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300W Resistive load?

Discussion in 'Electronic Design' started by Hammy, Jul 17, 2010.

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  1. Hammy

    Hammy Guest

    What is something cheap and simple that can be used to dissapate 300W
    on a 200Vdc bus. I'm trying to think of something I could maybe pick
    up at a local homedepot or similiar.

    I need a 300W load to test out my PFC.
     
  2. Joerg

    Joerg Guest


    Light bulbs? Two in series and then as many of those in parallel as needed.
     
  3. Hammy

    Hammy Guest

    Sounds good one 60W bulb is about 200 ohms.I'll look around for some
    small cheap bulb mounts.
     
  4. Joerg

    Joerg Guest


    At 200V each bulb gets only 100V so the resistance will be a little
    lower. You could measure that if it must be precise.


    You can also solder to them. If careful they can later still be used for
    their intended purpose. But make sure you place them onto a heat
    resistant surface during the test :)

    Good news is you may not even have to drive all the way to Home Depot.
    Supermarkets also have a variety of them. Of course, then your wife
    might hand you a lengthy "while you are there anyhow" list and you don't
    get to look at all the new power tools, barbecues and stuff. Man's toy
    store ...
     
  5. Hammy

    Hammy Guest

    I have NTC inrush limiters for that.

    It should also take some ms for the controller to start-up during this
    time the bulbs would be supplied from a rectified line, should heat
    them up enough.

    The controller is supposed to hiccup anyways in the event of a short.

    But you are right if I do run into start-up problems I'll look into
    that.
     
  6. Hammy

    Hammy Guest

    I don't need high precision if I can test at even 80% rated load and
    maybe do some pulse test and off course use a CT to check the input
    current I'll be happy.
    Your taking all the fun out of this :)
    We call that a honey do list here.;-)
     
  7. Jamie

    Jamie Guest

    toster oven ?
     
  8. Joerg

    Joerg Guest


    Well, just wanted to mention that because when at undervoltage the bulbs
    will present a higher load. Also, when you start any kind of converter
    from zero they will almost look like a short initially. Same if you
    connect a cold bulb (cold filament) to a running converter. It's not
    like a power resistor.

    The fun might come back when connecting the cold bulbs not two by two,
    but all at once. Tchk ... *POOF*.

    Nah, a honey-do list isn't grocery shooping, it's when the missus wants
    you to get that tree stump out over yonder, and it's 105F :)
     

  9. Better pick up extra incandescent bulbs, comes 2014, you wont be able to
    get them here in the US.

    Cheers
     
  10. Joerg

    Joerg Guest

    Probably not quite. First, there'll be another election before then and
    .... well, we'll see.

    Then the ban extends down to 40W AFAIK. I am sure some clever business
    will start selling 39W light bulbs. The basic idea seems to come from
    Poland:

    http://mojapolskadomowa.blox.pl/resource/zarwka99w.jpg

    A gray market might also develop. In Germany where 100W bulbs have been
    banned long since they are still happily selling them:

    http://www.lampenwelt.de/Leuchtmittel/Gluehlampen/E27-Gluehlampen/E27-15W-100W-Gluehlampe-matt.html

    As for frosted ones which were particularly frowned upon by regulators
    the page states "Bei Lampenwelt.de erhalten Sie matte Glühlampen noch
    aus größeren Restbeständen. Lieferung sofort ab Lager solange der Vorrat
    reicht!" which means " ... frosted light bulbs from large overstock.
    Prompt delivery as long as stock lasts!". For some reason it must have
    lasted more than a year by now :)

    Ban, compliance, two different things it seems.
     
  11. Joerg

    Joerg Guest

    Problem is, with a 200V application you'll need two and that gets to be
    expensive. Same with toaster ovens and stuff.

    Unless you had a use for the items later, such as raising chickens :)
     
  12. Used these before for a 5KW load.
    Ceramic Cone heaters, can also get them straight vs cone.
    example: <http://www.akinsun.com/Accessories4.html>

    Cheers
     
  13. Joerg

    Joerg Guest

    Or the $999.95 laptop. It's all about making a buck :)
     
  14. Tim Williams

    Tim Williams Guest

  15. Joerg

    Joerg Guest

  16. Hammy

    Hammy Guest


    Agreed I'd need about fifty bucks worth of them, which is more then I
    want to spend.
     
  17. Baron

    Baron Guest

    Hammy Inscribed thus:
    How about a couple of yards of electric fire bar element.
     
  18. Sjouke Burry

    Sjouke Burry Guest

    wire a few car headlights together, each is 50-70W.
     
  19. Guest

    I already have a couple hundred clear 60W bulbs. I'll buy another couple of
    hundred by 2012, which is when the ban goes into effect.
    The ban was put in place BO. I doubt the Republicans will have the guts to
    turn that one around.
    How about dual 30W filaments? Or perhaps 19/39(/58)? ;-)
    Try buying a real toilet. Well, if you don't live near a Canuckistani
    HomeDespot.
     
  20. Hammy

    Hammy Guest

    On Sat, 17 Jul 2010 17:21:39 -0500, ""

    [SNIP]
    Yea we have Mohawks running bootleg booze and smokes across the lake
    and yanks smuggling toilets back the other way.;-)
     
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