Dr.X Works BH1-L User manual

Bipolar current supply
BH1-L
product manual
version 1.0
Dr.X Works BV
Engelsbergenstraat 18
5616JC Eindhoven
The Netherlands
Phone: [phone]
www.drx-works.nl
[e-mail]

Contents
1 Introduction 4
2 Installation 5
2.1 Unpacking and inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Connections and controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 powerrequirements................................ 5
2.4 Cooling ...................................... 5
3 Operation 7
3.1 Programming................................... 7
4 Technical specification 9
4.1 Electrical ..................................... 9
4.2 Mechanical .................................... 9
5 Environmental 10
6 Maintenance 11
7 Safety 12
8 Warranty 13
9 Mechanical outline 14
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1. Introduction
The Bipolar Current Source was originally intended for use with the focussing coils and
steering coils in the beam-line of the 100 kV ultrafast Electron Diffraction set-up, the
PMX setup sold by DrX Works BV. The goal of the design was to develop an easy to use,
low noise, and stable current source with smooth zero passage for driving inductive loads,
programmable over USB. The Current Supply is switchable from +/- 1 A max (for steering
coils) to +/- 2A max. (for focussing coils).
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2. Installation
2.1 Unpacking and inspection
This instrument has been thoroughly inspected and tested prior to packing and is ready
for operation. After careful unpacking, inspect for shipping damage before attempting to
operate. If any indication of damage is found, file an immediate claim with the responsible
transport service.
2.2 Connections and controls
The output connectors used are Speakon connectors indicated as A&B and B. Matching
connectors are provided in the package. When a set of steering coils (X & Y) is used, both
coils can be connected to one output (A&B) on the rear of the device. When two focusing
coils are used they should be connected to the two outputs separately. For optimal noise
performance, a shielded cable should be used, with the shield connected to -1 and -2 (see
Fig. 2.1).
2.3 power requirements
The current source operates on single phase AC mains power from 100 V to 240V with a
frequency between 47 and 63 Hz without any need for range selection. The primary fuses
are 4AT.
2.4 Cooling
The power devices used within the power supply are maintained within their operating
temperature range by means of internal heat sink assemblies cooled by a single fan. If the
power supply is located within a confined space, care must be taken that the temperature
of the air immediately surrounding the power supply, does not rise above 30◦C.
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2.4. Cooling
Figure 2.1: Connections
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3. Operation
After installation into 19”-rack or other, connect mains cable to the back panel. Turn on
the power switch, after which, both current displays will light up, indicating 0.0 A. By
pushing the ON button the output will switch on, if the device is in manual mode the
current can be set with the corresponding potentiometer. The current is set to zero when
the dial reads 500. When the temperature of the heat sinks in the current supply exceeds
67◦C the device will turn off and the OFF LED will light up. The ON button resets the
over-temperature shutdown.
3.1 Programming
When the current source is going to be used in USB mode, a virtual serial port has to
be installed: http://www.ftdichip.com/ The WindowsTM device manager will show what
port number is assigned to the device. To test the configuration free software is avail-
able at Sourceforge.com http://sourceforge.net/projects/realterm/files/. The address of
the DAC’s installed in the power source is : 0x18 and 0x19 The busnumber of the DAC is
0x01. The virtual serial port has to be configured as follows:
Baud rate 57600
Parity none
Data bits 8
Stop bits 1
Hardware flow control RTS/CTS
When the remote control is going to be used in USB mode, a virtual serial port has
to be installed: http://www.ftdichip.com/ The windows device manager will show what
portnumber is assigned to the remote control. To test the configuration free software
is available at Sourceforge.com: http://sourceforge.net/projects/realterm/files/. To set a
value to the DAC (eg. FFF) use the following commands:
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3.1. Programming
Ascii
“G” Set busnummer
“1” to “1”
“S” Start I2C = ”S” */
“1” 1st nibble adres
“8” 2nd nibble adres
“3” 1st nibble control byte
“2” 2nd nibble control byte
“F” 1th nibble data
“F” 2th nibble data
“F” 3th nibble data
“F” 4th nibble data
“P” stop I2C
The example above is to enable the output of channel A. Once enabled the data can
be written by using “31” as the control byte. The address for channel B = 0x1A. NOTE:
Data = FFFF = 0 Amp and Data = 0000 = Max. Current.
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4. Technical specification
4.1 Electrical
The Current Supply is mounted in an EMC enclosure. Typical performance, measured
fully warmed-up (30 min.) are given in the table below:
Imax ±2 A
Vmax 6V
Full scale error 0.7% FSR
Stability (USB controlled) <2x10−5/◦C
Stability (potmeter controlled) <5x10−5/◦C
Non linearity (DNL) −0.5.. + 0.6 LSB
Resolution 15 bits
Settling time (resistive load) 20ms
Settling time (steering and focusing coil) 30ms
USB optically isolated
4.2 Mechanical
Dimensions (LHW) 19” x 2U x 500mm
Weight ca. 7kg
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5. Environmental
Operating temperature range 15 to 25◦C ambient, however temperature fluctuations should
be kept as small as possible to prevent drifting. The Bipolar current supplyshould be
operated in a clean environment. On no account must the Bipolar current supplybe exposed
to water ingress.
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