Minolta Di620, Manual, Page: 77 / 466

M-58
1155SBM1104A
11-4. ATDC Sensor
During operation, the ATDC sensor detects the T/C ratio (toner-to-carrier ratio) in the
developer mixing chamber. If the detected ratio is below the target level of 4%, the
copier will add toner. Note that the reference T/C ratio of 4% (at setup) produces an
ATDC sensor output of 2.5V.
The copier can be set so that it disables copy operation if the T/C ratio drops below
3.0% while a Toner Empty condition exists. (This disable feature may be set ON or
OFF by a Service Choice function.) If copying has been disabled in this way, it will
automatically be re-enabled when the Toner Empty condition is cleared.
Opening and then closing the upper door while the copier Toner Empty condition
exists will cause the copier to begin toner replenishing. (Entry of toner into the sub-
hopper immediately clears the Toner Empty condition. Toner replenishing continues
until the toner amount reaches the target level.)
<Automatic Adjustment of ATDC Sensor>
The ATDC sensor is adjusted automatically when F8 mode is run.
* Running F8 mode after starter has been replaced.
When toner agitation is completed (after the START key is pressed), the CPU
reads the value output by the ATDC sensor, then adjusts the sensor's gain so that
the sensor output value becomes 2.5V.
CONTROLLED
PART
CONTROL
SIGNAL
REFERENCE
T/C RATIO
STANDARD
OUTPUT VOLTAGE
WIRING
DIAGRAM
UN4 PJ8A-10B 4.5 (%) 2.32 (V) D-4
In general, F8 mode should be executed only when the starter is replaced. Run-
ning F8 mode at other times may result in an incorrect setting for the reference T/
C ratio. If the ATDC setting has been cleared as a result of RAM-board replace-
ment, use the Service Mode's Element Data function to set the ATDC value back
to the setting it had just prior to the board replacement.
NOTE