr) can be adjusted in the Adjustment Mode (05).
* The output of the transfer belt cleaning brush was adjusted at a constant value when the high-volt-
age transformer was shipped from the factory, and this adjusted value has been fixed since then.
Developer AC bias generating clock (HVTAC-0A):
This clock signal is a reference for the AC component of the developer bias.
Leak detection signal (HVTER-0):
This signal detects the abnormality (leakage) of the high-voltage transformer output. When the abnor-
mality is detected, the signal moves to a low level.
March 2005 © TOSHIBA TEC
e-STUDIO520/600/720/850 PROCESS RELATED SECTION
10 - 5
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