[sci.electronics] He-Ne tube power supplies

mlyons@nmsu.edu (Michael Lyons) (06/26/91)

I was wondering if anyone out there happened to know of a good power
supply for a supposedly rated 1800 Volt He-Ne laser tube.  I picked it
up from a friend with no specs but am pretty sure that the voltage
rating is around 1.8kV.  I don't know the power output rating but would
guess a small milliwatt output.  
I have a home-built power supply that my friend had used previously
using a 555 timer circuit oscillator into a approx. 12 Volt primary
Xformer.  The output was then sent through a gutted Ford ignition coil
to give approx. 1.8 kVolts.  The problem is that the power supply was
sloppily built and I'm not sure if I want to go to all the trouble of
totally rebuilding it.  I think the design is alright but am wondering
if it would be cheaper to just get a new "made for He-Ne" laser power supply.  
Any suggestions would be greatly appreciated....

					Thanks,

					Mike Lyons << NMSU >>
					mlyons@nmsu.edu

tedwards@aplcomm.JHUAPL.EDU (Edwards Thomas G S1A x8297) (06/26/91)

In article <MLYONS.91Jun25222423@gauss.nmsu.edu> mlyons@nmsu.edu (Michael Lyons) writes:
>I was wondering if anyone out there happened to know of a good power
>supply for a supposedly rated 1800 Volt He-Ne laser tube.  I picked it

Meredith Instruments (P.O. box 1724 Glendale, AZ 85301 (602) 934-9387)
advertised a 12VDC input supply yielding 1.2-2.6KV @ 4.0-7.0 mA with a
10KV trigger for $75, and a 110VAC input supply for $95.

>I have a home-built power supply that my friend had used previously
>using a 555 timer circuit oscillator into a approx. 12 Volt primary
>Xformer.  The output was then sent through a gutted Ford ignition coil
>to give approx. 1.8 kVolts.  The problem is that the power supply was
>sloppily built and I'm not sure if I want to go to all the trouble of
>totally rebuilding it.

That depends on whether you want to dump $75 on a new supply.
It is probably worth it, as a supply of the type Meredith Instruments
builds will probably power any HeNe tube you would want to bring into
your home (up to at least 7mW).

Another way to build a supply is to have the 555 timer pulse current
(using a power transistor) into a slightly smaller xformer, and use
a voltage doubler circuit.  This saves one from having to find a
massive step up xformer, but requires one to find high voltage
diodes and capacitors.

-Tom