I need a 4000watt 100uH powdered iron rod core or ferrite inductor. I don't think i am going to be able to buy these.
I guess what i will do is wind 10awg magnet wire round a powdered iron rod core or a ferrite core and measure the inductance till i get 100uH. Questions:
1. I need a meter that mesures inductance, is this ok?
http://cgi.ebay.com/Digital-LCR-Cap...ryZ25421QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
2. Approximatly how big should the core be? Where do i get a core? Can i just use any old solid iron round stock?
3. What pattern should i wind? One layer, bobin style?
btw it needs to be low resistance, like 0.08ohms.
thanks
I guess what i will do is wind 10awg magnet wire round a powdered iron rod core or a ferrite core and measure the inductance till i get 100uH. Questions:
1. I need a meter that mesures inductance, is this ok?
http://cgi.ebay.com/Digital-LCR-Cap...ryZ25421QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
2. Approximatly how big should the core be? Where do i get a core? Can i just use any old solid iron round stock?
3. What pattern should i wind? One layer, bobin style?
btw it needs to be low resistance, like 0.08ohms.
thanks
http://translate.google.com/transla...&hl=en&ie=UTF-8&oe=UTF-8&prev=/language_tools
You could build one of these.. I did and it works a charm, measures small caps too...
You could build one of these.. I did and it works a charm, measures small caps too...
Nordic,
I had built a LC meter with a PCB made by me. But it didn't worked. Now I will try this one.
Thanks for de link.
I had built a LC meter with a PCB made by me. But it didn't worked. Now I will try this one.
Thanks for de link.
Its for a large power filter, large.
I don't mind buying a meter, i will likely use it alot. Am i fine with a handheld?
I don't mind buying a meter, i will likely use it alot. Am i fine with a handheld?
Perhaps it would help to specify the exact requirements, 4000watts doesn't tell us much (you don't really want an inductor that dissipates 4000W do you?). "Large" is pretty ambiguous as well.. even assuming it's a 4000W supply is it 4 volts at 1000 amps, 4000 volts at 1 amp? Both would be 4000W but would require quite different inductors.
So, what current and voltage are we talking?
Depending on what you actually need, there may be something commercially available. Otherwise, you'll need to figure the right wire size for the current, make sure the insulation will handle the voltage, and then find some way to calculate at least roughly how many turns you'll need for a particular core. Measuring as you go will be tricky, where do you make your meter connections, scape off some insulation every few turns? That wouldn't be very acceptable. I'd think your best bet would be to wind enough to be sure you're past 100uH, then carefully trim off bits to work back down to that value.
So, what current and voltage are we talking?
Depending on what you actually need, there may be something commercially available. Otherwise, you'll need to figure the right wire size for the current, make sure the insulation will handle the voltage, and then find some way to calculate at least roughly how many turns you'll need for a particular core. Measuring as you go will be tricky, where do you make your meter connections, scape off some insulation every few turns? That wouldn't be very acceptable. I'd think your best bet would be to wind enough to be sure you're past 100uH, then carefully trim off bits to work back down to that value.
Its for 120V at around 30 or 40 amps.
http://www.geocities.com/jonrisch/surge.htm
Thats what its for.
http://www.geocities.com/jonrisch/surge.htm
Thats what its for.
8AWG wire and a iron rod 1" in diameter sound good? I am going to get the iron off mcmaster carr. They have cast gray iron and ductile iron, what sould i use.
Iron rod as a core is a really bad idea...
I'd go for an air-core at that kind of capacity. 30seconds with Google turned up this page:
http://www.dpg.devry.edu/~akim/new/inductor.htm
- and 2mins of playing with numbers produced this:
Inductance 0.1 mH
DC Resistance 0.02 Ohms
Wire Gauge 8 AWG
Wire Diameter 128.5 mils (1 mil = .001 in)
Coil Length 1 in
Coil Inner Diameter 3 in
Coil Outer Diameter 4.03 in
Average Turn Diameter 3.37 in
Wire Length 27.36 feet
Copper Weight 1.37 pounds
Turns 31
Levels 3.98
Turns/Level 7.78
Good enough? Bear in mind that at 40A, this coil would dissipate (40*40*0.02) = 32W. You might want to make the thing even larger diameter for better heat dissipation. And to have a think about what you really want to achieve with such a beast!
I'd go for an air-core at that kind of capacity. 30seconds with Google turned up this page:
http://www.dpg.devry.edu/~akim/new/inductor.htm
- and 2mins of playing with numbers produced this:
Inductance 0.1 mH
DC Resistance 0.02 Ohms
Wire Gauge 8 AWG
Wire Diameter 128.5 mils (1 mil = .001 in)
Coil Length 1 in
Coil Inner Diameter 3 in
Coil Outer Diameter 4.03 in
Average Turn Diameter 3.37 in
Wire Length 27.36 feet
Copper Weight 1.37 pounds
Turns 31
Levels 3.98
Turns/Level 7.78
Good enough? Bear in mind that at 40A, this coil would dissipate (40*40*0.02) = 32W. You might want to make the thing even larger diameter for better heat dissipation. And to have a think about what you really want to achieve with such a beast!
Hi,
if an air cored coil is OK, then here is some data:
wire diam...........3mm........4mm
bobbin diam.......43.5mm....55mm
bobbin width.....20.7mm.....26.2mm
coil height.........18.6mm....23.6mm
o/a diam...........80.8mm....102.1mm
copper weight...530gms...1070gms
resistance..........0r02.........0r013
turn/layer...........6.9............6.5
layers................6.2............5.9
total turns..........42.9.........38.6
resistive power...32W........21W
@ 40Amps
using the formula L=7.87M^2N^2/(3M+9B+10C)
where C=coil height
B=coil width
M=mean coil diameter
lowest resistance and highest Q when 3M=9B=10C (a squarish coil)
if an air cored coil is OK, then here is some data:
wire diam...........3mm........4mm
bobbin diam.......43.5mm....55mm
bobbin width.....20.7mm.....26.2mm
coil height.........18.6mm....23.6mm
o/a diam...........80.8mm....102.1mm
copper weight...530gms...1070gms
resistance..........0r02.........0r013
turn/layer...........6.9............6.5
layers................6.2............5.9
total turns..........42.9.........38.6
resistive power...32W........21W
@ 40Amps
using the formula L=7.87M^2N^2/(3M+9B+10C)
where C=coil height
B=coil width
M=mean coil diameter
lowest resistance and highest Q when 3M=9B=10C (a squarish coil)
Hi
I looked at that AC filter in the link, and wouldn't recommend it at all. I not sure what exactly you want to filter using that design. What you probably really want is a common mode filter and a diffential filter together ie 2 stages with 3 inductors total. A common mode inductor is 2 windings on the same core. That filter in the link is just a differential design, with extra Y caps to ground, not really effective for common mode without a series impedance. IMO- Common mode is really where the problems are needing the most attention.
If given a choice what to build between the 2 stages I would build a common mode inductor with 2 loosely coupled windings and use it in place of L1 and L2 in the design link. You could use a split bobbin along with E powdered iron for the core material. Magnetics Inc. is what we've used for this.
edit> see link for filter topology http://www.cor.com/Series/PowerLine/SK/
I looked at that AC filter in the link, and wouldn't recommend it at all. I not sure what exactly you want to filter using that design. What you probably really want is a common mode filter and a diffential filter together ie 2 stages with 3 inductors total. A common mode inductor is 2 windings on the same core. That filter in the link is just a differential design, with extra Y caps to ground, not really effective for common mode without a series impedance. IMO- Common mode is really where the problems are needing the most attention.
If given a choice what to build between the 2 stages I would build a common mode inductor with 2 loosely coupled windings and use it in place of L1 and L2 in the design link. You could use a split bobbin along with E powdered iron for the core material. Magnetics Inc. is what we've used for this.
edit> see link for filter topology http://www.cor.com/Series/PowerLine/SK/
So one of these http://www.cor.com/Series/PowerLine/SK/ after an isolation transformer would work better than the design on this site:
http://www.geocities.com/jonrisch/surge.htm
I don't know if an aired cored inductor would work. Hard to wind too, need a winding machine to do i nice job but 8awg is too big for most winders.
What should i do? I would like really clean power.
http://www.geocities.com/jonrisch/surge.htm
I don't know if an aired cored inductor would work. Hard to wind too, need a winding machine to do i nice job but 8awg is too big for most winders.
What should i do? I would like really clean power.
Read this app note for common mode chokes from Magnetics Inc.
http://www.mag-inc.com/pdf/FC-S2.pdf
As I said before, you want to use an E type core with a split bobbin. Mag Inc won't carry bobbins usually, but their distributors will.
Or else just simply buy the Corcom part. It's UL approved so you are covered.
http://www.mag-inc.com/pdf/FC-S2.pdf
As I said before, you want to use an E type core with a split bobbin. Mag Inc won't carry bobbins usually, but their distributors will.
Or else just simply buy the Corcom part. It's UL approved so you are covered.
Thats sounds hard and complicated. Is it just going to like a EI transformer with no secondary wire.
How did i know this would not be as winding some wire around some iron.
I would go runing and jumping threw the park like a crazy man if i ever found a good source of iron...
How did i know this would not be as winding some wire around some iron.
I would go runing and jumping threw the park like a crazy man if i ever found a good source of iron...
Software - I have not used this. I normally use a notepad and calc.
http://www.mag-inc.com/software/cmf.asp
More Iron and shapes than you can shake a stick at
http://www.mag-inc.com/ferrites/ferrite_power_shapes.asp
http://www.mag-inc.com/software/cmf.asp
More Iron and shapes than you can shake a stick at
http://www.mag-inc.com/ferrites/ferrite_power_shapes.asp
What are you building that takes 30-40A at 120V, and is your fire insurance paid up?
Why not go to 240, that would halve your current and quarter your I2R losses (for instance, that 32W heating up your choke would be reduced to 8W).
Why not go to 240, that would halve your current and quarter your I2R losses (for instance, that 32W heating up your choke would be reduced to 8W).
Wow, they have lots of laminations, i can't use ferrite in output transformers right?
I am stepping down 240V to 120V, i achieve isolation & load both legs of the power coming in. Then i plan to filter the 120V.
Triamping with tube mono blocks uses lots of electricity, not to mention, CD, DVD, Switch, elecrostat bias, digital equalizer, tube preamp, active crossover, projector, massive 60 chip DAC, turntable, cable box, tuner. It all seams to add up to a blown 20A fuse and a oh no so i figure i mite as well overbuild.
I am stepping down 240V to 120V, i achieve isolation & load both legs of the power coming in. Then i plan to filter the 120V.
Triamping with tube mono blocks uses lots of electricity, not to mention, CD, DVD, Switch, elecrostat bias, digital equalizer, tube preamp, active crossover, projector, massive 60 chip DAC, turntable, cable box, tuner. It all seams to add up to a blown 20A fuse and a oh no so i figure i mite as well overbuild.
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