Spellman MPS Series Setup guide

Issue 2 Page 1 of 16
High Voltage Power Supply
MPS 20W 1kV to 20kV SERIES
SAFETY AND INSTALLATION
INSTRUCTIONS
Document number: 80552-4
Issue
1
2
Date
16/06/09
18/06/09
Issuing Authority
I-1518
5732U
Checked
Approved
Spellman High Voltage Electronics Limited
Company Confidential
This document must not be copied or distributed without express permission from Spellman High Voltage
Electronics Limited
Tel : [phone]
Fax : [phone]
e-mail : [e-mail]
Broomers Park, Broomers Hill Lane
Pulborough, W. Sussex, RH20 2RY

Issue 2 Page 2 of 16
CHANGE HISTORY
Section
Reason for Change
Issue
All
Original
1
5 – table 1
Output impedances changed to 2k2.
2

Issue 2 Page 3 of 16
SAFETY
DANGER
HIGH VOLTAGE
RISK OF ELECTROCUTION
Observe extreme caution when working with this equipment
High voltage power supplies must always be
connected to a protective earth
Do not touch connections unless equipment is
turned off and the capacitance of both the load
and power supply are grounded
Allow adequate time for discharge of internal
capacitance of the power supply
Do not ground yourself or work under wet or
damp conditions
Servicing Safety
When maintenance of equipment fitted with this
power supply requires removing the equipment
cover with the power on, this should only be done
by qualified personnel aware of the hazards
This power supply has no user serviceable parts.
Return to supplier for servicing

Issue 2 Page 4 of 16
1 Unit Description
The MPS series of high voltage dc-dc converters is a range of units designed to produce a
high quality dc output for a very wide range of instrumentation and analytical applications. The
combination of linear and switch mode power conversion techniques provide low noise
and high efficiency. The unit also offers excellent ripple and stability specification. The
standard unit incorporates the ability to pre set the output or control it over the full output
range with good linearity performance. A differential input is also available to eliminate
system noise problems.
The units are designed for operation from a 24V dc input and will supply up to 20W of output
power. The HV output is via a 1m long un-terminated URM76 LSF screened cable. The
signal and power inputs and outputs are via a 15 way male ‘D’ connector but the pinout of
this connector varies according to the model type.
Three factory configured options are available :-
/VCC : Voltage and Current Control option, allowing current control of the unit.
/DCC: Digital Control Card option with digital control and monitoring (factory
configured to either RS232 or RS485 interface standards, 9600 baud).
The part number for the unit describes its main characteristics :-
MPS 20 N 20 / 24 / DCC
Model type
Max o/p kV
Polarity
Max o/p
power (w)
Input voltage
Options

Issue 2 Page 5 of 16
2. Safety
The HV output of the unit is hazardous and the conditions of this manual must be complied
with to maintain safety. The unit is contained in an earthed case with a screened HV
output cable and the HV output cable must be terminated safely before the unit is
operated. This unit must be sourced with a double insulated 24 V dc supply.
The unit shall be properly bonded to the main protective earthing termination in the end
product.
The unit has been evaluated for use in a Pollution Degree 2, Installation Category II
environment.
Consideration should be given to conducting the following tests with the unit installed in
the end product:
a. Dielectric Voltage Withstand Test, between live parts of the unit and the
end product chassis.
b. Permissible Limits Tests with the unit installed in the end product.
c. Temperatures on power electronic components, transformer windings and
accessible surfaces.
The case performs the function of heat sink and can exceed 60 C, therefore accessibility
should be prevented during operation.
3. Explanation of Symbols
This symbol means Caution, risk of
danger and the installation manual
should be consulted before
proceeding.
This symbol means Caution, risk of electric shock.
This symbol indicates the Functional Earth (ground) terminal.
This symbol means Caution, hot surface
!

Issue 2 Page 6 of 16
4. Applicable standards
The unit is CE marked and the standard units are UL listed.
The Standards applied are:
BS EN61010-1: 2001 and UL61010A-1
Safety requirements for electrical equipment for measurement, control and
laboratory use.

Issue 2 Page 7 of 16
5. Installation
The connector details on the standard unit and VCC versions are shown in table 1
overleaf. The DCC version is shown in table 2. See section 5 for more information on various
connection methodologies.
Table 1 : Non /DCC units connector pin-out
Pin
Signal Name
Parameters
1
Power Ground
Power Ground
2
+24Vdc Input
+24Vdc @ 2 amp maximum
3
Voltage Monitor Output
0 to 10 Vdc equals 0 to 100% of rated output, Zout =
2.2kΩ
4
Local Programming
Potentiometer Wiper Output
Potentiometer connected to +10Vdc reference and
ground, 0 to 10Vdc adjustable wiper output provided
5
Voltage Program Input
0 to 10 Vdc equals 0 to 100% of rated output, Zin =
10MΩ
6
Voltage Program Differential
Amplifier Output
0 to 10 Vdc equals 0 to 100% of rated output, Zout =
2.2kΩ
7
Voltage Program Differential
Amplifier Input – Positive
0 to 10 Vdc differential between pin 7 and pin 9 equals
0 to 100% of rated output, diode clamped to ground,
Zin = 38kΩ
8
Current Monitor Output
0 to 10 Vdc equals 0 to 100% of rated output, Zout =
2.2kΩ
9
Voltage Program Differential
Amplifier Input - Negative
0 to 10 Vdc differential between pin 7 and pin 9 equals
0 to 100% of rated output, diode clamped to ground,
Zin = 38kΩ
10
Internal Connection
Do Not Use
11
Current Program Input
Standard: Internally connected to provide 110% fixed
current limit
VCC Option: 0 to 10 Vdc equals 0 to 100% of rated
output, Zin = 1MΩ
12
Enable Input
Low = Enable. TTL, CMOS, open collector compliant
13
Internal Connection
Do Not Use
14
Internal Connection
Do Not Use
15
Signal ground
Ground for program and monitor signals

Issue 2 Page 8 of 16
Table 2 : /DCC units connector pin-out
The unit is contained in an earthed case, which should be securely mounted and the HV
output cable must be terminated safely.
Pin
Signal Name
Parameters
1
Power/Signal Ground
Ground
2
+24Vdc Input
+24Vdc @ 2A maximum
3
Voltage Monitor Output
Not used
4
Local Programming
Potentiometer Wiper Output
Potentiometer connected to +10Vdc reference and
ground, 0 to 10Vdc adjustable wiper output provided
5
Internal Connection
Do not connect
6
Voltage Program Differential
Amplifier Output
Not used
7
Voltage Program Differential
Amplifier Input – Positive
Not used
8
Current monitor output
Not used
9
Voltage Program Differential
Amplifier Input - Negative
Not used
10
Internal Connection
Do not connect
11
Current Program Input
Not used
12
Enable Input
Low = Enable. TTL, CMOS, open collector compliant
13
Internal Connection
Do not connect
14
TxD
Transmit data (output) wrt pin 1
15
RxD
Receive data (input) wrt pin 1

Issue 2 Page 9 of 16
Mechanical Outline 1kV to 10kV units.
150.0
95.0
Fixing face
15w D-plug
Customer Adjust Point
70716
TOP OF UNIT
33.5
SIDE OF UNIT
CALIBRATION
VOID IF SEAL
BROKEN
69.0
MOUNTING HOLE TEMPLATE
VIEWED FROM TOP OF UNIT
(NOTE - Max thread depth into unit is 5mm)
Unit Footprint
HOLE Ø3.5mm
IN 3 POSITIONS
8.0
48.0
46.012.0

Issue 2 Page 10 of 16
Mechanical Outline 15kV to 20kV units.
185.0
95.0
Fixing face
15w D-plug
Customer Adjust Point
70972 iss A
TOP OF UNIT
33.5
SIDE OF UNIT
CALIBRATION
VOID IF SEAL
BROKEN
64.0
MOUNTING HOLE TEMPLATE
VIEWED FROM TOP OF UNIT
(NOTE - Max thread depth into unit is 7mm)
Unit Footprint
HOLE Ø4.5mm
IN 3 POSITIONS
12.0
44.0
46.012.0
Fixings
M3 x 0.5 blind inserts, maximum thread depth 5mm. (1kV – 10kV)
M4 x 0.7 blind inserts, maximum thread depth 6.5mm. (15kV – 20kV)

Issue 2 Page 11 of 16
6. Connection Details
6.1. Remote DAC control
The differential input allows the voltage programming circuit to be remote from the
power supply. It prevents voltage drops in the ground connection from affecting the
programming signal. However, if there are voltage drops in the ground connection, the
DAC should be provided with its own reference.
24V Power input on Pin 2.
Ground on Pin 1.
0 to 10V voltage control signal to Pin 7.
Signal ground reference for 0 to 10V control signal. (Must be connected to signal
ground for 0 to 10V voltage control)
Link Pin 5 to Pin 6.
Connect Enable Pin 12 to ground to enable HV output.
Voltage monitor output is on Pin 3.
Current monitor output is on pin 8.
Signal ground on pin 15.
INTERNAL
TRIM
POWER COMMON
70456 issA
DAC
(1)
REF
OUT
(4)
(9)
(7)
(2)
+24V
(12)
ENABLE
0V SUPPLY
MPS
VMON (3)
IMON (8)
HV OUT
POT
10V REF
HV
+
-
(6)
(5)
POWER COMMON
REF
REMOTE DAC CONTROL
(15)
SIGNAL GROUND

Issue 2 Page 12 of 16
6.2 Local DAC control
The unit has an internal potentiometer near the D type input connector, which is
conected to the +10V reference. The output from the wiper of the internal pot may be
used as a reference for the DAC. Set the internal pot to maximum to make the +10V
reference available to external circuits.
It is not necessary to use the differential input when the voltage control circuit is close
to the power supply, however it is important to connect all grounds at Pin 1 of the PSU
to prevent voltage drops in the ground circuit from affecting the programming signal.
Take care to avoid ground loops.
24V Power input on Pin 2.
Ground on Pin 1.
DAC output to Pin 5.
Connect Pin 4 to the DAC reference input.
Set the internal pot to maximum.
Connect Enable Pin 12 to ground to enable HV output.
Voltage monitor output is on Pin 3.
Current monitor output is on pin 8.
The signal ground on pin 15 should be used as the ground for the VMON and IMON
signals and the reference ground for the DAC to achieve the best performance.
LOCAL DAC CONTROL
(5)
(6)
-
+
HV
10V REF
POT
HV OUT
IMON (8)
VMON (3)
MPS
0V SUPPLY
ENABLE
(12)
+24V
(2)
(7)
(9)
(4)
OUT
REF
(1)
DAC
70456 issA
POWER COMMON
TRIM
INTERNAL
(15)
SIGNAL GROUND

Issue 2 Page 13 of 16
6.3 Internal potentiometer control
The unit has an internal potentiometer near the D type input connector, which is
connected to the +10V reference. The unit may be controlled by the internal
potentiometer as follows: -
24V Power input on Pin 2.
Ground on Pin 1.
Link Pin 4 to Pin 5.
Connect Enable Pin 12 to ground to enable HV output.
Voltage monitor output is on Pin 3.
Current monitor output is on Pin 8.
Note : The signal ground available on pin 15 should be used as the ground for the
VMON and IMON signals to achieve the best performance.
POWER COMMON
(1)
ENABLE
(12)
MPS
IMON (8)
(2)
(4) INTERNAL
POT
(9)
(7)
10V REF
TRIM
-
+
HV
+24V (6) (5)
HV OUT
VMON (3)
INTERNAL POT CONTROLLED
0V SUPPLY
(15)
SIGNAL GROUND

Issue 2 Page 14 of 16
6.4 External potentiometer control
The unit has an internal potentiometer near the D type input connector, which is
connected to the +10V reference. An external potentiometer may be connected to the
wiper of the internal pot. Set the internal pot to give the desired maximum output
voltage and control the unit using the external potentiometer.
The unit may be controlled by an external potentiometer as follows: -
24V Power input on Pin 2.
Ground on Pin 1.
Link Pin 4 to external pot CW.
Link Pin 1 to external pot CCW.
Link Pin 5 to external pot wiper.
Connect Enable Pin 12 to ground to enable HV output.
Voltage monitor output is on Pin 3.
Current monitor output is on Pin 8.
Note : The signal ground on pin 15 should be used as the ground for the VMON and
IMON signals and the ground for the external potentiometer to achieve the best
performance.
INTERNAL
POT
10V REF
EXTERNAL POT CONTROLLED
POWER COMMON
(1)
(2)
POT
EXTERNAL
(4)
(9)
(7) TRIM
+24V
0V SUPPLY
ENABLE
(12)
MPS
HV
-
+
(5)
(6)
IMON (8)
HV OUT
VMON (3)
(15)
SIGNAL GROUND

Issue 2 Page 15 of 16
6.5 RS232 control (/DCC) versions only
The unit has RS232 (or RS485) communication facilities available via pins 14 and 15
of the 15 way ‘D’ connector. For the protocol used refer to unit specification, the
‘standard’ protocol can be provided on request.
The unit may be controlled digitally as follows: -
24V Power input on Pin 2.
Ground on Pin 1.
RS232 transmit on pin 14 – connect to Rx pin on PC
RS232 receive on pin 15 – connect to Tx pin on PC
Connect Enable Pin 12 to ground to enable HV output. This is independent of the
firmware/communications interface and can be used to shutdown the HV output.
If required there are analog monitor outputs available :-
Voltage monitor output is on Pin 3.
Current monitor output is on Pin 8.
However these are intended mainly for indication only, the primary control and
monitoring function should be performed via the digital interface.
INTERNAL
POT
10V REF
RS232 Control
POWER
COMMON
(1)
(2)
(4)
(9)
(7)
TRI
M
+24V
0V SUPPLY
ENABLE
(12)
MPS
HV
-
+
(5)
(6)
IMON
(8)
HV OUT
VMON
(3)
RS232 signal ground
uC
(14)
RS232 Transmit
RS232 Receive
(15)

Issue 2 Page 16 of 16
Note: Failure to comply with the above could compromise the safe operation of the unit and
invalidate the warranty.