The physical size suggests that it is one of the pulse rated energy storage
types
I have one same value almost exact same size made by Spraque and it is
labled for Photo Flash
I bought mine cheap when I believed that something for nothing and miracles
did exist.
That is a lot of capacitor in a small space to be conventional oil filled
Before I got a chance to use it I researched it and found the warnings "not
suitable for power supply filters"
Paul K0UYA
----- Original Message -----
From: "Pete Raymond" <n4kwpete@centurylink.net>
To: "Vic K2VCO" <vic@rakefet.com>; "Paul Kraemer" <elespe@lisco.com>
Cc: "Amps reflector" <amps@contesting.com>
Sent: Sunday, June 19, 2011 3:12 PM
Subject: Re: [Amps] Using an oil capacitor
>I have been following this thread with some concern. My oil filled
>capacitor measures
> 4 3/4" X 4 1/2" X 9 1/4", its markings are as follows. General Electric,
> Capacitor, Made in U.S.A.,
> 25F492, 25uf at 4000 VDC. How can one tell if this capacitor is suitable
> for a HV power supply.
> 73 Pete, N4KW
>
> ----- Original Message -----
> From: "Vic K2VCO" <vic@rakefet.com>
> To: "Paul Kraemer" <elespe@lisco.com>
> Cc: "Amps reflector" <amps@contesting.com>
> Sent: Sunday, June 19, 2011 1:34 PM
> Subject: Re: [Amps] Using an oil capacitor
>
>
>> Several respondents to my message have said the same thing. This
>> capacitor cannot be used
>> at its voltage rating in filter service and needs to be de-rated to about
>> half its spec'd
>> voltage in that case.
>>
>> I actually have two of these, so I could probably use them in series for
>> a 26.5 uf filter
>> capacitor. This would be adequate for a cw transmitter, although I'm not
>> sure if 6% ripple
>> wouldn't be audible on SSB. However, two capacitors make a very big
>> package, so I'm
>> thinking about going back to the conventional string of electrolytics.
>>
>> Any recommendations for a source of electrolytics? There are lots of
>> inexpensive ones on
>> ebay, but who knows if they are factory rejects!
>>
>> On 6/19/2011 10:10 AM, Paul Kraemer wrote:
>>> Vic BE CAREFUL. BE VERY CAREFUL!!!
>>> From the size and capacitance you describe it is probably an "energy
>>> storage capacitor"
>>> which is not suitable for power supply filter at even it's published
>>> ratings. You will be
>>> picking pieces of capacitor out of places you really don't want them.
>>> Paul K0UYA
>>>
>>> ----- Original Message ----- From: "Vic K2VCO" <vic@rakefet.com>
>>> To: "Amps reflector" <amps@contesting.com>
>>> Sent: Sunday, June 19, 2011 12:59 AM
>>> Subject: [Amps] Using an oil capacitor
>>>
>>>
>>>> I have an oil capacitor rated at 53 uf 3.5kv. I would like to use it in
>>>> a power supply
>>>> with a transformer delivering 2.4 kVAC. The peak voltage is thus close
>>>> to 3400V.
>>>>
>>>> I've never used an oil capacitor before. My line voltage is pretty
>>>> constant at 240V, but
>>>> if it were to rise to 250V, the voltage rating of the capacitor would
>>>> be exceeded. What
>>>> kind of safety factor do capacitors like this have?
>>>>
>>>> The capacitor is 4-1/2" x 4" x 10" and is marked CSI 4W308T. The CSI
>>>> website
>>>> <http://www.csicapacitors.com/csite/cms/149.htm> doesn't list this
>>>> particular one, but
>>>> other 3.5kV capacitors have similar part numbers. There's no detailed
>>>> spec. There is this
>>>> statement:
>>>>
>>>> "The WM series of capacitors is designed for general purpose pulse
>>>> applications in power
>>>> supplies for lasers, flash tubes and other capacitor discharge circuits
>>>> where moderate to
>>>> long life is required."
>>>>
>>>> I'm not sure if this is appropriate for power supply filter
>>>> application. Anybody familiar
>>>> with these?
>>>> --
>>>> Vic, K2VCO
>>>> Fresno CA
>>>> http://www.qsl.net/k2vco/
>>>> _______________________________________________
>>>> Amps mailing list
>>>> Amps@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>
>> --
>> Vic, K2VCO
>> Fresno CA
>> http://www.qsl.net/k2vco/
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>
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