300W Resistive load?
in [Design]
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From: Hammy on 17 Jul 2010 20:50 On Sat, 17 Jul 2010 17:06:10 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon(a)On-My-Web-Site.com> wrote: > >I've been known to take two sheets of copper clad, drill a grid of >holes and solder a hundred or so 2W resistors between the planes, put >a muffin fan on it and away you go... :-) > > ...Jim Thompson I'm starting to get a collection of 5 to 10W resistors but I dont have quite that many yet.;-)
From: Paul Hovnanian P.E. on 17 Jul 2010 22:03 Joerg wrote: > > Hammy wrote: > > On Sat, 17 Jul 2010 07:00:35 -0700, Joerg <invalid(a)invalid.invalid> > > wrote: > > > >> Hammy wrote: > >>> 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. > >> > >> Light bulbs? Two in series and then as many of those in parallel as needed. > > > > Sounds good one 60W bulb is about 200 ohms. ... > > At 200V each bulb gets only 100V so the resistance will be a little > lower. You could measure that if it must be precise. > > > ... I'll look around for some small cheap bulb mounts. > > 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 :-) Ceramic lamp sockets are cheap and available at any hardware store. And they are UL listed and approved for the purpose. No need to hack soething for which an easy solution exists. > 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 ... Just take every other bulb out of the bathroom fixture. And if the wifes makeup looks a bit funny afterwards, just keep your mouth shut. -- Paul Hovnanian mailto:Paul(a)Hovnanian.com ------------------------------------------------------------------ Bumper Sticker: Honk if you wish to meet Jesus.
From: kelly on 17 Jul 2010 23:40 "Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_(a)charter.net> wrote in message news:jHk0o.13295$wm1.384(a)newsfe01.iad... > Hammy wrote: > >> 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. > toster oven ? > > > Or the old replaceable electric jug / kettle elements.
From: Muzaffer Kal on 18 Jul 2010 00:05 On Sat, 17 Jul 2010 09:36:24 -0400, Hammy <spam(a)spam.com> wrote: >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. Ohmite makes all kinds of nice resistors. I used one of these to test my most recent power supplies: http://www.ohmite.com/cgi-bin/showpage.cgi?product=powrrib_series. -- Muzaffer Kal DSPIA INC. ASIC/FPGA Design Services http://www.dspia.com
From: Michael A. Terrell on 18 Jul 2010 04:06
mpm wrote: > > On Jul 17, 11:56 am, Joerg <inva...(a)invalid.invalid> wrote: > > Martin Riddle wrote: > > > "Joerg" <inva...(a)invalid.invalid> wrote in message > > >news:8ae3skFnekU1(a)mid.individual.net... > > >> Hammy wrote: > > >>> On Sat, 17 Jul 2010 07:37:28 -0700, Joerg <inva...(a)invalid.invalid> > > >>> wrote: > > > > >>>> Hammy wrote: > > >>>>> On Sat, 17 Jul 2010 07:00:35 -0700, Joerg <inva...(a)invalid.invalid> > > >>>>> wrote: > > > > >>>>>> Hammy wrote: > > >>>>>>> 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. > > >>>>>> Light bulbs? Two in series and then as many of those in parallel > > >>>>>> as needed. > > >>>>> Sounds good one 60W bulb is about 200 ohms. ... > > >>>> At 200V each bulb gets only 100V so the resistance will be a little > > >>>> lower. You could measure that if it must be precise. > > >>> 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. > > > > >> 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. > > > > >>>>> ... I'll look around for some small cheap bulb mounts. > > >>>> 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 :-) > > >>> Your taking all the fun out of this :-) > > > > >> The fun might come back when connecting the cold bulbs not two by two, > > >> but all at once. Tchk ... *POOF*. > > > > >>>> 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 ... > > >>> We call that a honey do list here.;-) > > > > >> 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 :-) > > > > >> -- > > > > > Better pick up extra incandescent bulbs, comes 2014, you wont be able to > > > get them here in the US. > > > > 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... > > > > As for frosted ones which were particularly frowned upon by regulators > > the page states "Bei Lampenwelt.de erhalten Sie matte Gl�hlampen noch > > aus gr��eren Restbest�nden. 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. > > > > -- > > Regards, Joerg > > > > http://www.analogconsultants.com/ > > > > "gmail" domain blocked because of excessive spam. > > Use another domain or send PM.- Hide quoted text - > > > > - Show quoted text - > > Yeah.... and then we'll have to deal with all the advertising hype for > those "innovative" companies that come up with a 39.9 W bulb and claim > some benefit derived therefrom. > > I wonder if this is how that extra 9/10th of a cent per gallon we pay > at the gas pump came into being..??? :) That was a woman's idea. :( -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge. |