5
1. Safety warning
This power supply produces a high DC volt-
age (up to 310V), which is potentially dangerous
for the user. It is therefore essential to under-
stand how it works and to follow a few simple
safety rules.
1.1. Operating principle
Any gas lamp - whether a simple neon lamp or a
sophisticated hollow-cathode spectral lamp - re-
quires a high DC voltage to excite the gas in the
lamp. The voltage required depends mainly on the
gas used; for example, neon requires around 60V,
whereas a Thorium-Argon (ThAr) lamp requires
over 200V.
The High Voltage power supply is therefore capable
of producing a high DC voltage (up to around
310V), to excite a wide variety of gases. Once the
gas excitation has started, a current regulator
takes over, adapting the voltage to maintain the
current.
The excitation holding voltage for a given current
is always lower than the excitation voltage itself.
On power-up, there is a voltage peak, then the
voltage drops significantly.
You can set the current using the potentiometer on
the front panel, and display it using the galvanom-
eter. The maximum current is 30mA.
In addition, power limiting reduces the risks, since
normal use of the power supply never requires
maximum voltage at the same time as maximum
current.
Ultimately, the stabilised operating voltage de-
pends mainly on the type of lamp you use.
Note that as the power supply incorporates current
regulation, it is naturally protected against short-
circuits.
1.2.Safety rules
To ensure your safety when using the high-voltage
power supply, it is essential to follow certain in-
structions.
•Any manipulation of the power supply (in-
stallation, connection of a lamp, etc.) must
be carried out with the power off, i.e. with
the switch in the OFF position and, if possi-
ble, with the 12V supply switched off.
•We strongly recommend that you set the
current potentiometer to the minimum po-
sition (0mA) when you first switch it on.
•Always use cables and plugs that are in
good condition, to avoid any risk of electro-
cution or short-circuiting.
•Never open the power supply unless you
are an experienced technician (you may be
held liable). The high-voltage power supply
contains sensitive components and may
present a high risk of electric shock, fire or
other hazards if handled incorrectly.
•Keep the power supply away from moisture
and heat sources, and avoid overloading
electrical sockets.
•In the event of malfunction or need for re-
pair, it is strongly recommended that you
contact the manufacturer (Shelyak Instru-
ments) for professional assistance.
For your information, an internal switch box will de-
connect it if the box is opened.
