300W Resistive load?
in [Design]
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From: Joerg on 17 Jul 2010 12:25 Hammy wrote: > On Sat, 17 Jul 2010 07:37:28 -0700, Joerg <invalid(a)invalid.invalid> > 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 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 :-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Martin Riddle on 17 Jul 2010 12:36 "Joerg" <invalid(a)invalid.invalid> wrote in message news:8ae3skFnekU1(a)mid.individual.net... > Hammy wrote: >> On Sat, 17 Jul 2010 07:37:28 -0700, Joerg <invalid(a)invalid.invalid> >> 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 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. Cheers
From: John Ferrell on 17 Jul 2010 12:43 Small electric heater with switch able power level. I don't know about now, but in the distant past hardware stores sold heating elements that screwed into porcelain light sockets. The intended use was for chicken incubators. 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. John Ferrell W8CCW
From: Joerg on 17 Jul 2010 12:56 Martin Riddle wrote: > "Joerg" <invalid(a)invalid.invalid> wrote in message > news:8ae3skFnekU1(a)mid.individual.net... >> Hammy wrote: >>> On Sat, 17 Jul 2010 07:37:28 -0700, Joerg <invalid(a)invalid.invalid> >>> 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 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/E27-15W-100W-Gluehlampe-matt.html As for frosted ones which were particularly frowned upon by regulators the page states "Bei Lampenwelt.de erhalten Sie matte 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.
From: Joerg on 17 Jul 2010 13:01
John Ferrell wrote: > Small electric heater with switch able power level. > > I don't know about now, but in the distant past hardware stores sold > heating elements that screwed into porcelain light sockets. The > intended use was for chicken incubators. > 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 :-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |