Jeff Duntemann's Contrapositive Diary Rotating Header Image

Odd Lots

5 Comments

  1. William Meyer says:

    Interesting about the static issues. I have a big system in a fairly large Antec case, and have had no trouble with it. That said, as I started in hardware, and was an early adopter of CMOS logic, I think I have nothing I wear in my office that is not cotton. In winter, it does get pretty dry here, but I have not found any need for a humidifier, nor yet for any carpet treatment.

    Of course, I don’t come down here to the basement office in my socks, except for a very brief visit, as the carpet is on the slab. That is likely another reason for the low incidence of static.

    As to the Z68 you bought, I bought a similar one, about the same time you did. But I had an Ivy Bridge, and discovered that although the Z68 chipset is compatible, the BIOS installed was not, and to update the BIOS required a Sandy Bridge. Grrr… After evaluating the alternatives, I got a Z77 motherboard, and the Ivy Bridge was perfectly at home.

    I also have become a fan of the Zotac display cards, as I have been able to buy the ones with very large heat sinks and no fan, in lieu of the many cards which have fans that reliably die in 12-18 months, and for which replacements normally cannot be bought.

  2. Jack Smith says:

    Jeff:

    No learning exercise involved, but a CCFL inverter module is the easiest way to wind up with 1 KV or so. Mouser has one for $12 with 1.2KV output. Search Mouser with the term EL/CCFL Inverters & Accessories and you’ll find a wide range of input / output voltage abilities.

    If you want to build your own flyback converter, then inductor choice becomes important. Since E = L di/dt, more inductance = higher voltage and faster current turn on/off = higher voltage. However, larger inductors can have more distributed capacitance than lower value ones and hence the self-resonant frequency can limit di/dt. I think the CCFL power modules use a more conventional approach with a transformer and chopped input voltage rather than trying to do it with a one winding inductor.

    I wonder what you could get out of a piezo BBQ lighter – the raw voltage into an air gap is several KV, but coming up with a suitable rectifier may be challenging. The filter capacitor would have to have ultra low leakage – perhaps a Teflon dielectric of a high quality ceramic as there’s not a lot of current output.

    I’ve used Firefox for quite a while and the built-in PDF rendering engine still have a way to go to be acceptable. One problem I see frequently is that one page will render fine and the next page is blank, although the file displays perfectly with Adobe Acrobat. Another problem with FF’s rendering engine I’ve seen is font related. Mouser’s PDF catalog pages are a good example. As you zoom in to enlarge the page, some fonts render oddly and don’t scale. I’ve also found printing problems where a PDF document can’t be printed from the internal rendering engine.

  3. Jack Smith says:

    A CCFL output is AC, of course, at a frequency of some tens of KHz. A standard 1N4007 silicon rectifier will be suspect in that application due to long recovery time (buried charge keeps the diode conducting for some time after the input voltage flips from conducting to reverse bias. See my web page
    http://www.cliftonlaboratories.com/diode_turn-on_time.htm for a discussion and measured data.)

    There are fast silicon rectifiers and, of course, Schotkey diodes, so pay some attention to the turn-off time – often called “reverse recovery time” in the data sheets.

  4. Tom R. says:

    If you_Mix Camel_Case with under_scores can_you Call_it Ransom_Note?

  5. Andy Kowalczyk says:

    We can even fight about your reference to CamelCase – it should really be camelCase. You mistakenly referred to PascalCase.

Leave a Reply

Your email address will not be published.