iseg NHQ STANDARD Series User manual

Spezialelektronik GmbH
iseg Spezialelektronik GmbH Email: [email protected] Phone ++ 49 351 / 26 996 - 0
Bautzner Landstr. 23 http://www.iseg-hv.com Fax ++ 49 351 / 26 996 - 21
D - 01454 Radeberg / Rossendorf Germany
NHQ x08L
NHQ x010
Precision NIM High Voltage Supply NHQ STANDARD series
RS232 Interface
Operator Manual
Contents:
1. General information
2. Technical Data
3. NHQ Description
4. Front panel
5. Handling
6. RS232 Interface
7. Program example
8. CE Certificate
Appendix A: Block diagram
Appendix B: Rotary switch locations
Attention!
-It is not allowed to use the unit if the covers have been removed.
-We decline all responsibility for damages and injuries caused by an improper use of the
module. It is highly recommended to read the operators manual before any kind of
operation.
Note
The information in this manual is subject to change without notice. We take no responsibility whatsoever for any
error in the document. We reserve the right to make changes in the product design without reservation and
without notification to the users.
Filename NHQx08_010_01_eng.___; version 2.04 as of 98-06-04

Spezialelektronik GmbH
iseg Spezialelektronik GmbH Email: [email protected] Phone ++ 49 351 / 26 996 - 0
Bautzner Landstr. 23 http://www.iseg-hv.com Fax ++ 49 351 / 26 996 - 21
2 D - 01454 Radeberg / Rossendorf Germany
1. General information
The NHQ x0xx is a one or two channel NIM High Voltage PS. The unit is 1 slot wide and offers either manual
control and remote control via RS232 Interface. Remote control is also optionally available via the CAN-Bus
interface according to the CAN specification 2.0 A. The use of remote control supports extended functionality
compared to manual control.
The high voltage supply provides high precision output voltage together with very low ripple and noise even
under full load. Separate 10%-steps hardware switches set voltage and current limits. An INHIBIT input protects
sensitive devices which are connected to the output. The maximal output current per channel is also
programmable via the interface. The high voltage output is protected against overload and short circuit. The HV-
GND is connected to the chassis and the powering GND.
2. Technical Data
NHQ 208L
2 x 8 kV / 1 mA
NHQ - one channel
- two channel 108L 208L 1010 2010
Output voltage Vout 0 to 8 kV 0 to 10 kV
Polarity of output voltage switchable factory fixed
Output current Iout 0 to 1 mA 0 to 0,5 mA
Ripple and noise f ≥1 kHz: max. 50 mVP-P
f < 1 kHz: max. 200 mVP-P
LCD Display 4 digits with sign, switch controlled
-voltage display in [V], -current display in [µA]
Resolution of voltage 1 V
measurement current
1 µA, with option 104: 100 nA at Iout max ≤100 µA
Accuracy voltage ± (0,05% Vout + 0,02% Vout max + 1 digit) for one year
current ± (0,2% Iout + 0,02% Iout max + 1 digit) for one year
Stability ∆Vout / VINPUT < 5 ∗10-5
∆Vout < 5 ∗10-5 (idle to max. load)
Temperature coefficient < 5 ∗10-5/K
Voltage control CONTROL switch in:
upper position - manual: 10-turn potentiometer,
lower position - DAC: control via interface
Rate of change of - HV -ON/OFF (hardware ramp): 500 V/s
Output voltage - control via interface (software ramp):2 - 255 V/s
Protection - separate current and voltage limit
(hardware, rotary switch in 10%-steps),
- INHIBIT (external signal, TTL-level, Low active),
- programmable current limit (software)
Power requirements VINPUT ± 24 V (< 800 mA, one channel < 400 mA),
± 6 V (< 100 mA), with option N24: only ± 24 V
Temperature range Operating: 0 . . . 50 °C Storage: -20 . . . +60 °C
Packing NIM Standard chassis: NIM 1/12
Connector (on the rear) NIM: 5-pin; Interface: 9-pin female D-Sub
8 kV 8 kV SHV Radiall male connector,
opt. Lemo straight socket PSA 1Y 410 CLL C57 (see 10kV)
HV connector
(on the rear) 10 kV Lemo straight socket PSA 1Y 410 CLL C57
(Couppler: Lemo straight plug FFA 1Y 410 CLA C57)
INHIBIT connector 1-pin Lemo-hub

Spezialelektronik GmbH
iseg Spezialelektronik GmbH Email: [e-mail] Phone ++ 49 351 / 26 996 - 0
Bautzner Landstr. 23 http://www.iseg-hv.com Fax ++ 49 351 / 26 996 - 21
D - 01454 Radeberg / Rossendorf Germany 3
3. NHQ Description
The function is described in a block diagram of the NHQ xxx , see Appendix A.
High voltage supply
A patented high efficiency resonance converter circuit, which provides a low harmonic sine voltage on the HV-
transformer, is used to generate the high voltage. The high voltage is rectified by using a high speed HV-
rectifier, and the polarity is selected via a high-voltage switch. A consecutive active HV-filter damps the
remaining distortion and ensures low ripple and noise values as well as the stability of the output voltage. A
precision voltage divider is integrated into the HV-filter to provide the set value of the output voltage, an
additional voltage divider provides the measuring signal for the maximum voltage control. A precision
‘Measuring and AGC amplifier’ compares the actual output voltage with the set value given by the DAC
(computer control) or the ten turn pot (manual control). Signals for the control of the resonance converter and
the stabiliser circuit are derived from the result of the comparison. The two-stage layout of the control circuit
results in an output voltage, stabilised to very high precision to the set point.
Separate security circuits prevent that the front-panel switch settings for the current Imax and voltage Vmax limits
could be exceeded. A monitoring circuit prevents malfunction caused by low supply voltage.
The internal error-detection-logic evaluates the corresponding error signals and the external INHIBIT signal. It
also allows the detection of short-over-current due to single flashover.
Digital control unit
A micro controller handles the internal control, evaluation and calibration functions for both channels. The actual
voltages and currents are read cyclically by an ADC, connected by a multiplexer and processed to be displayed
on the 4 digit LCD. The current and voltage hardware limits are retrieved cyclically several times per second.
The reference voltage source provides a precise voltage reference for the ADC and generates the control
signals in the manual operation mode.
In remote control the set values for the corresponding channels are generated by a 16-Bit DAC.
Filter
A special quality of the unit is a tuned filtering concept, which prevents the unit against electromagnetic
interference and also the irradiation of the module to the outside world. A filtering network is located close to the
connectors of the supply voltage and the converter circuits of the individual devices are also protected by filters.
The high-voltage filters are housed in individual metal enclosures to shield even against minimum irradiation.

Spezialelektronik GmbH
iseg Spezialelektronik GmbH Email: [email protected] Phone ++ 49 351 / 26 996 - 0
Bautzner Landstr. 23 http://www.iseg-hv.com Fax ++ 49 351 / 26 996 - 21
4 D - 01454 Radeberg / Rossendorf Germany
4. Front panel
[1] 4 digit LCD display
[2] Channel switch
[3] Measuring switch
[4] Rotary switch Voltage limit
[5] Rotary switch Current limit
[6] Error indicator
[7] 10 - turn potentiometer
[8] HV-On indicator
[9] HV-On switch
[10] Control switch
[11] Polarity indicator
[12] KILL switch
[13] INHIBIT input
5. Handling
The NIM connector, the Sub-D-9 connector for the interface and the LEMO High voltage output connector is on
the rear side of the unit.
The output polarity for the 8 kV unit is selected with help of the rotary switch on the cover side (see appendix B).
The output polarity for the 10 kV unit is factory fixed according to customer concern.
The chosen polarity is displayed on the LED [11] on the front panel and also as a sign on the LCD display [1].
Attention! It is not allowed to change the polarity under power!
An undefined switch setting (not at one of the end positions) will cause no output voltage.
The High Voltage output is switched to on with HV-ON switch [9] at the front panel. The yellow LED [8] is
flashing if the units works well.
Attention!
If the CONTROL switch [10] is in upper position (manual control), the high voltage is
generated at the HV-output connector on the rear side with a ramp speed of 500 V/s
(hardware ramp) to the set voltage chosen via the 10-turn potentiometer [7].
This is also the same, if the unit is switched from interface control to manual control.
If the CONTROL switch [10] is in lower position (DAC) the high voltage will be activated only after receiving
corresponding interface commands.
Attention! If the ‘Autostart’ mode has been activated during the most recent operation then the
output voltage will be generated following the herewith stored parameters.

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iseg Spezialelektronik GmbH Email: [e-mail] Phone ++ 49 351 / 26 996 - 0
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Output voltage in [V] or output current in [µA] will be displayed on the LCD [1] depending on the position of the
Measuring switch [3].
Channel switch [2] is to select which channel will be displayed, channel (A) or channel (B).
During manual control (CONTROL switch [10] to potentiometer), the output voltage can be set via the 10-turn
potentiometer [7] in a range of 0 to the maximum voltage.
If CONTROL switch [10] is switched to DAC, the DAC takes over the previous output voltage setting of the
manual control. Via the interface the output voltage can be generated under a programmable ramp speed
(software ramp) of 2 to 255 V/s in a voltage range of 0 to the maximum voltage.
A programmable current trip for the maximum allowed output current per channel can be set with the maximum
possible resolution of the current measurement. If the output current exceeds the programmed limit, the output
voltage will be shut off permanently by the software. Restart the voltage is possible after ”Read status word”
and then ”Start voltage change”via serial interface. If ”Auto start”is active, ”Start voltage change”is not
necessary.
The maximum output voltage and current can be selected in 10%-steps with the rotary switches Vmax [4] and Imax
[5] ( switch dialled to 10 corresponds to 100%) independently of programmable current trip. The case where the
output voltage or output current will exceed the limits will be displayed by the red error LED on the front panel
[6].
Function of the KILL switch [12]:
Switch to the right position:
(ENABLE KILL) The output voltage will be shut off permanently without ramp on exceeding Imax or
in the presence of an INHIBIT signal (Low=active) on the INHIBIT input [13]. The
restart of the output voltage is possible after using the switches HV-ON [9] or
KILL [12] or during remote control ”Read status word”and then ”Start voltage
change”. If ”Auto start”is active, ”Start voltage change”is not necessary.
Note: If any capacitance is connected to the HV-output or if the rate of change of the
output voltage is high (hardware ramp) at high load, then the KILL function will be
released due to the current which is charging this capacitor. In this case a slower
rate of output change (software ramp) is recommended or ENABLE KILL should
not be selected before the output voltage has arrived the set voltage.
Switch to the left position:
(DISABLE KILL) The output voltage will be limited to Vmax, and the output current to Imax .; INHIBIT
shuts the output voltage off without ramp. The previous voltage setting will be
reset together with hard or software ramp if INHIBIT is no longer present.
6. RS232 interface
The most important parameters of the high voltage supply can be set and read under computer control via the
RS232 interface.
RS232 control mode
1st Write function: set voltage; ramp speed; maximal output current (current trip); auto start
2nd Switch function: output voltage = set voltage, output voltage = 0
3rd Read function: set voltage; actual output voltage; ramp speed; actual output current;
current trip; auto start ; hardware limits current and voltage; status
Front panel switches i.e. manual control is on higher priority compared to software control.
Manual control mode
During manual control , RS232 read cycles are interpreted only. Commands are accepted, but do not result into
a change of the output voltage.

Spezialelektronik GmbH
iseg Spezialelektronik GmbH Email: [email protected] Phone ++ 49 351 / 26 996 - 0
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Specification RS232 interface
The data exchange is character based, synchronisation between the computer and the supply (input) is
performed using echo. The data transfer to the computer (output) is asynchronous, breaks between two
characters, programmable of the break time, allow the computer to receive and evaluate the incoming data.
Break time is setting 3 ms at works.
The hardware setting of the RS232 interface is 9600 bit/s, 8 bit/character, no parity, 1 stop bit.
Signal transmission is performed potential free via the RxD and TxD, relative to GND.
The HV-supply is equipped with a 9 pin female D-Sub connector, the connection can be set up using a 1:1
extension cord (no null modem cable) when a PC is used. The pin assignment is given in table 1. Control
signals to be bridged on the PC side when a three lead cable is used, are given in table 1 also.
Syntax
The commands are transmitted in ASCII. The end of command is formed by the sequence <CR> <LF>
( 0x0D 0x0A , 13 10 respectively). Leading zeroes can be omitted on input, output is in fixed format.
In order to assure synchronisation between the computer and the supply at first <CR><LF> has to be sent.
Command set
command Computer HV-supply
Read module identifier # * # * nnnnnn ; n.nn ; U ; I *
(unit number ; softwarerel. ; Vout max ; Iout max )
Read break time W * W * nnn * (break time 0 ... 255 ms)
Write break time W=nnn * W=nnn * * (break time = 0 - 255 ms)
Read actual voltage channel 1 U1 * U1 * {polarity / voltage} * (in V)
Read actual current channel 1 I1 * I1 * {mantisse / exp. with sign} * (in A)
Read voltage limit channel 1 M1 * M1 * nnn * (in % of Vout max)
Read current limit channel 1 N1 * N1 * nnn * (in % of Iout max)
Read set voltage channel 1 D1 * D1 * {voltage} * (0 to 9999) (in V)
Write set voltage channel 1 D1=nnnn * D1=nnnn * * (0 < voltage in V ≤9999; <M1)
Read ramp speed channel 1 V1 * V1 * nnn * (2 ... 255 V/s)
Write ramp speed channel 1 V1=nnn * V1=nnn * * (ramp speed = 2 - 255 V/s)
Start voltage change channel 1 G1 * G1 * S1=xxx * (S1 , ⇒Status information)
Write current trip cannel 1 L1=nnnn * L1=nnnn * * (corresponding current resolution > 0)
Read current trip channel 1 L1 * L1 * nnnn * (s.a., for nnnn=0 ⇒no current trip)
Read status word channel 1 S1 * S1 * xxx * (S1 , ⇒Status information)
Read module status channel 1 T1 * T1 * nnn * (code 0...255, ⇒Module status)
Write auto start channel 1 A1=nn * A1=nn * * (conditions ⇒Auto start)
Read auto start channel 1 A1 * A1 * n * (8 ⇒auto start is active; 0 ⇒inactive)
* = <CR><LF>
The second channel of the supply is addressed by replacing 1 with 2 !
Table 1: Signal HV-supply PC PC Connection
RS 232 DSUB9 Int. DSUB9 DSUB25 3-lead cable
Signal pin assignment RxD 2 2 3
TxD 3 3 2
GND 5 5 7
4
─┐ 4 20 ─┐
6
─┤ 6 6 ─┤
8
─┘ 8 5 ─┘

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Status information:
xxx: ON<SP> Output voltage according to set voltage
OFF Channel front panel switch off
MAN Channel is on, set to manual mode
ERR Vmax or Imax is / was exceeded
INH Inhibit signal was / is active
QUA Quality of output voltage not given at present
L2H Output voltage increasing
H2L Output voltage falling
LAS Look at Status (only after G-command)
TRP Current trip was active
If output voltage shut off permanently (by ERR or INH at ENABLE KILL or TRP) you must do ”Read status
word”before the output voltage restoring is possible.
Error codes:
???? Syntax error
?WCN Wrong channel number
?TOT Timeout error (with following reinitialization)
?<SP>UMAX=nnnn Set voltage exceeds voltage limit
Module status:
Status Description Bit Valency
QUA Quality of output voltage not given at present 7=1 128
ERR Vmax or Imax is / was exceeded 6=1 64
INH INHIBIT signal was / is active 5=1 32
inactive 0
KILL_ENA KILL-ENABLE is on 4=1 16
off 0
OFF Front panel HV-ON switch in OFF position 3=1 8
ON position 0
POL Polarity set to positive 2=1 4
negative 0
MAN Control manual 1=1 2
via RS 232 interface 0
T1: U/I Display dialled to voltage measurement 0=1 1
current measurement 0
T2: A/B Channel dialled to channel A 0=1 1
channel B 0

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Auto start:
Description Bit Valency
If module status OFF + ERR + INH + MAN = 0, output voltage of the channel ramping
at set voltage. G-command is not necessary after D-command, POWER-ON and
OFF ⇒ON.
If output voltage shut off permanently (by ERR or INH at ENABLE KILL or TRP), the
previous voltage setting will be restored with software ramp after ”Read status word”.
3=1 8
Values loading in corresponding Current trip saving in EEPROM 2=1 4
registers at POWER-ON! Set voltage saving in EEPROM 1=1 2
Ramp speed saving in EEPROM 0=1 1
(EEPROM guarantee 1 million saving cycles)
Software
Contact us for an overview on our user friendly control and data acquisition software!

Spezialelektronik GmbH
iseg Spezialelektronik GmbH Email: [e-mail] Phone ++ 49 351 / 26 996 - 0
Bautzner Landstr. 23 http://www.iseg-hv.com Fax ++ 49 351 / 26 996 - 21
D - 01454 Radeberg / Rossendorf Germany 9
7. Program example
/***************************************************************************************************/
/* */
/* nhq.cpp */
/* */
/* example program for iseg nhq hv boards, written by Jens Römer, 27.2.97 */
/* */
/* this code was compiled under BC, please contact iseg for the source file */
/* */
/***************************************************************************************************/
#include <dos.h>
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include "int14.h" // COM2 handling
const etx= 0x03;
const f = 0x0a;
const cr = 0x0d;
unsigned char readU[]={'U','1',cr,lf,etx}; //read voltage
unsigned char sendU[]={'D','1','=','1','0',cr,lf,etx}; //set voltage to 10V
unsigned char *ptr;
unsigned char rby;
int i, cnt;
boolean ok;
void main(void)
{
clrscr();
COM2_init();
COM2_set(9600); // COM2: 9600 baud, 8 databits, no parity, 1 stopbit
ok=True_;
ptr=readU;
for (;;)
{
if (*ptr==etx) break;
COM2_send(*ptr); //send one byte
rby=COM2_read(); //read one byte
if (rby!=*(ptr++)) ok=False_; //compare sent with read data
else switch (rby)
{
case lf : printf("%c",lf); break;
case cr : printf("%c",cr); break;
default : printf("%c",rby); break;
}
if (ok==False_)
{
printf("No coincident read data found!");
exit(1);
}
}
cnt=8;
do
{
rby=COM2_read(); //read voltage data
switch (rby)
{
case lf : printf("%c",lf); break;
case cr : printf("%c",cr); break;
default : printf("%c",rby); break;
}
cnt--;
} while (cnt>=1);
}

Spezialelektronik GmbH
iseg Spezialelektronik GmbH Email: [email protected] Phone ++ 49 351 / 26 996 - 0
Bautzner Landstr. 23 http://www.iseg-hv.com Fax ++ 49 351 / 26 996 - 21
10 D - 01454 Radeberg / Rossendorf Germany
8. CE Certificate
CE - Certificate
This is to certify that the manufacturer
iseg Spezialelektronik GmbH
Bautzner Landstr. 23
D - 01454 Radeberg / Rossendorf
Germany
guaranties the compliance to the following:
VDE 0843 Part 3 / 02.88
VDE 0875 Part 11 / 07.92
VDE 0877 Part 1 / 03.89
EN 50082-2 / 02.96
ENV 50140 / 02.95
EN 61000 Part 4-2 / 03.96
EN 61000 Part 4-4 / 03.96
EN 61000 Part 4-6 / 04.97
EN 61000 Part 4-8 / 05.94
for the precision high voltage power supplies
of the NHQ STANDARD – Series.
Rossendorf, dated 30.09.98
Signed for Dr. Frank Gleisberg
Managing director

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iseg Spezialelektronik GmbH Email: [e-mail] Phone ++ 49 351 / 26 996 - 0
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D - 01454 Radeberg / Rossendorf Germany 11
Appendix A: Block diagram NHQ

Spezialelektronik GmbH
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POLARITY
NEG
POS
A
NEG
POS
B
Umschalten von neg. zu pos. /
switch from neg. to pos.
Umschalten von pos. zu neg. /
switch from pos. to neg.
POLARITY
NEG POS
A
NEG POS
B
NHQ mit Voutmax bis zu 5kV /
NHQ with Voutmax up to 5kV
Umschalten von pos. zu neg. /
switch from pos. to neg.
Umschalten von neg. zu pos. /
switch from neg. to pos.
NHQ mit Voutmax > 5kV /
NHQ with Voutmax > 5kV
Appendix B: NHQ side cover, Polarity rotary switch
e.g.: channel A, polarity negative
channel B, polarity positive