HeNe for £30 on eBay

Just stumbled across these 20mW HeNe lasers on my daily hunt for bargain lasers.

http://cgi.ebay.co.uk/2-RED-HELIUM-...3286.c0.m14&_trkparms=66:2|65:1|39:1|240:1318

Looks pretty cheap if anyone wants them.

Actually what's being sold isn't two HeNe lasers but two HeNe laser tubes which "can be refilled, if you search the internet you will find somebody who has the skills and equipment to do this".

I wouldn't count on getting more than two empty glass tubes and a broken power board.

A 1200VAC power source is required .

Cyparagon said:

A 1200VAC power source is required   .

Click to expand...

No, just a transformer. Cheap stuff.

Yeah.... a transformer that outputs 1200VAC..... :
Not cheap... :'(

What you get is the Voltage Multiplier PCBs... (and probably empty tubes)... :-?
These HeNe 10mW tubes kick-start with 10,000 to 20,000 VDC...

Jerry

lasersbee said:

Yeah.... a transformer that outputs 1200VAC..... :
Not cheap... :'(

What you get is the Voltage Multiplier PCBs... (and probably empty tubes)... :-?
These HeNe 10mW tubes kick-start with 10,000 to 20,000 VDC...

Jerry

Click to expand...

1200V at 0,054A means 65W, which means you will need 240V at less than 500mA (about 300mA) in the primary of the transformer.

1200/240 means a 5/1 ratio, so a 240 to 48V @500mA transformer in reverse will do the job, if i'm not missing something. And those are pretty cheap as far as I know...

erdabyz said:

[quote author=lasersbee link=1237374984/0#4 date=1237386246]Yeah.... a transformer that outputs 1200VAC..... :
Not cheap... :'(

What you get is the Voltage Multiplier PCBs... (and probably empty tubes)... :-?
These HeNe 10mW tubes kick-start with 10,000 to 20,000 VDC...

Jerry

Click to expand...

1200V at 0,054A means 65W, which means you will need 240V at less than 500mA (about 300mA) in the primary of the transformer.

1200/240 means a 5/1 ratio, so a 240 to 48V @500mA transformer in reverse will do the job, if i'm not missing something. And those are pretty cheap as far as I know...


[/quote]
Yeah... what you are missing is the insulation rating of the Xfo windings... you are putting 240vac on
the output windings rated at 48vac and you are subjecting the input wings to a 1200vac voltage
when they are rated for 240vac...

Your cheap solution could burn down your home if it doesn't just blow after shorting out the
coil windings....  :'(

Yeah... I know... it looked good on paper.... :

Jerry

lasersbee said:

[quote author=erdabyz link=1237374984/0#5 date=1237387919][quote author=lasersbee link=1237374984/0#4 date=1237386246]Yeah.... a transformer that outputs 1200VAC..... :
Not cheap... :'(

What you get is the Voltage Multiplier PCBs... (and probably empty tubes)... :-?
These HeNe 10mW tubes kick-start with 10,000 to 20,000 VDC...

Jerry

Click to expand...

1200V at 0,054A means 65W, which means you will need 240V at less than 500mA (about 300mA) in the primary of the transformer.

1200/240 means a 5/1 ratio, so a 240 to 48V @500mA transformer in reverse will do the job, if i'm not missing something. And those are pretty cheap as far as I know...


[/quote]
Yeah... what you are missing is the insulation rating of the Xfo windings... you are putting 240vac on
the output windings rated at 48vac and you are subjecting the input wings to a 1200vac voltage
when they are rated for 240vac...

Your cheap solution could burn down your home if it doesn't just blow after shorting out the
coil windings....  :'(

Yeah... I know... it looked good on paper.... :

Jerry[/quote]

Yeah... i've been partially owned...

It wouldn't probably burn nor explode, maybe just a spark and some smoke...
With the proper protection devices (which at least here all houses have) i think it would be worth to try... of course outside.

Once i accidentally short-circuited the AC input of a great PSU i had... because i dropped a metallic thing and...
But the only thing that happened was a big spark and some "burning" inside the PSU, enought to trash it...
But it didn't exploded or burned.

Early in feb, i dropped vodka on my usb plug. Hopefully i had the idea to unplug the power extension.
I got a burn on both finger through.

110AC, 5V @2Amp
I felt like i was loosing energy( kind of when they take blood sample).
I woke up a minute later with a third degree burn..

When did He/Ne's start using AC outputs? Arent they all DC?

Rangedunits said:

Early in feb, i dropped vodka on my usb plug. Hopefully i had the idea to unplug the power extension.
I got a burn on both finger through.

110AC,  5V @2Amp
I felt like i was loosing energy( kind of when they take blood sample).
I woke up a minute later with a third degree burn..

Click to expand...

You must be one salty guy to get zapped by 5vdc

WannaBurn said:

When did He/Ne's start using AC outputs? Arent they all DC?

Click to expand...

Hey wannaburn....
you can use AC to produce the High Voltage DC required to start and sustain
the HeNe tubes...


Jerry

lasersbee said:

[quote author=WannaBurn link=1237374984/0#9 date=1237422084]When did He/Ne's start using AC outputs? Arent they all DC?

Click to expand...

Hey wannaburn....
   you can use AC to produce the High Voltage DC required to start and sustain
the HeNe tubes...  


Jerry[/quote]


Ive never tried anything AC with my tubes, only DC. I have used DC flybacks from say a PC monitor. I know those tubes can be finicky to get going, and wont maintain if the power is too rough.

I just check my 5mW Melles tube and P/S, and the input is 24-28vdc with an output of 1800vdc as well (typical)

I guess this falls under the 'learn something new' category

Many HeNe PSU's run off of AC input. The output is still DC.

Peace,
dave

daguin said:

Many HeNe PSU's run off of AC input.  The output is still DC.

Peace,
dave

Click to expand...

Thats what I thought. There was mention of VAC out... That I have never heard of. Those PSU's sure bite like an AC source though :-/

That was because... the auction included the DC Voltage Multiplier PCBs...
but they required a Transformer that was able to output 1200vac into the
DC Multiplier PCBs...

OK wannaburn.... that's enough beer for you..... ;D ;D

They bite because it is pulsed DC....


Kerry

lasersbee said:

That was because... the auction included the DC Voltage Multiplier PCBs...
but they required a Transformer that was able to output 1200vac into the
DC Multiplier PCBs...

OK wannaburn.... that's enough beer for you..... ;D ;D

They bite because it is pulsed DC....


Kerry

Click to expand...

LOLOLOL, enuff beer for me? okay 'Kerry' : ;D ;D ;D I do see the point though