Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

How to Register on LPF | LPF Donations

AC Power Supply (HeNe)

R

Roam

0
Joined
Nov 21, 2011
Messages
106
Points
18
I've got this HeNe power supply that runs off the mains. But the problem is it takes 115 Vac (designed for the US mains where you have 120 volts). Here in the southern hemisphere electricity is distributed as 50 Hz ac at ~230 V.

I think the psu has some kind of rectifier to get dc, and then perhaps a boost converter after that. But I wouldn't know what are their tolerance/compliance. So what is likely to happen if I connect this to a tube and switch it on?

Is it very risky to try the psu on the tubes?? (I don't want to ruin the tubes, or the psu)
 





Can you not use one leg of the 220VAC? One lead (going to ground) should be 120v volts, more or less. And the 50Hz versus the 60Hz should not be an issue.

If you're afraid of screwing something up, it will likely be the power supply and not the tube. If you are squeemish, power just the PSU without the HeNe connected for a few minutes. If it doesn't heat up or explode, you can feel confident it will not hurt the tube.
 
That's not the way it works in other countries, pschlosser. It is 220V to neutral.
 
Where are you located? HeNe PSU's draw very little, so you could get away with the cheapest smallest stepdown transformer and it'll be fine.

50VA 240VAC to 115VAC Stepdown Transformer - Jaycar Electronics

Not the cheapest, but if you're in NZ or Aus it's probably local, though you could get something cheaper from eBay.

Connecting it straight to 220-240V will result in damage.

Alternatively you could find a 12V HeNe PSU.
 
Last edited:
Depending on the actual type of HeNe PS you have there
may be a wire available that can be connected to 220VAC.

Some HeNe encapsulated PSs have universal 110/220 VAC
inputs.

Maybe a clear picture of your PS would help...



Jerry
 
Last edited:
Thanx a lot for all the responses. :yh:

Lasersbee, it's a compact brick style PS. It operates from the 115 volt ac line, the output is 1800-2600 volts @ 6 mA. I've attached a photo.

Pschlosser, not sure if that works, I think it's 230 V with respect to ground/zero voltage reference node. :confused:

I think I'll opt for the transformer option. I don't want to run the risk of damaging the ps.
Things, the Jaycar transformer's input doesn't have the same socket type as the ps. The cheap transformers on ebay have the same problem. What kind of adapter do I need?
 

Attachments

  • Untitled-1.jpg
    Untitled-1.jpg
    145.2 KB · Views: 128
Last edited:
Can you get a close-up of the label on the PSU?

Peace,
dave
 
Unless it has a second white wire hiding somewhere, that's 120V only. Between white and yellow is 120V, and between white and white is 240V.
 
Last edited:
Cyparagon said:
Unless it has a second white wire hiding somewhere, that's 120V only. Between white and yellow is 120V, and between white and white is 240V.
Click to expand...

Yep that all I see yellow,white,green and the purple loop wire. And the 120 volt cord attached to line input on the PSU. A close up picture on the PSU label mite help?
 
It could be possible that the loop of wire is the voltage doubler link. Some switching power supplies (PC supplies too) have a link that you short for 120V operation and leave open for 240V operation. We can't know for sure on your PSU unless we have the manual
 
djQUAN said:
It could be possible that the loop of wire is the voltage doubler link. Some switching power supplies (PC supplies too) have a link that you short for 120V operation and leave open for 240V operation. We can't know for sure on your PSU unless we have the manual
Click to expand...

Nope. I forget what it's called but it cut the power to the PSU. I am sure someone will chime in it's use.
 
Sure, here is a close up of the label:

xags.jpg


Nop, there's just one white, a yellow, a green, and a violet loop (which I think has to be cut if want to defeat delay). So this is a 120 volt only?
 
Cyparagon said:
That's not the way it works in other countries, pschlosser. It is 220V to neutral.
Click to expand...

Doh. Cyp corrects me, again. Thank you. :)

Roam said:
Nop, there's just one white, a yellow, a green, and a violet loop (which I think has to be cut if want to defeat delay). So this is a 120 volt only?
Click to expand...

Yes, I think you're right, the PSU is 120V only. :(

The step-down transformer idea others have suggested could be your lowest cost option. (before shipping)
 
You must log in or register to reply here.


Back
Top