512/17704/011 X-Ray/Pmt Control Pcb - Micromeritics SediGraph III 5120 Service Manual

Card Cage and PCBs
• 2X Logic level inputs (for cell limit switches). There are two logic level (+5VDC)
inputs Up/Down. These are active Low signals. A Low signal (from either switch) stops
cell movement in the associated direction. There is also an LED for each direction. The
LED is lit when the associated switch is active.
• Status LEDs: for motors, heaters and limit switches
• Board ID EEPROM with I
identification and configuration information.
• MICBus interface to connect the PCB with the rest of the instrument.
• Surface mount design, except for thru-hole connectors.

512/17704/011 X-Ray/PMT Control PCB

This board will function the same as the 510/17720/01 PCB with the exception that all pots
have been replaced with 12 bit DACs. The X-ray/PMT control PCB has the following
features.
• No pots.
• A/D channels to monitor key voltages or current for troubleshooting. The voltages or
current that can be monitored in the Service test mode include:
• X-ray high voltage
• X-ray current
• Photo-Multiplier tube voltage
• X-ray filament supply
• Board ID EEPROM with I
identification and configuration information.
• Surface mount design, except for thru-hole connectors, and specialized components.
• X-ray filament supply, a 5VDC switching regulator located on this PCB with the
capability of being set for 8VDC.
• X-ray tube interface, DAC controlled at 13,600VDC and monitored as 0 to 5VDC
corresponding to 1 to 15KVDC.
• PM Tube interface, DAC controlled at a voltage unique to a calibrated Photo-multiplier
tubes voltage and monitored as 0 to 7.5VDC corresponding to 0 to 1500VDC.
2-14
2
C interface, this EEPROM is used to hold the board
2
C interface. This EEPROM is used to hold the board
SediGraph III 5120 Service
Mar 2010