[Amps] Choke input filters, design criteria?

[Boye Christensen]

Hi to All



I'll have designed Power supply in many years mostly Switch mode Power and 
in low power.



I decide to run some LT-spice simulation on it to find out what  what the 
best type ?



Design 4KV 1Amp and Vripple  pp 100V, Transformer loss included



1.   single phase with choke   Eff app 96%

2 .   3 phase no choke   Eff  app 96%

3.    single phase no choke Eff app 97%



This means 3 and 4 % out in heat out of  the Box.



As far I can se, there is not any difference in what  you are burning out in 
heat !

another case is about Power company will like the choke version because the 
crest factor.



Sense there is not big difference form the user this most be a  question 
about

Components prise/weight.








73 Boye OZ1CTK


----- Original Message ----- 
From: "Rob Atkinson" <ranchorobbo at gmail.com>
To: "Chris Wilson" <chris at chriswilson.tv>
Cc: "Amps" <amps at contesting.com>
Sent: Thursday, December 20, 2012 12:19 PM
Subject: Re: [Amps] Choke input filters, design criteria?


> yes the Henrys used resonant choke filters.  This helps explain it:
>
> http://www.qsl.net/i0jx/supply.html
>
> There was a nice article in QST in June 1946 about how to get the
> inductance of a "mystery" choke using some math, a multimeter, an AC
> microampere meter, and 120 v. service but since you have 240 you'd
> have to work with one side of that if the UK has neutral return (four
> wire service).
>
> If you can get access to QST on-line:  "How Much Inductance?  A simple
> method for measuring unknown filter chokes" by George H. Floyd W6OJK/2
> June 1946 QST p. 69 and 132.
>
> 73
>
> Rob
> K5UJ
>
> On Wed, Dec 19, 2012 at 8:14 AM, Chris Wilson <chris at chriswilson.tv> 
> wrote:
>>
>>
>>> 4 H is a bit low; 8 would be better.  Choke input filters are good for
>>> power supply loads that are fairly constant, i.e. modes like AM, FM,
>>> and RTTY.  Take a look at the designs used in earlier amps like the
>>> Heathkit HA-10 as something to work off of, also the power supply
>>> sections of 1 KW vacuum tube AM broadcast rigs.  Don't forget old
>>> handbooks, West Coast and ARRL from the '40s and '50s.  if you are in
>>> the UK perhaps RSGB has old handbooks with design criteria.  You could
>>> start with an 8 uF oil cap.  Let's assume you are going with 3.5 KV.
>>> Look for a cap rated for over 4; 4.5 KV or more is a good idea.
>>> Follow that with the choke and another oil cap like the first one at
>>> the input.  Don't fool around with electrolytics that will need to be
>>> replaced some day--this is a filter that will last as long as you do.
>>> Use the ratings of the choke as your guide.  Make sure the v. rating
>>> of the caps is working volts DC.  Stay away from energy discharge
>>> caps--a genuine filter cap will be bigger with sizable insulators on
>>> the contact lugs.
>>
>>> 73
>>> Rob
>>> K5UJ
>>
>>
>>
>>
>> 19/12/2012 14:03
>>
>> Thanks for the reply Rob. Is there a way to check the inductance of
>> another choke I have? The other one is bigger, and is from a 3 phase
>> supply for a Henry RF Generator. It gave just under 5kV at 1.5 amps.
>> Henry use the same part number in both the 3 and single phase versions
>> of the HV supply, but the single phase version uses 2 off 0.1uF
>> resonating capacitors, and a 4uF filter cap, with fairly low value
>> bleeder resistors. I believe these are to keep off load voltage in
>> check? The Henry schematics show both supplies using the same part
>> number of choke, but the 3 phase uses no resonance caps. The
>> schematics don't give the inductance though.
>>
>> I believe an HV choke needs measuring for inductance with DC on it,
>> for the purposes of use as a resonant choke, and making it resonant at
>> twice the mains frequency (100Hz in this case, after a full wave
>> bridge).
>>
>>
>>
>> --
>>        Best Regards,
>>                    Chris Wilson.
>>
>> _______________________________________________
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