Epson Stylus Photo RX700 - Pressure Pump Mechanism; Pressure Pump Motor; Pressure Sensor

EPSON Stylus Photo RX700 Revision A
Operating Principles Mechanism Operating Principles 38
2.2.9 Pressure Pump Mechanism
2.2.9.1 Pressure Pump Motor
 Drive system
2.2.9.2 Pressure Sensor
 Function: Detection of pressurization / pressure release
 Detector specifications
Figure 2-29. Pressure Pump Assy Mechanism
Item Specifications
Type DC brush motor
Voltage 42 V (DC voltage) ±5% (voltage applied to the driver)
Basic
characteristics
Armature resistance 64.7Ω ±15%
Inductance 37.6mH ±25%
Rotor inertia 3.97 gcm
2
Drive system PWM system, constant-current chopping system
Operation Current
Direction of Motor Rotation
(as viewed from the output side)
Pressure
OUT_A → OUT_B CW
Pressure release
OUT_A → OUT_B CCW
PWM driving
method
The PWM fundamental period resolution is 24 MHz (= 41.7 nsec), which is taken as
one count. The output time is the ON time, while the remaining time is OFF time.
During the OFF time in PWM driving mode, the slow-decay mode is used with both
the transistors on the sink side turned ON (synchronous rectification is enabled in the
active mode). Unless specified, the motor is stopped by a short brake (duty=0).
Current chopping
method
The slow-decay mode (chopping OFF time of 50 µsec.) is always used during
current chopping for current control. The slow-decay mode is such that the blanking
time is 6
µsec. and both the transistors on the sink side are turned ON during
chopping OFF in PWM driving mode. (Synchronous rectification is enabled in the
active mode.) The upper limit current value is ± 0.63[A] ± 8%.
Item Specifications
Detection method Photo-electric conversion system (transmissive-type photo-interrupter)
Model GP2S24C J000F (SHARP)
Voltage 3.3 V ± 5%
Detected Condition Detector Output Remarks
Pressurized
H Light transmitted
Pressure released
L Light intercepted
Pump HP Sensor
Pressure Sensor
Pressure Pump Motor
Pressure Pump
Relief Valve
CW rotation
CCW rotation
The valve is closed, so
that the compressed
air is supplied through
the I/C Holder to the
Printhead.
When the gear turns
counterclockwise, the
lever pushes up the valve
to release the compressed
air from the chamber.