ALC 68 questions ?

[smogthemog]

Hi.

I had my ALC 68 fired up this afternoon and have a few questions I would like to ask about it. It's running on the original ALC PSU but I wondered what setting I need to be running it at to be safe to the tube. The three way switch just underneath the meter is a Watts power out / Tube Test / Tube current switch but it only seems to operate the meter when set to Tube current. It also has a rotary power output control on the front that has been wired somehow into the MIN potentiometer inside the PSU. If I have the switch set to Tube Current, the rotary power control set so it will fire up, the meter will read low end about 5A before it stops lasing and 22A with the power control cranked right around to full. It will only last about 30 seconds on full from cold before the overtemp cuts in. I have only done this twice for testing purposes, to get some readings.
So my question is, at what safe 'tube current' if it is tube current I am reading, do I want to be running it at?

I have yet to recondition this laser & PSU up to a better standard because it has come out of a working night club and is a little mucky. Anything I need to watch out for whilst doing this - apart from cap discharge ?

Thanks

Jim

PS - the blue ball was sat for ages in the airflow from the fan

[Laserman532]

Damn, now thats funny!!! ME TOO!!! I have always loved to float my balls over my fans!

[buffo]

According to the laser FAQ, that tube should be able to run at 20 amps continuously. Granted, that's the max rating for the tube, but it shouldn't shut down on overtemp at 20 amps. I think you might need to have TWO of those large squirrel-cage blowers mounted on that thing. The smaller fan on the front may not be moving enough air.

Having said that, I think I'd run that tube at between 12 and 15 amps to get some life out of it. It won't last nearly as long if you run it at 20 amps all day.

Adam

[p1t8ull]

I used to run one every weekend in the low 20's and it never overheated
once, but the centrifugal fan was quite a bit bigger than that one.
If you're cutting out at 20amps then either the mesh heatsinks are clogged, or your fans are not up to the job.
It's good to know the thermal trip is still wired and working though.

[smogthemog]

Thanks for the reply lads, that's given me a good insight into what to run it at.

It may well be the case that the fin's are partially blocked Simon, I haven't checked that yet. It's from out of a club and at the moment it';s filthy so I just hope it is that. The fan does seem to push a fair bit of air though but not having witnessed one of these before I don't know if it is enough.

Thanks

Jim

[smogthemog]

Damn, now thats funny!!! ME TOO!!! I have always loved to float my balls over my fans!

Are they Blue balls?

[Jem]

Damn, now thats funny!!! ME TOO!!! I have always loved to float my balls over my fans!

I MUST try that sometime

Jim, What's the laser output from the ALC68?, i'm just wondering if that's why i've got holes in the back of my Pangolin tee shirt ... Just kidding, it blows my little argon into obscurity!

Jem

[smogthemog]

I MUST try that sometime

Jim, What's the laser output from the ALC68?, i'm just wondering if that's why I've got holes in the back of my Pangolin tee shirt ... Just kidding, it blows my little argon into obscurity!

Jem

The one you had rear botty dealings with at the UKLEM Jem was a little ALC60 I have that I bought off of Simon (P1t8bull) and they are rated at around 80mW(ish).

This one is an ALC68 and as far as I know will run up to 3W maximum - I know it's very bright on the plastic of my conservatory frame anyway - Don't quote me on that though as I don't have a power meter to read it accurately, I am just going on what I have read. According to the meter on the front of the PSU on mine, it is pulling 23A at maximum.

[smogthemog]

Don't worry Jem, I don't have anything against you with all this beam targeting I seem to be doing

[Jem]

Don't worry Jem, I don't have anything against you with all this beam targeting I seem to be doing

No worries mate, I needed to top up my sun tan anyway

That sounds like a nice unit. I have to confess to having these uncontrollable desires to own a multi watt gas laser myself

Jem