Atdc Sensor - Minolta EP1080 Service Manual

7-1. ATDC Sensor

ATDC Sensor UN3 installed on the underside of the Developer Mixing
Chamber detects the varying toner-to-carrier ratio of the developer which
flows over it in the Chamber. The copier CPU compares the detected ratio
with the ratio set by the ATDC Detection Level Mode (Tech. Rep. Choice
SCH-90) to control toner replenishment.
Set T/C (%) ATDC Output Voltage (V)
4.0 2.725
4.5 2.6125
5.0 2.5
5.5 2.3875
6.0 2.275
6.5 2.1625
Toner is replenished for 5 seconds (the Toner Bottle is turned one turn,
which is equivalent to a run of 2 copy cycles) for each Toner Replenishing
signal.
If the toner-to-carrier ratio becomes lower than 2%, the copier inhibits the
initiation of a new copy cycle (this feature can be enabled or disabled by a
Tech. Rep. Choice mode). When a ratio of 2.5% or more is recovered as a
result of Auxiliary Toner Replenishing, the copier permits the initiation of a
new copy cycle.
If the Front Door is swung open and closed with a T/C ratio of less than
2.5%, the copier initiates an Auxiliary Toner Replenishing sequence. (It
stops the sequence as soon as a T/C ratio of 3% is reached.)
ATDC Sensor Automatic Adjustment
An automatic adjustment of the ATDC Sensor is made in the F8 Test
Mode operation and when a new Imaging Unit is installed in the copier.
When a New Imaging Unit is Installed in the Copier:
*
Following the execution of the starter setup mode upon power-up, the
copier CPU reads the output value of the ATDC Sensor and establishes
the reading as the reference value.
When F8 is Run after Starter Has Been Changed:
*
Following the execution of the starter setup mode upon pressing of the
Start Key, the copier CPU reads the output value of the ATDC Sensor
and establishes the reading as the reference value.
NOTE: If an F8 operation is run at a time when the starter has not been
changed, it can result in a wrong T/C reference value being set by
the copier. Avoid casual use of F8.
If the setting value has been cleared because of the RAM Board
being replaced, however, enter the ATDC control value before the
replacement using the Zoom Up/Down Keys in the F8 operation
(without pressing the Start Key).
M-17