iseg EHQ 102M, EHQ 104M, EHQ 103M, EHQ 105M Operator's Manual

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

Precision High Voltage Sources in 3U Eurocard Format

Operators Manual

Contents:

1. General information

2. Technical Data

3. NHQ Description

4. Front panel

5. Handling

6. RS232 Interface

7. Program example

Appendix A: Block diagram

Appendix B: Rotary switch locations

Attention!

-The unit shall not be operated with the cover 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 EHQ10x_eng.___; Version 2.04 from 26.02.98

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 2

1. General information

The EHQ´s are one channel high voltage supplies in a 3U Eurocard Chassis, 8TE wide. The units offers manual
control and operation via RS232 interface (option: CAN Bus interface instead RS232). The use of the interface
supports more then the manual control functionality.
The high voltage supplies special provide high precision output voltage together with very low ripple and noise,
even under full load. Separate 10%-steps hardware switches put voltage and current limits. An INHIBIT input
protects connected sensitive devices. Additionally, the maximal output current is programmable via the interface.
The high voltage output protected against overload and short circuit. The output polarity can be switched over.

2. Technical data

Type (with RS 232) EHQ 102M EHQ 103M EHQ 104M EHQ 105M

Output voltage V

O

0 ... 2 kV 0 ... 3 kV 0 ... 4 kV 0 ... 5 kV

Output current I

O 24

0 ... 6 mA 0 ... 4 mA 0 ... 3 mA 0 ... 2 mA

Ripple and noise < 2 mV

P-P

< 5 mV

P-P

Resolution of current measurement

1 µA; Option 0n1: I

O max

= 100 µA ⇒ 100 nA
Resolution of voltage measurement 1 V
Accuracy current measurement ± (0,05% IO + 0,02% I

O max

+ 1 digit) for one year

voltage measurement ± (0,05% VO + 0,02% V

O max

+ 1 digit) for one year

LCD display 4 digits with sign, switch controlled

- voltage display in [V]

- current display in [µA]

Stability

∆ VO (no load / load) < 5 ∗ 10

-5

∆ VO/V

INPUT

< 5 ∗ 10

-5

Temperature coefficient

< 5 ∗ 10-5/K

Voltage control CONTROL switch in position

-manual: 10-turn potentiometer,

-DAC: control via serial interface
Rate of change of HV -ON/OFF 500 V/s (hardware ramp)
output voltage remote control 2 ... 255 V/s (software ramp)
Protection -separate current and voltage limit

(hardware, rotary switch in10%-steps)

-INHIBIT (external signal, TTL level, Low=active)

-programmable current limit (software)

Power requirement V

INPUT

± 24 V (< 500 mA), Option: ± 12 V ⇒ I

O 12

= I

O 24

/2
Operating temperature 0 . . . 50 °C
Storage temperature -20 . . . +60 °C
Packing 3U Euro cassette / 160 mm depth / 40,8 mm wide
Connector 96-pin connector according to DIN 41612
HV connector SHV-Connector at the front panel
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. EHQ Description

The function is described at a block diagram of the EHQ. This can be found in Appendix A.

High voltage supply

A patented high efficiency resonance converter circuit, which provides a low harmonic sine voltage on the HV­transformer, is used to generate the high voltage. The high voltage is rectified using a high speed HV-rectifier,
and the polarity is selected via a high-voltage switch. A consecutive active HV-filter damps the residual ripple 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 supplies 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 potentiometer (manual control).
Signals for the control of the resonance converter and the stabilizer circuit are derived from the result of the
comparison. The two-stage layout of the control circuit results in an output voltage, stabilized with very high
precision to the set point.
Separate security circuits prevent exceeding the front-panel switch settings for the current I

max

and voltage V

max

limits. 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
allows the detection of short overcurrent due to single flashovers in addition.

Digital control unit

A micro controller handles the internal control, evaluation and calibration functions of both channels. The actual
voltages and currents are read cyclically by an ADC with connected multiplexer and processed for display on the
4 digit LCD display. 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 generation of the control signals
in the manual operation mode of the unit.
The set values for the corresponding channels are generated by a 16-Bit DAC in computer controlled mode.

Filter

A special property of the unit is a tuned filtering concept, which prevents radiation of electromagnetic interference
into the unit, as well as the emittance of interference by the module. A filtering network is located next to the
connectors for 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 minimum interference radiation.

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 4

4. Front panel

[1] 4 digit LCD display
[2] Error indicator

[3] Measuring switch
[4] 10-turn potentiometer

[5] HV-ON switch

[6] CONTROL switch
[7] KILL switch

[8] INHIBIT input
[9] HV-ON indicator

[10] HV output
[11] Polarity indicator

5. Handling

The state of readiness of the unit is produced at the 96-pin connector according to DIN 41612 on the flipside.
The Output polarity is selectable with help of a rotary switch on the cover side (see appendix B). The chosen

polarity is displayed by a LED on the front panel [11] and 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.
High voltage output is switched on with HV-ON switch [5] at the front panel. The viability is signalled by the yellow

LED [9].

Attention! If the CONTROL switch [6] is in upper position (manual control), high voltage is generated

at HV-output [10] with a ramp speed from 500 V/s (hardware ramp) to the set voltage
chosen via 10-turn potentiometer [4].
This is also the case, if RS232 control is switched over to manual control while operating.

If the CONTROL switch [6] is in lower position (DAC), high voltage will be activated only after receiving
corresponding RS232 commands.

Attention!

If at the last working of the unit activated the function ″Autostart″, the high voltage will be
generated with the saved parameters immediately!