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300W Resistive load?

H

Hammy

Jan 1, 1970
0
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.
 
J

Joerg

Jan 1, 1970
0
Hammy said:
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.
 
H

Hammy

Jan 1, 1970
0
Light bulbs? Two in series and then as many of those in parallel as needed.

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

Joerg

Jan 1, 1970
0
Hammy said:
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 :)

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 ...
 
H

Hammy

Jan 1, 1970
0
Please note that when cold a lightbulb is 1/10 the resistance.
So you supply may not start up at all.
Better take apart some electric heater.

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.
 
H

Hammy

Jan 1, 1970
0
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.
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 :)
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.;-)
 
J

Jamie

Jan 1, 1970
0
Hammy said:
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 ?
 
J

Joerg

Jan 1, 1970
0
Hammy said:
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.

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*.

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 :)
 
M

Martin Riddle

Jan 1, 1970
0
Joerg said:
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 :)

--


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

Cheers
 
J

Joerg

Jan 1, 1970
0
Martin said:
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 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.
 
J

Joerg

Jan 1, 1970
0
John said:
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 :)
 
M

Martin Riddle

Jan 1, 1970
0
John Ferrell said:
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.


John Ferrell W8CCW

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
 
J

Joerg

Jan 1, 1970
0
mpm said:
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..??? :)

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

Hammy

Jan 1, 1970
0
$10 is cheap? That's more than a six-pack of the good stuff.


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

Baron

Jan 1, 1970
0
Hammy Inscribed thus:
Agreed I'd need about fifty bucks worth of them, which is more then I
want to spend.

How about a couple of yards of electric fire bar element.
 
S

Sjouke Burry

Jan 1, 1970
0
Hammy said:
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.
wire a few car headlights together, each is 50-70W.
 
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.
Probably not quite. First, there'll be another election before then and
... well, we'll see.

The ban was put in place BO. I doubt the Republicans will have the guts to
turn that one around.
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

How about dual 30W filaments? Or perhaps 19/39(/58)? ;-)
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.

Try buying a real toilet. Well, if you don't live near a Canuckistani
HomeDespot.
 
H

Hammy

Jan 1, 1970
0
On Sat, 17 Jul 2010 17:21:39 -0500, "[email protected]"

[SNIP]
Try buying a real toilet. Well, if you don't live near a Canuckistani
HomeDespot.

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