[TCML] Looking for pulse cap
Ken or Doris Herrick
kchdlh at sonic.net
Thu Sep 17 12:29:44 MDT 2009
You're right, Herr Zapp. Do the right thing; if for no other reason,
it'll make you feel better about yourself.
KCH
Quarkster wrote:
> <div class="moz-text-flowed" style="font-family: -moz-fixed">Matt -
>
> Actually, profit margins for "commodity" component manufacturers are
> very, very small. If you were to compare the profit margins for every
> link in the component distribution chain, you will almost always find
> that the MANUFACTURER has the lowest profit margins, frequently
> operating at only a few percentage points of gross revenue. If you are
> offering a sole-source proprietary component, margins can be quite a
> bit better, but for commodity resistors, capacitors, etc. margins are
> universally low.
>
> When a domestic manufacturer approaches a zero-profit margin situation
> with a particular product, he has several options:
> 1. Discontinue the product;
> 2. Move the production of the product to a location where
> manufacturing costs are (temporarily) lower (Mexico, China, etc).
> 3. Reduce material costs by using lower-quality materials, and
> possibly reducing product performance margins (product still "meets"
> specs, but is not as robust).
>
> In the case of C-D capacitors, as Tesla coil builders we certainly
> don't want options #1 or #3 to occur.
>
> As Americans, we shouldn't want option #2 to occur.
>
> I may be in the minority, but the approach of "lying to get free
> stuff" is just fraudulent and doesn't seem be the right way to conduct
> your business.
>
> (A slightly different scenario, but I had the same gut response when
> immediately after the Gulf hurricane disasters, some list members were
> gleefully gloating about all the "free" pole pigs that they could
> simply pick up and haul off, not giving a damn about who might suffer
> in the long run.)
>
> It's just not ethical.
>
> (End of rant.)
>
> Herr Zapp
> ----- Original Message ----- From: <Mddeming at aol.com>
> To: <tesla at pupman.com>
> Sent: Wednesday, September 16, 2009 11:20 PM
> Subject: Re: [TCML] Looking for pulse cap
>
>
>>
>>
>> Even hundreds of samples constitute a miniscule part of their
>> advertising
>> budget. Hundreds of thousands are spent each year to get their name
>> out in
>> front of potential buyers. Even if they weren't, when I think of
>> affecting
>> the bottom line of a multimillion-dollar corporation by a dollar or
>> so I
>> can only say:
>> Pffblblblblpppttttt!!
>>
>> Matt D.
>>
>>
>> In a message dated 9/16/2009 10:25:21 P.M. Eastern Daylight Time,
>> quarkster at att.net writes:
>>
>>
>> Shannon -
>>
>> Sorry, but in my opinion presenting a manufacturer with a totally
>> fraudulent
>> "manufacturing plan" to try and "trick" him into providing free
>> samples is
>> completely unethical. It may even be illegal.
>>
>> All "sample" parts provided by manufacturers cost money to
>> fabricate, test
>> and ship. Manufacturers provide samples to Engineers and product
>> developers
>> to stimulate usage of the parts in real-world products, which
>> results in
>> volume sales of that component and profit for the company. By lying
>> to a
>> manufacturer about your bogus "product requirements" and potential
>> future
>> sales, and obtaining samples based on those fraudulent claims, you are
>> negatively affecting that manufacturer's bottom line.
>>
>> American manufacturers are slowly being squeezed out of business by
>> many
>> factors. Don't add to their problems by cheating. Unfortunately, most
>> component manufacturers don't really have the resources to check the
>> legitimacy of sample requests.
>>
>> If you REALLY have an interesting or unique application for a
>> manufacturer's
>> components, talk to someone in the company's Marketing department,
>> and let
>> them know that while your project is simply an amateur experiment,
>> it may
>> be
>> an interesting new application for their product, that you would
>> like them
>> to consider helping to support your project, and that you will send
>> them a
>> report and photos of the completed widget. If they agree, great. If
>> not,
>> then just save your pennies and buy parts like the rest of us.
>>
>> If you can't affort to purchase the parts for your Tesla projects,
>> take up
>> a
>> different hobby.
>>
>> Regards,
>> Herr Zapp
>> ----- Original Message ----- From: "Weinhold Shannon L"
>> <Shannon.L.Weinhold at doc.state.or.us>
>> To: "Tesla Coil Mailing List" <tesla at pupman.com>
>> Sent: Wednesday, September 16, 2009 10:04 AM
>> Subject: RE: [TCML] Looking for pulse cap
>>
>>
>> You could always try to obtain samples from Cornell Dubilier...
>> They are pretty motivated to provide them if you present them with a
>> well written usage plan indicating that you intend to incorporate them
>> into something that you are manufacturing and intend to purchase a lot
>> more in the future.
>> I'm not going to say how many they sent me, but they are plenty
>> generous
>> to potential customers.
>>
>>
>> "Failures are divided into two classes
>> those who thought and never did,
>> and those who did and never thought."
>> John Charles Salak
>>
>>
>> -----Original Message-----
>> From: Dave Leddon [mailto:dave at leddon.net]
>> Sent: Tuesday, September 15, 2009 1:25 PM
>> To: Tesla Coil Mailing List
>> Subject: Re: [TCML] Looking for pulse cap
>>
>> Phillip, Steve,
>>
>> Thanks for your insight. You both responded almost simultaneously with
>> the suggestion that I raise the value of my tank cap to 1 uf which has
>> several advantages, not the least of which is that it reduces the
>> capacitor count down to something almost manageable. Using the
>> 940C8W2K-F caps ($5.99 at rell.com) I could get by with 9 strings of 17
>> each and given that I already have 38 of these on hand my out of pocket
>> expense would only be, ka-ching $690. Still a bit more than I can
>> justify. So if anybody knows where I can score 1 uf at around 10,000
>> volts for less money, please let me know.
>>
>> Thanks,
>> Dave
>> Pleasanton, ca
>>
>> At 11:20 AM 9/15/2009, you wrote:
>>> Herr Zapp,
>>>
>>> The lower voltage ratings you may have seen were for 2 reasons: less
>>> current and secondly, they were over stressed.
>>>
>>> I used to run my MMC caps with peak AC voltages at the DC rating, and
>>> after enough time, one by one, the caps would fail. Testing shows
>>> that
>>
>>> the cap makers arent fibbing about the VAC ratings, stick with that
>>> and
>>
>>> it will last for a really long time.
>>>
>>> Dave,
>>>
>>> Id suggest going up higher than .5uF, perhaps to 1uF or so (i didnt
>>> specify this in our correspondence). Im running 1.25uF on an
>>> experimental setup at 1500A, but a lower frequency. While you get
>>> less
>>
>>> amp-turns in the primary, you do arrive at the higher peak current
>>> level faster, which translates to achieving a certain top voltage on
>>> the toroid faster, which is more efficient (in my data i saw a 20%
>>> efficiency improvement going from 8 cycles to 5 cycles of operation by
>>> increasing the tank cap value). You have current to spare with those
>>> big CM600s, so you should have no problem producing well over 10 foot
>>> sparks (id guess in the 14-16 foot range, secondary coil
>>> withstanding).
>>>
>>> Steve
>>>
>>> On Tue, Sep 15, 2009 at 10:48 AM, Quarkster <quarkster at att.net>
>>> wrote:
>>>
>>> > Matt -
>>> >
>>> > Eh??
>>> >
>>> > Clearly, my post contained no answers whatsoever, only questions to
>>> > try to gain a better understanding of Dave's rather unique capacitor
>> requirements.
>>> >
>>> > Most of the large DRSSTCs that I've seen get by using a cap with a
>>> > lower voltage rating, but they may not actually be attaining a
>>> > primary current of 2400A.
>>> >
>>> > Regards,
>>> > Herr Zapp
>>> > ----- Original Message ----- From: <mddeming at aol.com>
>>> > To: <tesla at pupman.com>
>>> > Sent: Monday, September 14, 2009 5:37 PM
>>> >
>>> > Subject: Re: [TCML] Looking for pulse cap
>>> >
>>> >
>>> >
>>> >> Hi Herr Zapp,
>>> >>
>>> >>
>>> >>
>>> >> Interesting questions, but how do they relate to answering the
>>> >> question Dave asked?
>>> >>
>>> >> Matt D.
>>> >>
>>> >>
>>> >>
>>> >> -----Original Message-----
>>> >> From: Quarkster <quarkster at att.net>
>>> >> To: Tesla Coil Mailing List <tesla at pupman.com>
>>> >> Sent: Mon, Sep 14, 2009 4:36 pm
>>> >> Subject: Re: [TCML] Looking for pulse cap
>>> >>
>>> >>
>>> >>
>>> >> Dave -?
>>> >> ?
>>> >> A few questions:?
>>> >> ?
>>> >> 1. How are you calculating the voltage requirements for the tank
>> cap??
>>> >> ?
>>> >> 2. How large a multiplier are you using to define the capacitor's
>>> >> voltage margin (safety factor)??
>>> >> ?
>>> >> 3. What is the manufacturer's voltage rating for the IGBTs you will
>>
>>> >> be using??
>>> >> ?
>>> >> 4. What is the calculated peak primary current??
>>> >> ?
>>> >> Regards,?
>>> >> Herr Zapp?
>>> >>
>>> >>
>>> >>
>>> >>
>>> >> ----- Original Message ----- From: "Dave Leddon" <dave at leddon.net>?
>>> >> To: "Tesla Coil Mailing List" <tesla at pupman.com>?
>>> >> Sent: Monday, September 14, 2009 11:19 AM?
>>> >> Subject: [TCML] Looking for pulse cap?
>>> >> ?
>>> >> Hi all,?
>>> >> ?
>>> >> ? I'm working on a fairly large DRSSTC and I find that an MMC
>>> >> adequate to
>>> >>
>>> >> ?the task may be out of my financial reach. If I were to push the
>>> >> igbt
>>> >>
>>> >> ?bridge to its limits I would require a cap rated at 20 kv at 0.5
>> mfd.
>>> >>
>>> >> ?This begins to sound like pole pig territory. If anyone has a cap
>>> >> like
>>> >>
>>> >> ?this that they would consider selling, or if they know of a
>>> >> resource that
>>> >>
>>> >> ?I can pursue, please let me know.?
>>> >> ?
>>> >> Thanks,?
>>> >> Dave?
>>> >> Pleasanton, Ca?
>>> >> ?
>>> >>
>>> >>> _______________________________________________?
>>> >>> Tesla mailing list?
>>> >>> Tesla at www.pupman.com?
>>> >>> http://www.pupman.com/mailman/listinfo/tesla ?
>>> >>>
>>> >> _______________________________________________?
>>> >> Tesla mailing list?
>>> >> Tesla at www.pupman.com?
>>> >> http://www.pupman.com/mailman/listinfo/tesla?
>>> >>
>>> >> _______________________________________________
>>> >> Tesla mailing list
>>> >> Tesla at www.pupman.com
>>> >> http://www.pupman.com/mailman/listinfo/tesla
>>> >>
>>> >
>>> > _______________________________________________
>>> >
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>>> >
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>>
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