Bruker BioSpin BLAH2000-I E C, Operating & Service Manual

Page: 25 / 48

Operating & Service Manual Version 001 BRUKER BIOSPIN 25 (47)
Theory of Operation
RF Coupler
The bi-directional coupler provides an approximate 1V peak DC signal for full
2000W forward power and also a peak DC signal for reflected power level.
Forward and reflected signals are analyzed by the BLA control board for
monitoring and protection of the RF power output.
The coupler provides also two RF signals wich are the image of the forward and
reflected RF power.
These signals can achieve -4dBm for full 2000W power and are wired to the front
panel on POWER FORWARD and POWER REFLECTED connectors.
BLA Control Board 5.2.2
The BLA Control Board has 3 main functions:
1. Conditions the input gating (BLNK TEST) signal and delivers it to the above
mentioned RF Paths.
2. Allows Ethernet communication with the workstation.
3. Monitor the output characteristics of the amplifier thanks to the DC peak
detection of the bi-directional coupler.
Only for amplifier test : The Ethernet Controller can read all the information
given by the control board as described before, read information about forward
and reflected power, information of identifications of the amplifier (Bruker
Identification System = BIS). It also can minimize absolute ratings for pulse width,
duty cycle and peak power limitations.
Warning : the operating of the Ethernet Link requires a Spectrometer
Management Sofware such as TOPSPIN.
Configuration, diagnosis and servicing access to the amplifier relies on http. See
more information in
"Servicing the BLA" on page 27 .
The monitoring circuitry is also useful to process the detection information and
protect the amplifier from overstress in peak power, average power versus duty
cycle and pulse width, so as excess of reflected power.
The control board also monitors the RF Path heatsink temperature to protect
against thermal overstress.
Information from supplies and fan status board are also analyzed by the control
board.
If one of the above overstresses, faults on power supplies or fans appears, the
gating signal is disabled, and the status led board on the front panel displays the
fault.