M.G. HeNe Needing PSU.....

[RYDorDIE278]

Ok So I Got Given This Melles Griot Tube (05-LHP-073), it was used for "Confocal Laser Scanning Microscopy" In a Lab At The Largest Production Dairy factory in the world and it was replaced Because it was underperforming for its needs,

anyway... it states 5mW Maximum @ 632.8nm i have no idea of its value and it did not come with a free Power Supply, I was told after it was removed they put the terminals against a metal bench to Arc the power out of it before "disposal" so Im wondering if making it Arc could have damaged it or if this is normal practice for all You HeNe owners?

I Have read around the forums for general info and on google also before throwing a thread out here, Sams Laser FAQ was very helpful too,

So as far as Sams laser FAQ states im looking for a PSU that can supply 1.71KV @ 5mA , Now i am wondering if i can supply more than the rated voltage e.g 2.1KV as long as i only supply the rated 5mA, BTW Im Totally New to HeNe

I Have looked on ebay for PSU but without knowing more about PSU i would not purchase one yet

Any Feedback or Comments are Welcomed

 

[Sigurthr]

The tube acts like a large capacitor, retaining the high voltage used to power it for some time. It is harmless but painful, so they do tend to short it out when removing it. Totally safe.

You can exceed the voltage without worry, as long as it is close in rated current.

 

[Roam]

For your LHP, you can probably use Melles Griot LPM 824-065 power supply. I use that to run my 543.5 and 593.9 nm tubes, the latter has approximately the same resonator length as yours so must have similar rating. The only difference is that in your LHP all axial modes are linearly polarized hence the "P".

See the photos I attached.

 

[hakzaw1]

I think you just missed out on a Greedbay listing for two PSs one was working and about the same as y0u need the othger they think ids DOA- I dont need any or i would have looked harder as IIRC it was a good deal.
go to: SAM'S CLASSIFIEDS'- but NOT sure he ships out of the USA- but he warrantees all he sells-


Sam's email addy can be found there too- he may reply with some advice-
I keep 'HeNe' as a twice a day search and see many ..

" I was told after it was removed they put the terminals against a metal bench to Arc the power out of it before "disposal" so Im wondering if making it Arc could have damaged it or if this is normal practice for all You HeNe owners?"

AFAIK its SOP to short the alden plug -- I do it every time if i am going to take the laser from the PS-

with a screwdriver-

one brush against my arm was all I needed.

dont think i ever damaged one (laser)

just checked Greedbay and did not see any good deals on a power supply- Meridith always has some but he has fairly high prices(mi_laser)


you can post a WTB thread in the BS &T section-

guess you can look at this from two angles-

OK to pay for the PS -- the tube was free
OR- dont want to spend$$ on a tube i got free

I got almost all of mine on greedbay
it takes a lot of losing auctions to win one good one.

I never bid- but do much better sniping.

Sam has a section on building one ..

would be a shame to buy a PS only to find the tube was dead.

I have seen Alden plugs on neon sign lights - wondered if they could work on a laser--

:beer:

*************** back with new

I know this seller- N/Ps ever for me= gp tp Sam's and see if one of these will match your needs- the seller does ship to you- IMO the best part of this deal may be the PSUs as the tubes meter out to be well used (up)




http://www.ebay.com/itm/C109715-Lot...647?pt=LH_DefaultDomain_0&hash=item5b01c95ccf

Product ID # C109715
This lot includes three Helium Neon Laser Tubes [Melles Griot 05-LHP-073 (mfd. 10/01), Melles Griot 05-LHP-073-416 (mfd. 5/98), and Carl Zeiss Jena LGK 7634)], along with one Melles Griot 05-LPM-901-050 Power Supply, a Uniphase 314T-1700-4.9-4 Power Supply, and two laser tube mounts, as shown. These items look to be in good cosmetic condition, showing some signs of wear. The Melles Griot 05-LHP-073 Laser is missing its front end cover. All of the units power up, and the laser tubes emit a red laser beam. I tested the laser outputs with a laser power meter set to 633nm (not included): the Melles Griot 05-LHP-073 is putting out about 0.350mW, the Melles Griot 05-LHP-073-416 is putting out about 0.175mW, and the Zeiss Jena laser is putting out about 0.925mW. However, this is the extent of my testing of these items, and they are being sold as-is. Approximate overall unpacked dimensions: 13"L x 10"W x 6"H.

*************************************

they want 40$ to ship CONUS- no bids yet-- 17 hours left- IF I wanted these I would snipe at 6 seconds with a limit of $61.99

ship to NewZ would be $58.50 usd

 

[RYDorDIE278]

Thankz For the Info Sigurthr and Haksaw1, Like i Said im totaly new to HeNes and there much learning to be done,

For your LHP, you can probably use Melles Griot LPM 824-065 power supply. I use that to run my 543.5 and 593.9 nm tubes, the latter has approximately the same resonator length as yours so must have similar rating. The only difference is that in your LHP all axial modes are linearly polarized hence the "P".

See the photos I attached.

Ok Thanks for the Info also Roam! Ill sus me a power supply eventually, just dont want to rush for a good deal and get something thats a good deal but doesnt work with my HeNe or one that wrecks it,
may i ask where in NZ you are from Roam?

EDIT:Ohh cheerZ Haksaw1! fair bit of info there,
save me some work please! JKs
much appreciated,
i did see that bid a couple days ago but did not bother to read as i am mainly just after a PSU only, i think the shipping is just a little much for me, il probably sit back for a bit before i lunge to purchase one,
atleast now i have a fair idea what im looking for, like i know PSU can have more Kv as long as mA is spot on or close,

thankZ for the heads up too Haksaw1

 

[hakzaw1]

^^^ try to avoid double posting--edit then paste is the way unless its a FS thread and you need to keep it near the top...

not too late to fix BTW...
hak

 

[ultimatekaiser]

the power supplies generally have a range of voltages. try to aim for the middle of the compliance range for the supply. you can usually adjust the current with a trim pot on the side. a good supply for this tube is an 05-LPM-830-065. it runs 1.6-2KVDC @ 6.5mA (adjustable current though via a trim pot on the side)

extra voltage/current isn't too bad unless it's grossly overpowered, but if you run a power supply out of its range bad things can happen. and even if it doesn't damage the power supply or tube, it will shorten the tube's lifespan considerably from heat and the extra discharge. they should always be run as close to spec as possible. the output and stability, as well as the tube life will suffer otherwise.

 

[The Lightning Stalker]

 

[Sigurthr]

Looks good except there's no current or voltage regulation and if you don't size the resistor correctly the tube will go into oscillation when the trough of the Vipple dips too low. I mean I've done it before, it works, but so does running a tube on AC.

Handful of other parts and you can get rough regulations.

 

[Roam]

Hi RYDorDIE278! I'm from the North Shore in Auckland.

 

[The Lightning Stalker]

It isn't designed to be powered with a battery. As long as the input voltage is stable, it works well. The
idea was to use a few parts and keep it as simple as possible. None of the old HeNe power supplies had
current regulation. A 1k resistor can be inserted in series with the tube ground to check tube current
during initial setup, but isn't necessary once everything is set. Most of the ideas were taken directly from
the Laser FAQ.

 

[Sigurthr]

My point is that the flyback produces pulsed DC. If the RC low pass filter isn't sized accordingly you'll get ripple on the output regardless of how solid of DC power you feed it. You need a large enough R to keep C charged with the available current from the secondary, which is largely affected by the number of turns on the primary and the drive frequency. I wasn't bringing up regulation for overcurrent or overvoltage protection, but rather to ensure the tube is powered CW and not pulsed. As I said, it works, but it isn't very healthy for the tube if it goes into oscillation. A sense resistor, an opamp, and a VCO for drive would give you a regulated supply, or you could just use a logic gate to do pulse skipping if you oversize the RC filter (probably easier and cheaper).

 

[The Lightning Stalker]

That's why the R and C values are unmarked. They have to be tailored to each individual tube. If C is big
enough, it can work with almost any value of R within reason, but a really big C puts more stress on the
other components at startup.