Melles Griot 643 Ar-Kr... problems getting set up.

Greetings, everyone.

I have come into possession of an Omnichrome 'Series 43' 643-LICA-A01.

It turns out that someone at the university had chucked it out (!!) but it all appears physically intact, and included the laser head, power supply, and umbilical cable... so, even though it might not actually work, I figured it was well worth the gamble for me to pick it up anyway.

As far as I can tell, it's a re-badged Melles Griot 643 series, marketed for use in confocal microscopy, cell sorting, or some sort of biology stuff like that.

The safety label gives the wavelength(s) as 457-647 nm, which is consistent with a multi-line "white light" Ar-Kr laser.

I have the laser head, power supply, keyswitch keys and laser head cable. I don't have any manual or documentation, or the original cooling fans.

The laser appears identical to the one depicted in photos on this page, except that mine is a beige case with Omnichrome branding:

Argon-Krypton-Laser Melles Griot 643


Laser head

I have removed the ventilation duct connector thing from the top of the laser head casing and mounted my own fan on top, with an independent power supply. I don't have any original fan.

I've got nothing plugged into the 7-pin connector on the laser head, next to the main power umbilical connector. This is supposed to be for fan power supply, I think.

Inside the laser head, there is an interlock circuit which goes from pin 18 on the main umbilical connector, to the 7-pin fan connector, from the 7-pin connector through a couple of thermal circuit breakers, and back to pin 21 on the main power connector.

Pinout for the main umbilical cable is here - whilst the laser isn't exactly the same model, it appears to be consistent.

Sam's Laser FAQ - Complete Ar/Kr Ion Laser Power Supply Schematics

I have stuck a piece of wire into the connector (it's an odd connector, I don't have a mating connector) to connect the two interlock pins together, so now the circuit is complete. We can measure continuity between pins 18 and 21 on the umbilical cable, as measured from the power supply end.

There is no head cover interlock switch, and pins 2 and 5 are looped together on the main umbilical connector, inside the laser head.

There doesn't appear to be any kind of shutter interlock - there was a kineFlex fibre coupler mounted on the end of the laser when I got it, as well as a little gadget with a series of coloured gel filters on a rotating wheel controlled by a stepper motor - presumably to allow the wavelength you want to be electronically selected. I have removed those temporarily to get things going - now (with the laser off) I can look straight down the bore and see my eyeball reflected in what I presume is the output coupler mirror. So, there does not appear to be any output shutter installed.



Power supply

The power supply is badged as Omnichrome - but labelled on the back as a Melles-Griot 171B.

The power supply looks very similar to that depicted here - but not quite the same.

http://www.lamdapacific.com/mlx_manage/upload/200721316394734.pdf

The power supply has one of those big, high current (16 A max, IIRC) IEC power connectors, not the standard one you might find on, say, computers.

I made a mains power cable with a matching plug... it seems like perhaps it might be a slightly bad idea to plug this into a standard 10 A 240 VAC domestic socket... I'm not sure. I'll try it for a brief period of time and see if it trips the breaker.

(Oh, BTW... I'm in Australia... so it's a 240V 50 Hz AC mains device.)

There are four LEDs on the power supply - mains AC connected, beam interlock, safety interlock and standby.

There's a D25F connector for the remote control or whatever it is. I don't have any original cable or device designed to be plugged in here.

Following the information here, I have assembled a D25 plug with pins 1 and 3 and pins 19 and 21 jumpered together.

Sam's Laser FAQ - Complete Ar/Kr Ion Laser Power Supply Schematics



Operation

I have plugged in the laser head, turned on the fan, plugged in the D25 connector, and plugged in the mains power - with the power switch on the power supply switched off.

At this point, the green AC mains connected LED lights, as well as both of the two red interlock open LEDs.

Turn on the power switch. Nothing happens. LEDs remain the same.

Turn the keyswitch to ON. Nothing happens. LEDs remain the same.

Turn the keyswitch to START for a second, and release it to the ON position. Nothing happens. LEDs remain the same.

:cryyy:

Can anyone provide any ideas or suggestions?

Thanks

It seems to me that "interlock open" lights have it disabled. On my EnterpriseII, a burned out warning light will lock out the main power contactor.
This is quite advanced and perhaps someone on PL knows about this laser.

HMike

I took the keyswitch out of the power supply to fix it... and I forgot to plug it back in internally.

Now... it works

It emits a nice bright white with a touch of green-yellow without any filters, and the two gel filters that are installed provide green-yellow and a deep blue.

That sounds awesome! Very nice find, a few pics would be great of a white laser

^Agreed, i'd sure like to see this thing laseing :drool:

I need to get some camera batteries, but I'll try and do this in the not too distant future

Very nice find!!

Make sure you have enough air flowing through that tube... Really looking forward to seeing some pictures of this.

If you can get a PCAOM from somewhere you could make a really nice RGB!

I too would like to see pictures of goths whitelight - lucky bugger!

Here are some pics

Index of /luke/laser

I have left the pics at full resolution, so they might be a little bit bandwidth hungry.

Also, I haven't bothered to work through and delete all the crap ones...





No photoshop involved... just a small F-stop on the camera, and a bit of fog in the air.

Wow, that is one sweet laser, what does it draw from the wall?

Well you saved it from the dump, may it serve you for a long time. :beer: Have you had a chance to meter the laser, I wonder what it's putting out.


PS: Maybe you could make a thumbnail of the the image though, it is pretty damn big.

hehe yeah its four times wider than my 17" screen! Nice laser too - looks different inside with the "double" anode blocks

edit: oh and those beamz are bootiful! love the full colour spread in that shot! :jealous:

edit2: just read he found it in a dumpster. Now I am GREEN (532) with envy. You lucky so and so! $%^@##! lol

Awesome find.
You may want to look at a heavier duty fan. Not familiar with this model but Argons generate a lot of heat. Anyone with better info. please add to.

Hello Goth

Congratulation for this cool laser-unit!

The link you gave in your first post was my webpage

Argon-Krypton-Laser Melles Griot 643

I have the Melles Griot 643PERYB-A01, almost the same Laser as you and I'm very happy with the unit indeed. Because I had no power supply for this unit, I had to build one myself. This was fairly easy, because there had just some modifications to be done on the power supply for my American Laser Corporation ALC-60X Argon-Laser, so I can switch now between these two lasers. Some pictures of mine:

The Melles Griot 643 head in comparison with an American Laser Corporation ALC-60 head:



Power connectors of the head:



Frontside:



Whole unit:



The opened laser-head:








And some pics from the powered unit:

White beam splitted up with a grating:



Beam at 7A tube current, 6 blue lines, one yellow (seems like green on the photo) and a red one:





On the next running session I will take some more pictures.

More information about the laser unit and other projects (laser and high voltage / high frequency) can be found on my page:

Hochspannung als Hobby

Unfortunately everything is written in german, but maybe someday I will try to translate the whole page into English.

Greets argon ;-)

The white balance from those Melles units is stunning! Often you see Ar/Krs that are blue/green heavy, but these ones appear to be perfect. I wish I had one!!

you are one lucky mofo.
that is beautiful.

and for free. -__-'

Thank you for your reply, diachi and silvercookie. I have to admit, that in the picture the white seems a bit better than it is in reality In reality the beam is a bit greenish, but the line which appears green in the picture is yellow... my camera has some difficulties to "see" the actual colors as they really are...

Greets argon