Bruker NMR AV4 BSMS System, User Manual

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VPSB-DC and VPSB-DC-E
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15 VPSB-DC and VPSB-DC-E
15.1 Introduction
The VPSB-DC (Variable Power Supply Board DC variant) is the successor of the Variable
Power Supply Board VPSB. In contrast to the VPSB, the new VPSB-DC uses only backplane
power and has no mains supply connector anymore. Also the control communication directly
goes through the backplane and is not looped through the Sensor and Pneumatic Board SPB
anymore.
The VPSB-DC is available in an extended version VPSB-DC-E, which includes a booster
functionality for WB Systems that can supply more output power to one of the two heater
power outputs.
The VPSB-DC integrates two mostly independent variable power sources in one 6TE 19“
unit, the VPSB-DC-E comes in a 12TE 19“ unit.
Low level hardware functions (e.g. safety circuits and A/D converter control) are implemented
directly on the VPBS-DC(-E), whereas higher level functions such as output power control
and read-out of the power monitoring are done by software running on the ELCB.
A two-stage watchdog system and a smart probe heater impedance meter circuit ensure safe
operation in case of serious malfunction.
The VPSB-DC(-E) has interfaces for connecting digital accessory sensors (temperature,
digital level sensors).
15.2 Configurations
There are two board variant available.
One VPSB-DC has two power outputs that allow to set-up two controlled temperature
channels.
One VPSB-DC-E has two power outputs that allow to set-up two controlled temperature
channels. The first channel can deliver more output power (booster functionality), if it is used
with a recent VT adapter. The overlying software will check that the VT adapter supports
booster operation, which is given if the device revision is at least 1. The figure below shows
how the VT adapter device revision can be checked on the AV4 BSMS service web variable
temperature control BFB overview.