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

EPSON Stylus Photo RX700

2.2.9 Pressure Pump Mechanism

2.2.9.1 Pressure Pump Motor

Item
Type DC brush motor
Voltage 42 V (DC voltage) ±5% (voltage applied to the driver)
Armature resistance 64.7Ω ±15%
Basic
Inductance 37.6mH ±25%
characteristics
Rotor inertia 3.97 gcm
Drive system PWM system, constant-current chopping system
Operation Current
→
Pressure OUT_A OUT_B
→
Pressure release
OUT_A OUT_B
Drive system
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.
PWM driving
During the OFF time in PWM driving mode, the slow-decay mode is used with both
method
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).
The slow-decay mode (chopping OFF time of 50
current chopping for current control. The slow-decay mode is such that the blanking
Current chopping µ
time is 6 sec. and both the transistors on the sink side are turned ON during
method
chopping OFF in PWM driving mode. (Synchronous rectification is enabled in the
active mode.) The upper limit current value is ± 0.63[A] ± 8%.

2.2.9.2 Pressure Sensor

Function: Detection of pressurization / pressure release
Detector specifications
Item
Detection method Photo-electric conversion system (transmissive-type photo-interrupter)
Model GP2S24C J000F (SHARP)
Voltage 3.3 V ± 5%
Detected Condition
Pressurized
Pressure released
Operating Principles
Specifications
2
Direction of Motor Rotation
(as viewed from the output side)
CW
CCW
µ
sec.) is always used during
Specifications
Detector Output Remarks
H Light transmitted
L Light intercepted
Mechanism Operating Principles
Pressure Sensor
Relief Valve
CW rotation
The valve is closed, so
that the compressed
air is supplied through
the I/C Holder to the
Printhead.
CCW rotation
When the gear turns
counterclockwise, the
lever pushes up the valve
to release the compressed
air from the chamber.
Figure 2-29. Pressure Pump Assy Mechanism
Revision A
Pressure Pump Motor
Pressure Pump
Pump HP Sensor
38