Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!uunet!aplcomm!tedwards From: tedwards@aplcomm.JHUAPL.EDU (Edwards Thomas G S1A x8297) Newsgroups: sci.electronics Subject: Re: He-Ne tube power supplies Message-ID: <464@aplcomm.JHUAPL.EDU> Date: 26 Jun 91 13:38:05 GMT References: Reply-To: tedwards@aplcomm.jhuapl.edu (Edwards Thomas G S1A x8297 ) Distribution: sci.electronics Organization: JHU/APL, Laurel, MD Lines: 27 In article 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