# 4H chokes?

M

#### Mathias

Jan 1, 1970
0
Dear ng,

I found an old design here
http://www.iop.org/EJ/abstract/0022-3735/3/2/420

for an arc lamp power supply that includes a pair of 4H chokes rated at
0.5A, 25R. As far as I can tell these would have to be gigantic, right?
I understand that chokes available today (at least below $20) are in the range of ~10mH. Do I miss something? Thanks, Mathias E #### Eeyore Jan 1, 1970 0 Mathias said: Dear ng, I found an old design here http://www.iop.org/EJ/abstract/0022-3735/3/2/420 for an arc lamp power supply that includes a pair of 4H chokes rated at 0.5A, 25R. As far as I can tell these would have to be gigantic, right? I understand that chokes available today (at least below$20) are in the
range of ~10mH. Do I miss something?

Given the resistance I don't suppose they carry that much current. Size willre
alte to current rating.

Check out the chokes used for smoothing the HT supplies in valve amps.

Graham

J

#### John Popelish

Jan 1, 1970
0
Mathias said:
Dear ng,

I found an old design here
http://www.iop.org/EJ/abstract/0022-3735/3/2/420

for an arc lamp power supply that includes a pair of 4H chokes rated at
0.5A, 25R. As far as I can tell these would have to be gigantic, right?

You wouldn't want to carry one all day.
I understand that chokes available today (at least below $20) are in the range of ~10mH. Do I miss something? They would be made with laminated iron cores, not ferrite or powdered iron. Here are some smaller examples. The weight goes up roughly in proportion to the stored energy, that is proportional to inductance, and proportional to the current squared. Pick one and scale it up. http://www.alliedelec.com/Search/Se...59U&sid=462019804C28E17F&N=-1248&SKU=967-0197 T #### Tam/WB2TT Jan 1, 1970 0 Mathias said: Dear ng, I found an old design here http://www.iop.org/EJ/abstract/0022-3735/3/2/420 for an arc lamp power supply that includes a pair of 4H chokes rated at 0.5A, 25R. As far as I can tell these would have to be gigantic, right? I understand that chokes available today (at least below$20) are in the
range of ~10mH. Do I miss something?

Thanks,
Mathias

They will weigh in the neighborhood of 2 - 5 pounds each. Good place to
start looking would be www.surplussales.com ; also, Fair Radio, and RF

M

Jan 1, 1970
0
...and why the h*ll should i !pay! $30 for some piddling document? well, that's a good question. If you're in a uni/library chances are you have free acess. Otherwise these fees are way too high, definitely. That's why I try to publish open acceess myself... J #### joseph2k Jan 1, 1970 0 Robert said: ...and why the h*ll should i !pay!$30 for some piddling document?
Totally agreed. The problem is that many traditional publishers have come
upon this idea for an income stream, neglecting the idea that most people
are willing to pay only for value received (which is usually less than a
tenth of the price asked for the various articles "offered"). Not to
mention the side issue that they are allergic to transactions of less than
US \$20.

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