LEXEL™ ion laser power supply is the most reliable yet developed,
providing a degree of convenience, flexibility and safety unmatched in the
The photos and captions below give an idea of the details and design that
go into making the power supply worry-free.
Thermal protective switches sense any abnormal temperature condition and
will de-energize the laser before any damage can take place.
Cooling water flow switch
A reliable flow switch is used to prevent operation without proper cooling
water flow. If the water is not on, the laser cannot be turned on. If the
cooling water is shut off while the laser is operating, there will be no
damage to the tube or other components.
A safety interlock deenergizes the power supply if the cover is removed.
Safety is an important part of LEXEL™'s design concept.
Clearly marked electrical test points are provided for measuring the most
important electrical parameters.
copper heat sink
The heat from the power transistors and associated components is
transferred into the cooling water by means of the solid copper heat sink.
The cooling water tubing is brazed directly to the copper plate so that
all of the heat is transferred without a thermal interface such as
sometimes exists in aluminum heat sink designs. A cool heat sink means
cool transistors; and cool transistors provide solid reliability.
Removal of the power supply
cover completely exposes the top and both sides for full access to the
components inside. Components are located so that they are easily
accessible for checking or maintenance.
Printed circuit cards provide the electronics for the Light and Current
The power supply is switched on and off by a large relay which applies and
disconnects the AC line power. This line contactor works in conjunction
with the pushbutton and interlock circuits to provide complete main power
control. This contactor may also be controlled from remote locations.
A multitapped auto-transformer is used to match the power supply to widely
different AC line voltages. Line voltages may be as low as 190 volts or as
high as 245 volts in different parts of the world. To force a transistor
regulator circuit to adjust for this range of line voltages directly is to
invite transistor failures. The LEXEL™ auto-transformer method allows an
optimum match to the AC line at installation. The regulator circuit will
thereafter reliably compensate for normal line voltage variations of 10%
Areas inside the power supply connected directly to the AC line and
therefore not interlocked, are covered with additional protective
These main fuses protect the diode rectifiers.
Copper water tubing
The cooling water in the power supply uses copper tubing. There are no
water hoses in LEXEL™ power supplies to blow off and flood the electronics.
The power transistors making up the current regulation circuit are mounted
to the copper heat sink using high thermal conductivity Be0 insulators.
Much of the high reliability of the LEXEL™ power supply comes from keeping
the transistors cool.
The electrical feedback signal from the light sampler in the laser head
connects to the Light Regulator and Power Meter electronics at this
Power to laser head
The interconnecting electrical cable from the laser head plugs into the
back of the power supply.
This output may be used to operate a power indicator such as LEXEL™'s Model
508 Remote Power Monitor.
The laser may be modulated by applying a signal to this connector. This
feature is often used to remotely change the laser power level or to pulse
from an idle level to a preset operating level.
Laser head water
The cooling water hoses to and from the laser head are connected to these
fittings. Like the electrical connection, the water hoses may be
completely disconnected from the power supply.
Water inlet and drain
The cooling water to and from the laser is connected to the power supply
using ordinary garden hose connections.
Provides terminals which must be electrically joined in order to energize
the laser. Complies with CDRH standards.
Each major component or subassembly is clearly marked with its identifying
symbol. This identification allows easy and direct comparison to the
schematics and parts list in the instruction manual.