Difference between DC choke and inductor

Hello Folks!!

Is there any difference between DC choke and AC inductor??? I saw some rectifier with only choke filter. How the voltage is made ripple free then if there is no capacitor??

I read somewhere that recitfiers with DC choke filters need a very samll or even no capacitor. And the transformer VA can be reduced by using only choke filter.

Can anybody plz explain??


Regards~~

Kashif

"Choke" usually just refers to an inductor which mostly carries DC current, and blocks high frequency AC. "Inductor" is a general term, but some people only call something an inductor if it is only carrying AC current. The terminology isn't set in stone, so don't worry too much about it.

As for rectifiers with chokes, yes if you put a large choke on a diode rectifier it can reduce the crest factor of the current waveform, and act as a lowpass filter, which will decrease the necessary size of the filter capacitor. But usually the choke will be very big (at low frequencies), so from a size standpoint it doesn't really give any advantage. But it can be useful for increasing the power factor of the rectifier.

power inductor which has Isat and Irms requirement, the inductor can pass DC current, so in general we select Ni-Zn to make power inductor, we also say DC inductor.
choke is general name, there are single winding and two windings, e.g. PFC inductor and storage energy choke and filter and common mode choke in the range, for PFC inducor which has DC requested, filter and cmc pass AC current.

Additional to previous post this will be helpfull to see :



https://www.circuitstoday.com/series-inductor-filter

https://www.ehow.com/list_7502237_characteristics-inductor-dc-circuit.html

Oke thank you all..

Then how to select the DC choke value with other conditions like load voltage and current given. I know how to select parameters for LC filters. Is it same as designing LC filter components and then using only L and no capacitor???

Or there are some specific design rules for choke filters.?? It would be great If I could some document with details or some sample calculations for Dc choke for 3 phase bridge rectifier system.

Thnx and Regards~

Kashif

in general principle is same, V=L*di/dt=N*d(BS)/dt, all depend on your requirement, e.g. current and lnductance and dimension and DCR and dimension,first we suggest to use standard part, if not, the part must be customized, for difference inductor, has difference design, e.g. for common mode choke, we select high permeability core, UU or EE or ET or toroidal, SMD or pin through configuration, according to inductance and AL of core, get turns, get diameter of wire according to current.

@ szhighstar

I just need to calculate Inductor value in Henries under given ripple factor. Core selection, number of turns, etc is not my head ache. My question is how to calculate value of L for given ripple factor.
I studied about LC filters and how to calculate L and C values for given voltage and current ripple factors. I wonder if there is some special method to calculate L for DC choke filters. Or its same as calculating L value in LC filters???

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@ szhighstar

I just need to calculate Inductor value in Henries under given ripple factor. Core selection, number of turns, etc is not my head ache. My question is how to calculate value of L for given ripple factor.
I studied about LC filters and how to calculate L and C values for given voltage and current ripple factors. I wonder if there is some special method to calculate L for DC choke filters. Or its same as calculating L value in LC filters???

general principle is same, however for DC chock filter, we must consider Dc current, e.g. filter can not be saturation at DC current, and raising temperature is less than 40 degree at DC current,Bw=Bdc+Bac, L=0.4*π*N*N*Ae*10-8/Ig (H)