5. MAINTENANCE, ADJUSTMENTS AND CALIBRATION
Page 137
© 2007 DH Instruments, a Fluke Company
5.9.1.2
POWER SUPPLIES
+12 V DC (± 2 %) @ 3.3 Amps: For internal and external solenoid valve
actuation, thermal pressure control unit (TPCU), servo-controlled valve stepping
motor supply.
+5 V DC (± 1 %) @ 3.0 Amps; + 15 V DC (± 3 %) @ 2.0 Amps; -15 V DC (± 3 %)
@ 0.35 Amps: For the supply of the micro board and driver board electronics.
Internal power supply fuse not replaceable by operator: 2A, 250 V (UV 440-2
power supply). 3.15A, 250 V (NFS40-7612 power supply).
5.9.1.3
DRIVER BOARD
The driver board is controlled by the mini micro board (see Section 5.9.1.4).
It supports:
•
12 V drivers for internal and external solenoid valve actuation
•
Frequency counters (2) for Q-RPTs (see Section 5.9.2.2)
•
On-board barometer power and output (see Section 5.9.1.5)
•
Supply pressure transducer power and output (see Section 5.9.2.1)
•
Utility sensor (if present) power and output (see Section 5.9.2.2)
•
Power to the electrical system cooling fan
•
Power to thermal pressure control unit (TPCU) (see Section 5.9.2.11)
•
Power to and control of servo-valve stepping motors (see Section 5.9.2.9)
•
Remote
[ENT]
•
Keypad and display
•
Beeper
5.9.1.4
MINI MICRO BOARD
The micro board supports a Motorola 68302 micro-controller, EPROM,
EEPROM, 128k x 16 bit NVRAM, 8 Mbit flash memory; RS-232 and IEEE-488.2
communications; keypad and display control. An I/O port controls other ports
and devices in PPCH-G.
5.9.1.5
ON-BOARD BAROMETER
The on-board barometer supports a board mounted, barometric range,
micromachined silicon sensor and an ambient temperature sensor. The
barometer readings are used for dynamic atmospheric pressure compensation
when measuring gauge pressure (see Section 3.2.4). The temperature sensor is
used for temperature compensation of the barometric sensor.
