Lexel 95 head Wiring schematic

[buffo]

Whoa!!! Dude - kill the motor.

I think Steve's point is that there are specific issues with this particular head / etalon controller / PSU combination. Issues that are not addressed with a simple schematic. That's why he's jumping on you.

Blowing up an otherwise perfectly good ion laser (and/or PSU) just because you forgot one small detail is one hell of a kick in the nuts. Since you are not versed in the specifics of these lasers (nor am I, or Marc for that matter), it makes sense to deferr to someone that does. Let it go, man...

Adam

[mixedgas]

WARNING IT IS NOT NORMAL PROCEDURE TO RUN a THREE PHASE LEXEL HEAD FROM SINGLE PHASE LEXEL POWER SUPPLY>

THIS IS DONE AT YOUR OWN RISK>

POSTER ASSUMES YOU KNOW TO TURN THE PSU OFF AND DISCONNECT IT FROM SHORE POWER BEFORE WORKING ON IT OR WHEN CHANGING TAP SETTINGS ON CATHODE.

POSTER ADMONISHES YOU TO CLOSELY WATCH THE CATHODE CONSUMED POWER WHEN RUNNING TO PREVENT TUBE DAMAGE.

POSTER REMINDS YOU YOU WILL HAVE LESS MAGNET AND LESS GAIN FROM THE TUBE.

Conversion to laser show laser from scientific laser

OK, if you pull the etalon card out of the socket, the etalon will be powered down. You then remove the brewster cover at the etalon end, unscrew the aluminum nipple on the etalon assembly that holds the brewster cover. Then remove the rear mirror. The etalon may now be gently pushed out using a Q-Tip. Catch the etalon on a folded piece of paper. The issue then becomes 3 pins on the 95 head connector. DO not touch the faces of the etalon with bare hands. They are very hard to clean. Leaving the etalon in while running multi-line will result in a 50% loss or greater of all lines power.

If your not going to use the etalon element, please put it on ebay for the holography types, who are always looking for one.

On the 95 head, the etalon power to the head is 120V will be wired from F (spare) a white wire, to N (line common) F(Spare) is normally not used on a 88. F(spare) on the 95 PSU will be wired to a 120V tap on LEG Y of the BUCK BOOST TRANSFORMER.

If you wish to power the etalon when hooked to a 88 supply, you need to find the high side of the cathode transfomer inside the 88 supply, this will be the 120V line from the buck boost (usually a small blue wire on the BB) and connect it to PIN F(spare) . The cold side of the 120VAC returns on the already existing line common wire (N) It is wise if taping the 120Vac to measure from it to pin N to confirm you have the right wire.

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Changing the 95 head over to a 88 PSU.

The 88 does not support the 28V emssion indicators of the 95 head. Disconnect PIN K (rad ind power) and leave it floating either in the head or at the connector in the umblical. Pin K is used on some OEM 88 supplies as a medical signal. Break the pin K circuit somehow.

95 head interlock circuit runs from PIN A(INTLK) to PIN C(INTLK) Leaving PIN C connected will cause problems on some medical 88 Supplies.

88 Head Interlock runs from PIN A (INTLK) to PIN D (INTLK)

Move the wire inside the 95 head connector from pin C to Pin D. leave PIN A alone.

MAKE SURE NO HEAD INTERLOCK WIRES, IE NEONS, GO TO ANNYTHING OTHER THEN A AND D
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WHen the 95 head is connected to the 88 supply, light mode will be out of calibration and may not function.
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NEXT UP, CATHODE SETTINGS.

THE 95 cathode is to be set at 3.4 volts ac 25 amps cold and no plasma IS 85 WATTS The 95 cathode hot is 3.2 volts 27 amps = 86 watts

The 88 cathode is however, a 2.6 V cathode. You must set the cathode transformer tap settings in such a to maintain 86 to 90 watts into the 95 cathode
or it will SAG. MOST 220V power lines in home environment will SAG DOWN when a 88 PSU is used to drive a 95 HEAD, and the first thing to reduce in power will be the CATHODE. COLD CATHODES SAG EASILY. YOU MUST MONITOR THE CATHODE WHILE RUNNING THIS WAY< OR YOU MAY GET A SAGGED CATHODE AND A DEAD HEAD. As you turn up the laser power, the cathode voltage will fall in most cases. This is very bad for the tube health.

__________________________________________________ ___________


88 POWER SUPPLY DO NOT EXCEED LIMITS>

A normal 88 tube is 167V +/- 3V at 25 A test. This is 165X25 = 4,000 watts.

the 95 TUBE which is 270V @ 30 AMps which is = 8100 watts.

therefore You can ask the 88 PSU for about 5000 watts max when using the 95 tube assuming correctly tapped and all transistors in the passbank are good. Above that and you start risking the system.

Keep the reg volts in the green. YOU MUST CORRECTLY SET THE CATHODE TRANSFORMER SWITCH FOR THIS TO WORK, AND KEEP THE TUBE POWER AT 4500 watts max while maintaining 85-90 watts CATHODE. THE MOST COMMON CAUSE OF CATHODE FAILURE IS BEING UNDERPOWERED.
Obviously most single phase lines will droop in voltage at 4500 watts or so. YOU HAVE TO WATCH THAT CATHODE POWER
REMEMBER YOUR MAGNET IS NOW HOGGING POWER THAT WOULD NORMALLY GO TO THE TUBE.

A copy of the 88 head schematic will be been placed in the FTP area under documentation. It is easier to make a 95 head a 88 then to make a 88 psu a 95 psu.

Filename is LEX88HD.ZIP

[Fotobysw]

Hi
Thanks all for the info so far. The reason I need 220v is that most of the smaller clubs here in Fresno have 220v and not 208 3phase. If what I have been told is right you almost have to have a trailer alone to haul a rotary converter. I now have bought a 95 supply that I think is or maybe can be converted to 220v with the 88 xformer but for the price I can't cry even if it takes some work.
Thanks
Steve Wall

[GooeyGus]

Hi
Thanks all for the info so far. The reason I need 220v is that most of the smaller clubs here in Fresno have 220v and not 208 3phase. If what I have been told is right you almost have to have a trailer alone to haul a rotary converter. I now have bought a 95 supply that I think is or maybe can be converted to 220v with the 88 xformer but for the price I can't cry even if it takes some work.
Thanks
Steve Wall

A rotary converter isn't TOO bad if that's the route you have to end up taking. Obviously 220v single phase would be desirable but my phase converter which uses a pretty darn big motor and some equally big starter capacitors is only about 150lbs with a ~2-3ft² footprint. Only downside is that one really has to keep on eye on the artificial leg to make sure the voltage doesn't drop at higher powers.

[mixedgas]

One thing I forgot to tell you. and I forgot because I was thinking a 88 psu, not a 95. The 95 is set up for a rectified 3 phase line, so the ripple is 360 hz and the filter cap is very small. The filter cap does need beefed up considerably for 120 hz. Like add a second cap, otherwise you get this wierd triangle wave in your tube current, followed by tube destruction when the cap blows.

One of my former employers insisted on running a 95 with a damaged cap to finish a important experiment. He thought I was crying wolf and another tech advised him it was no big thing. It cost him 7,000$ three days later. Large amounts of ripple kills tubes.

please keep that in mind. I would not have remembered it, and then Gus mentioned the cathode leg sag and it jumped into focus. Thanks Gus!
Steve

[QUAZAR]

Older ION lasers are NOT turnkey, you have to set them up correctly or the fireworks are spectacular and expensive

Steve

Oh yes. Been there, done that, cried.