700w continuous for 48 hours 1500w max. http://www.parts-express.com/jantze...oil-toroidal-inductor-crossover-coil--255-808
No!
they're toroidal core , so no adequate for DC
what you can use is either with EI core (with luftspalt or just E open) or I core
they're toroidal core , so no adequate for DC
what you can use is either with EI core (with luftspalt or just E open) or I core
Would a pair of these be a good idea?
http://nl.mouser.com/Search/m_Produ...ufacturing/159ZL/&qs=HY6QdUiTBEx0jlhydDjqrA==
Bit lost to be honoust. Can not find suitable coils. Only the small cheap ones. All other have way to high dcr. 1 ohms plus.
These are also common mode?
By the way, is 2.2mh the way to go? Or does it have to be a other value
http://nl.mouser.com/Search/m_Produ...ufacturing/159ZL/&qs=HY6QdUiTBEx0jlhydDjqrA==
Bit lost to be honoust. Can not find suitable coils. Only the small cheap ones. All other have way to high dcr. 1 ohms plus.
These are also common mode?
By the way, is 2.2mh the way to go? Or does it have to be a other value
If you buy the wire thick enough and make the coil big enough you can get dcr down to any level achievable with cored coils.
If the hammonds are suitable for the job it would be a clc (pi) like this: 4x 22000uf 2.5mH coil 4x 22000uf 2x 2x 4.7uf
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The picture is a 5mH choke Zen Mod. Not the onewanted you to see ;-) if you scroll down it says max dc current 10A
An externally hosted image should be here but it was not working when we last tested it.
choke is good ; go for it , if your wallet is OK with it
if you can find air cored 2-2.5mH , under 0R2 Rdc and cheaper ..... you know what to do
Since this OP has found an answer, and the thread has since gone way OT, perhaps I can pose a different question: Are wire-wound the best resistor type for CRC filter? (Theoretically speaking and all other things being equal..).
I was thinking that the inductance inherent to wire-wound typs, would make it perfect for CRC. Even if the inductance is small, it should aid slightly in ripple reduction, giving an advantage over a MOX type.
Any opinions on this? 🙂
I was thinking that the inductance inherent to wire-wound typs, would make it perfect for CRC. Even if the inductance is small, it should aid slightly in ripple reduction, giving an advantage over a MOX type.
Any opinions on this? 🙂
you got it right , even if I have some doubts that you'll hear any difference between WW and MOX in that position
These resisters get plenty hot. For that reason I like to have many in parallel allowing lots of surface area for cooling. This is usually well beyond the actual total power dissipation necessary.
Where you may see other problems is if you have very high inrush current at turn on. Naturally the R in CRC doesn't see as much current as the first C but there will still be serious current going to the second C with <1 ohm Rs. This likely will cause an out of spec use of that resister if not selected properly. Most resister types handle momentary surges well and usually you can find this type of spec in the datasheet. Certain film resisters like Caddock's Vishay's etc will not survive very well to even somewhat momentary surges without permanent damage to the resister. Being that we rarely know the actual current profile at start up due to it's surge only as AC peaks greater than the existing charge and total peaks/time etc. it's just wise to use an over rated part or parts in this position
Where you may see other problems is if you have very high inrush current at turn on. Naturally the R in CRC doesn't see as much current as the first C but there will still be serious current going to the second C with <1 ohm Rs. This likely will cause an out of spec use of that resister if not selected properly. Most resister types handle momentary surges well and usually you can find this type of spec in the datasheet. Certain film resisters like Caddock's Vishay's etc will not survive very well to even somewhat momentary surges without permanent damage to the resister. Being that we rarely know the actual current profile at start up due to it's surge only as AC peaks greater than the existing charge and total peaks/time etc. it's just wise to use an over rated part or parts in this position
Thanks for the info guys. Have found some Ohmite 5w wirewound 0.5r that should do nicely. I realise the choice of resistors in CRC is not very critical (as long as they can take the heat), but always nice to get a better understanding of correct component choice - and I do like to obsess a bit on the details 😛
A single pulse transient of double the current rating of the resistors will instantaneously dissipate four (4) times the rated power of the resistor.
Metal Film are not usually specified for a transient this large.
Metal Oxide are a bit more robust for short term transients and may be OK.
Thick metal wire wound tend to be more robust still.
This is why I recommend series connected low value wire wound for soft start duty, rather than parallel connected high value resistors.
Not many resistor types are rated for a short term transient of double their normal rating.
eg for a rCRC.
The R for a continuous 100mA could be 0r5. It would dissipate 5mW
Any through hole resistor would easily take that and never get hot.
Look at Pmax next.
250mW 1r0||1r0.
each resistor is rated at 500mA (I=sqrt[P*R])
The total for the parallel combination is 1A.
A transient of 2Apk would be double the rated current for this 0r5, ½W
A 3W 0r5 has a rated current of 2.45A and double would be 4.9Apk
It is worth checking the maximum current rating of any resistors that have to pass infrequent transients, even though they do not add significant "heat" to the resistor due to very low duty.
Metal Film are not usually specified for a transient this large.
Metal Oxide are a bit more robust for short term transients and may be OK.
Thick metal wire wound tend to be more robust still.
This is why I recommend series connected low value wire wound for soft start duty, rather than parallel connected high value resistors.
Not many resistor types are rated for a short term transient of double their normal rating.
eg for a rCRC.
The R for a continuous 100mA could be 0r5. It would dissipate 5mW
Any through hole resistor would easily take that and never get hot.
Look at Pmax next.
250mW 1r0||1r0.
each resistor is rated at 500mA (I=sqrt[P*R])
The total for the parallel combination is 1A.
A transient of 2Apk would be double the rated current for this 0r5, ½W
A 3W 0r5 has a rated current of 2.45A and double would be 4.9Apk
It is worth checking the maximum current rating of any resistors that have to pass infrequent transients, even though they do not add significant "heat" to the resistor due to very low duty.
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