S p e z i a l e l e k t r o n i k G m b H
iseg Spezialelektronik GmbH
Email: [email protected]
Phone
++ 49 (0)351 / 26 996 – 0
Bautzner Landstr 23
http://www.iseg-hv.com
Fax
++ 49 (0)351 / 26 996 – 21
D - 01454 Radeberg / Rossendorf
Germany
7
Further environmental conditions
equipment is for use in closed environment only, maximum altitude of use 2000m,
relative humidity 20% to 90% (no condensation), maximum Polution degree level 2
Requirements for assembly, location
and mounting
Desk top power supply, backside fan must not be covered (distance of fan to any
object at least 3cm), unit should be placed close to an accessible power socket in
order to be able to pull the mains plug or operate the main switch in case of
emergency
Cleaning instructions
Use a soft, dry, lint-free cloth to clean the units exterior. Avoid getting moisture in
any openings. Do not spray any type of liquid directly on the device. Don‘t use
solvents, aerosol sprays or abrasives
The
built-in options
are marked on the rear side next to the type label
3 Functional
principle
The functional principle is described in the block diagram, Appendix A.
3.1
High voltage supply
For the high voltage generation a patented highly efficient resonance converter circuit is used, which provides a sinusoidal
voltage with low harmonics for the HV-transformer.
For the high voltage rectification high speed HV-diodes are used. A high-voltage switch, connected to the rectifier allows the
selection of the polarity.
The 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 a feedback voltage for the output
voltage control, an additional voltage divider supplies the signal for the maximum voltage monitoring.
A precision control amplifier compares the feedback voltage with the set value given by the DAC (remote 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 of 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 and changes the
output voltage according to the setup. This also allows the detection of short over currents due to single flashovers.
3.2
Digital control unit
A micro controller handles the internal control, evaluation and calibration functions of both channels.
The effective voltages and currents are read cyclically by an ADC with a connected multiplexer. The readings are processed
and displayed on the 4 digit LCD. The current and voltage hardware limits are retrieved cyclically several times per second.
A reference voltage source provides a precise voltage reference for the ADC and the control voltage for the manual
operation mode of the unit.
In the computer controlled mode the set values for the corresponding channels are generated by a 16-Bit DAC.
3.3 Filter
A special feature of the unit is a tuned filtering concept, which prevents perturbation of the unit by external electromagnetic
radiation, as well as the emittance of interferences by the module.
Summary of Contents for SHQ 122
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