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RE: why 4 Ohms in PARALLEL with trigger coil primary?



Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi Ted,

At 06:49 AM 10/18/2001 -0500, you wrote:
>More to add:
>Last night I checked my notes with respect to those two paralleled 8 ohm, 20
>W, resistors.
>After my last exchange with Terry while putting the tgap togther, I moved
>them from the position shown on the schematic in my paper.
>Their final (working) position is in series with the HOT (Black) lead after
>the Lutron and before the HEI coil. I will modify the schematic and send
>another copy to Terry so he has the most accurate info.

OK,  That explains why they aren't on fire :-))  So they are probably in
series which matches my memory of our discussion back then.

>
>No matter what I tried, when they are across the 120 input, they are
>dangerous unless you want a toasted English Muffin.

They should burn right up but the dimmer may only limit them to getting
white hot :-))

>
>Are they performing a service in this series position? I do not know.
>However, even if they are now just decoration, the tgap works so I don't
>care.

Hmmmm.  There is a chance they are just not doing too much.  Or maybe they
are doing something wonderful...  I am not at all sure.  Maybe Marc knows.
If it works, it works.  But maybe we need to figure out a few of the finer
details still :-))

>
>Terry, Marc, others...if you evaluate the reason for the resistors and can
>add to the knowledge base here, I am sure interested in the "why."

My big resistors were to make the coil look less like a big
capacitor/inductor and more like a resistor so that the dimmer would see
more of the kind of load it was meant for.  However, you dimmer is designed
for reactive loads (fan control) so things are different.  I don't know to
much more at this moment regarding the fan control operation and what it
all means...

Cheers,

	Terry


>
>Safety First
>
>Ted
>
>-----Original Message-----
>From: Tesla list [mailto:tesla-at-pupman-dot-com]
>Sent: Wednesday, October 17, 2001 10:13 PM
>To: tesla-at-pupman-dot-com
>Subject: RE: why 4 Ohms in PARALLEL with trigger coil primary?
>
>
>Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
>Hi All,
>
>We have been having some (sort of off list) discussion about the 4 ohms of
>resistance across the HEI coil's primary in Ted's plans...  It seems like
>these resistors would burn right up.  We are a little unsure of what is
>going on but I thought you all should know about this mystery too incase
>you try it.  If "you" figure it out, let "us" know :-))
>
>---------------------
>Hmmmmm,
>
>If you but 4 ohms directly across the ac line, it will dissipate 3600
>watts...  The dimmer would limit that to maybe 1000 watts...  Something
>strange must be going on there.  However, if it works, it works.  But I
>think there is a good chance they are blown open which would probably have
>little effect.  I would leave it for now and maybe when you can play with
>you coil at length, check into it more.  Next time you see the coil, you
>may want to double check to see that they really are across the neutral and
>hot wires out of the dimmer and not in series.  Check the resistance if you
>can.  I bet it is higher than 4 ohms :-))
>
>Cheers,
>
>	Terry
>
>
>At 12:40 PM 10/17/2001 -0500, Ted Rosenberg wrote:
>>Hi Terry. Hey, if I can type at 6AM (I work from 7 to 4  :)....
>>No matter.
>>
>>The resistance was based on Marc's picking different low values on his
>first
>>iteration of connections...remember? The 10µF motor run cap and the 10 ohms
>>etc. It was about the same time you were using the 250W huge reistors? (I
>>have two...any ideas? They do not make good wind chimes!)
>>
>>Then Marc said that 4 ohms would be OK but he was not terribly clear as to
>>exactly where!!
>>Well, I didn't have 4 ohms. So two 8's in parallel gave me the 4 <at 40
>>watts>. Then I put them in series in the line and I almost burned up the
>>coil from the heat. That's when I got hold of you and you suggested across
>>the HEI. And that worked.
>>
>>Does that clarify? Or should I try and followup with Marc?
>>
>>-----Original Message-----
>>From: Terry Fritz [mailto:twftesla-at-qwest-dot-net]
>>Sent: Wednesday, October 17, 2001 12:33 PM
>>To: Ted Rosenberg; 'Scott.L.Hanson-at-seagate-dot-com'
>>Subject: RE: why 4 Ohms in PARALLEL with trigger coil primary?
>>
>>
>>Hi Ted and Scott,
>>
>>I forwarded this to the Tesla list by accident.  Sorry bout that...  You
>>may want to write me at:
>>
>>terrellf-at-qwest-dot-net
>>
>>So the sleepy Terry can't just forward all the morning mail on without
>>checking who it is addressed to...
>>
>>I did not understand why the resistors would be in parallel either :o)  I
>>thought they should be in series.  I figured, well, I guess it works for
>>Ted ok...  You may want to check them with an ohmmeter.  I wonder if they
>>blew open in the first second and they are just open now.  If they were
>>open, you may not notice (maybe they don't matter...).
>>
>>Cheers,
>>
>>	Terry
>>
>>At 07:02 AM 10/17/2001 -0500, Ted Rosenberg wrote:
>>>Hi Scott and thanks for the compliment.
>>>I have some answers for you but please understand, as I said in the paper,
>>I
>>>was the technician. Marc and Terry Fritz deserve the "why" rewards!
>>>
>>>I originally had the 4 ohms in-line. the resistors got SO hot that they
>>>would have burned the wood etc etc. I desparately e-mailed Terry as Marc
>>was
>>>unavailable. After some discussion, Terry suggested the new position
>>>and...it works. I really can't give you a better reason. Sorry. Perhaps
>you
>>>might ask Terry about that. Who knows, I might learn something  :))
>>>
>>>I do not own an oscope although I can borrow one.
>>>I had to get this coil into the Hangman's House of Horrors and I was
>>running
>>>out of time. So all seriosu tweaking, checking with scope, adding welders
>>>glass etc, will have to wait until the coil returns home after Oct 31.
>>>
>snip...
>