| Question: |
Are the modules short circuit
proof? |
| Answer:
|
Yes. Every unit is shorted to
ground at least once during testing. But the high voltage should not
be discharged into the control or 24V power inputs. There may be problems
discharging a positive unit into a negative unit or a larger voltage
unit into a smaller voltage unit (e.g. 60 kV into a 30 kV output).
This will normally need extra protection circuitry. |
| |
| Question: |
Even continuous arcing? |
| Answer:
|
The power supplies are fitted
with short circuit protection resistors normally rated at a few watts.
If the arcing is very extreme and continues for a long time, these
resistors may over-dissipate and burn out. This can be avoided if
extra external protection is fitted (please consult us for more information). |
| |
| Question: |
Why must I connect the cable
shield (screen)? |
| Answer:
|
During arcing currents in excess
of 1000 Amps will flow. It is important that these currents return
to the high voltage power supply by the shortest possible route. The
modules are designed for this shortest route to be via the cable shield
(screen). In addition, all connections should be made using
substantial wires with good soldered or bolted connectors. Failure
to observe this will result in large voltage spikes appearing at the
control terminals during arcing and radiation of electromagnetic interference. |
| |
| Question: |
How do I connect up the modules? |
| Answer:
|
Each of the standard units have
a pin connections page (see: HP & KS,
HPR, HW, KW).
They can be connected so they operate from the internal potentiometer,
an external potentiometer or by external 0 to +10V control signal. |
| |
| Question: |
Will you modify them for me or
produce a special to my specification? |
| Answer: |
Yes, 60% of our production is
special units! Examples of some of these are shown on the products
page |
| |
| Question: |
How does the output change when
they are first turned on? |
| Answer: |
After the output is established,
at constant ambient temperature and other fixed conditions the output
will exhibit an exponential warm up curve. The amount of drift depends
on the unit temperature co-efficient (the lower the better e.g. HP
series 25 ppm/C). It also helps if the power supply is kept
as cool as possible and away from external heat sources. The
curve below is for a special unit with improved drift. |
