Excellent! Thanks! Do you happen to have a micrometer or calipers to measure
the diameter of the wire? If you do, please use sandpaper to take off the
lacquer coating to get an accurate measurement. Or you can stuff both wires
in an envelope and send it to me. :-) I have a micrometer and calipers.
Let me know if I should send you my address.
So, looking at the schemtics, T901 is switched on and off between the B+ and
B- rails, for about 53 volts minus the drop across Q905, so let's call it 52
volts. Then the secondary is listed as being -27.6, but it's connected on
one side to B-, or -26.4 volts. So, that's 1.2 volts across the secondary
and R926. I'm not sure why R926 is a 2W resistor, because the only current
would be to drive the base of a transistor, which should be in the mA range.
Then again, the size of the secondary wire in the picture is thicker than
that required to drive tens of mA.
Let's say it's 100 mA, then the drop across R926 is 0.22 volts.
So the primary is 26.4 volts versus the secondary at 1.2-.22 is 0.98,
or a ratio of 26.9:1. And 625 turns / 23 turns is a ratio of 27.2:1.
So your count of the turns ratio seems rather accurate.
In other words, I have faith in your counted turns. :-)
___
Ken
On 09/04/11 07:27, akswanson@ntelos.net wrote:
> Ok.. I pulled my transformer
>
> Primary : 625 turns (give or take some..lol Id say its within a percent or two)
> very fine wire
>
> Secondary: 23 turns
>
> pics for your enjoyment:
>
> http://www.flickr.com/photos/mcandrewsnd/sets/72157627466514605/
>
> > I heartily agree that whoever takes the time to investigate the properties
> > of the T901 transformer should post the info the the list, and hopefully
> > the list owner will save that info on the vectorlist website archives.
> >
> > If I finish rebuilding my living room/stero/TV setup this weekend, I'll
> > pull the working T901 from my spare WG high voltage board and try to
> > measure the turns ratio and the resistance of both coils. I'll post the
> > info here when I get it.
> >
> > ___
> > Ken
> >
> >
> > On 09/02/11 18:11, litterbox99@mchsi.com wrote:
> >> I can't imagine that someone hasn't done this
> >> before and documented it...
> >>
> >> It would be very usefull information.
> >> Kudos ! To someone who gives it a try.
> >>
> >> Todd
> >>
> >>
> >>
> >> ----- Original Message -----
> >>
> From: "Ken Sumrall"<k_lists@scrapheap.net>
> >> To: vectorlist@vectorlist.org
> >> Sent: Friday, September 2, 2011 6:53:26 PM GMT -06:00 Central America
> >> Subject: Re: VECTOR: K6100 T901
> >>
> >> If the old transformer is not too burned up, you can count turns as you
> >> unwind
> >> it. Sometimes only the insulation melts, leading to shorted bad
> >> transformers,
> >> but easy to count the turns as you unwind it.
> >>
> >> However, other times the wire itself melts/breaks, and then its harder
> >> to
> >> count as you unwind. If only one of the two coils is broken, you can
> >> use
> >> the turn count from one coil, and the measured ratio from a working
> >> transformer
> >> to figure out the turns count for the broken coil.
> >>
> >> Good luck if you choose to do it, and if you don't want to, you can send
> >> me
> >> your burned out transformer and I'll give it a try.
> >>
> >> ___
> >> Ken
> >>
> >>
> >> On 09/02/11 17:40, akswanson@ntelos.net wrote:
> >>> I have been contemplating rewinding it. I'll pull it apart and see how
> >>> bad. I
> >>> Love the 250ma fuse mod. Im thinking of some kind of fuse mod for this
> >>> G08 im
> >>> working on that keeps blowing output transistors (yes they are the
> >>> correct
> >>> devices, not the 3716s). Ugh.
> >>>
> >>> > I've thought about this some more, and it seems to me this would
> >>> not
> >>> > be that hard to rewind yourself. You can easily measure the turns
> >>> ratio
> >>> > of a working transformer with a signal generator set to the right
> >>> > frequency
> >>> > and a volt meter to read the output. Or just probe the input and
> >>> output
> >>> > terminals of the transformer in a working circuit, though the load
> >>> on the
> >>> > transformer could affect the readings.
> >>> >
> >>> > Then you could estimate the number of turns on the primary by
> >>> measuring
> >>> > the
> >>> > resistance of the wire and it's gauge, and using a chart that
> >>> lists the
> >>> > resistance/foot of the standard wire gauges.
> >>> >
> >>> > Winding transformers is not fun, but not hard to do. Just time
> >>> consuming.
> >>> > If there is enough demand, it might be worth while to get a batch
> >>> of them
> >>> > custom made.
> >>> >
> >>> > I know someone who sold a Scope Clock kit, and he had the special
> >>> > transformer
> >>> > he needed for his design custom made. I could ask him where he got
> >>> them
> >>> > made
> >>> > if there is enough interest to investigate this further.
> >>> >
> >>> > Is there a pent up demand for this transformer?
> >>> >
> >>> > ___
> >>> > Ken
> >>> >
> >>> >> --- k_lists@scrapheap.net wrote:
> >>> >>
> >>> >>
> >>>
> From: Ken Sumrall<k_lists@scrapheap.net>
> >>> >> To: vectorlist@vectorlist.org
> >>> >> Subject: Re: VECTOR: K6100 T901
> >>> >> Date: Sun, 28 Aug 2011 19:33:27 -0700
> >>> >>
> >>> >> I searched my local archives of the vector list, and found this
> >>> post
> >>> >> from July 8, 2007 from Hans O:
> >>> >>
> >>> >> > AH, now I remember. They're found in old B& W raster chassis.
> >>> >> > Track down an old 19V1001 or 1003 chassis. Should be a bunch
> >>> of
> >>> >> > dead ones out there.
> >>> >> >
> >>> >> > Hans O
> >>> >>
> >>> >> Good luck!
> >>> >>
> >>> >> ___
> >>> >> Ken
> >>> >>
> >>> >> akswanson@ntelos.net wrote:
> >>> >>
> >>> >>> lol..no worries.. I guessed maybe I had the wrong part ##. I
> >>> will
> >>> >>> DEFINATLEY check that out!!
> >>> >>>
> >>> >>>
> >>> >>>
> >>> >>> > Oops, I just realized you're not talking about the flyback,
> >>> but
> >>> >>> the
> >>> >>> > smaller transformer on the HV board.
> >>> >>> >
> >>> >>> > Sorry, I don't know where to get a new one of those. However,
> >>> I do
> >>> >>> > recommend you read the installation manual for the
> >>> replacement
> >>> >>> flyback
> >>> >>> > which you can find at the first link below. It includes
> >>> >>> instructions on
> >>> >>> > how to add 3 fuses to the HV circuit to protect components
> >>> >>> (including
> >>> >>> > T901) in the event of another failure like the one you have.
> >>> >>> >
> >>> >>> > ___
> >>> >>> > Ken
> >>> >>> >
> >>> >>> >
> >>> >>> > Ken Sumrall wrote:
> >>> >>> >
> >>> >>> >> You can get one here:
> >>> >>> >>
> >>> >>> >> http://www.cinelabs.com/wg6100/
> >>> >>> >>
> >>> >>> >> which has link to here:
> >>> >>> >>
> >>> >>> >> http://arcadeshop.com/wgxy-fb/wgxy-fb.htm
> >>> >>> >>
> >>> >>> >> $79, and comes with extra protection components and a new
> >>> focus
> >>> >>> >> assembly.
> >>> >>> >>
> >>> >>> >> Note, I've never ordered or used one of these flybacks, I
> >>> just
> >>> >> remmeber
> >>> >>> >> seeing it recently while searching for other parts to bring
> >>> a
> >>> >>> 6100
> >>> >> back
> >>> >>> >> to life.
> >>> >>> >>
> >>> >>> >> ___
> >>> >>> >> Ken
> >>> >>> >>
> >>> >>> >>
> >>> >>> >> akswanson@ntelos.net wrote:
> >>> >>> >>
> >>> >>> >>> I had suspected the triple nickel (555), and indeed it was
> >>> >>> fried.
> >>> >>> >>> It also took out Q905, AND T901.. I verified this by trying
> >>> T901
> >>> >>> in a
> >>> >>> >>> known good HV unit. I got smoke, and another blown Q905..
> >>> So if
> >>> >>> >>> anybody knows where I can get a replacement T901 thatd be
> >>> swell!
> >>> >>> >>>
> >>> >>> >>>
> >>> >>> >>>
> >>> >>> >>> > I'm not saying that you don't have a bad T901, but can
> >>> you
> >>> >>> verify
> >>> >>> >>> that
> >>> >>> >>> > IC901 (555 timer as a simple oscillator) is running. A
> >>> scope
> >>> >>> would
> >>> >>> >>> show a
> >>> >>> >>> > nice square wave coming out at pin 3. If it is stuck in
> >>> the
> >>> >>> high
> >>> >>> >>> state,
> >>> >>> >>> > it would keep Q904 and Q905 turned on constantly and
> >>> that
> >>> >>> would
> >>> >>> >>> certainly
> >>> >>> >>> > cause your problem. Of course in this state, there would
> >>> be
> >>> >>> no HV
> >>> >>> >>> output
> >>> >>> >>> > at all. Check ZD900 for 13V across it. ZD900 is the
> >>> voltage
> >>> >>> >>> regulator
> >>> >>> >>> > for the 555 chip. If the zener is partially shorted and
> >>> there
> >>> >>> isn't
> >>> >>> >>> > enough voltage across the 555 chip, then the 555 chip
> >>> output
> >>> >>> might
> >>> >>> >>> be
> >>> >>> >>> > stuck even if there's nothing wrong with it. If the
> >>> zener is
> >>> >>> >>> > open-circuit, the 555 chip will likely have blown.
> >>> >>> >>> >
> >>> >>> >>> > You should remove R917 and leave it out until you can
> >>> verify
> >>> >>> that
> >>> >>> >>> IC901 is
> >>> >>> >>> > running okay and that the transistors Q904/905 are both
> >>> >>> switching.
> >>> >>> >>> To
> >>> >>> >>> > functionally test Q905, you can add a temporary 10k (to
> >>> 47k)
> >>> >>> >>> resistor
> >>> >>> >>> > (1/2W to 1W) from +Vsupply (+28V) to Q905 collector. If
> >>> scope
> >>> >>> shows
> >>> >>> >>> a
> >>> >>> >>> > good square wave, remove the temporary resistor and
> >>> return
> >>> >>> your
> >>> >>> >>> focus to
> >>> >>> >>> > T901.
> >>> >>> >>> > If you do not have a scope but you have a voltmeter,
> >>> connect
> >>> >>> your
> >>> >>> >>> meter
> >>> >>> >>> > (-) to ZD900 anode or IC901 pin 1. Use the meter(+) to
> >>> >>> measure
> >>> >>> >>> voltage at
> >>> >>> >>> > ZD900 cathode and IC901 pin 8. Both should be about 13V.
> >>> >>> Measure
> >>> >>> >>> IC901
> >>> >>> >>> > pin 3. If it is running, it should be around 6.5V
> >>> plus/minus
> >>> >>> around
> >>> >>> >>> 0.5V
> >>> >>> >>> > roughly. The point here is that pin 3 should be
> >>> outputting a
> >>> >>> square
> >>> >>> >>> wave
> >>> >>> >>> > having roughly a 50% duty cycle so the voltmeter should
> >>> show
> >>> >>> >>> approximately
> >>> >>> >>> > one half the chip supply voltage.
> >>> >>> >>> >
> >>> >>> >>> >
> >>> >>> >>> > William Boucher
> >>> >>> >>> > http://www.biltronix.com
> >>> >>> >>> > ----- Original Message -----
> >>> >>> >>> >
> >>> >>> >>>
> >>> >>>
> >>>
> From: akswanson@ntelos.net
> >>> >>> >>> > To: vectorlist@vectorlist.org
> >>> >>> >>> > Sent: Sunday, August 28, 2011 9:20 AM
> >>> >>> >>> > Subject: VECTOR: K6100 T901
> >>> >>> >>> >
> >>> >>> >>> >
> >>> >>> >>> > One of my 6100s had a fire on the HV board, took out
> >>> R917 and
> >>> >>> Q905.
> >>> >>> >>> I
> >>> >>> >>> > replaced those, and got smoke again.. Comparing the
> >>> >>> resistance of
> >>> >>> >>> the
> >>> >>> >>> > primary of T901 to a known working T901 I get 9.5 Ohms
> >>> on the
> >>> >>> >>> suspected
> >>> >>> >>> > bad one and 17 ohms on the known good one. I get the
> >>> feeling
> >>> >>> I
> >>> >>> >>> melted
> >>> >>> >>> > the varnish on the wiring and shorted them together..
> >>> Does
> >>> >>> anyone
> >>> >>> >>> know
> >>> >>> >>> > where (or have) and extra T901? Also, Is there a
> >>> secondary
> >>> >>> cause,
> >>> >>> >>> such
> >>> >>> >>> > as a flyback failure that would cause this kind of
> >>> failure? I
> >>> >>> dont
> >>> >>> >>> > want to blow the dang thing again..
> >>> >>> >>> >
> >>> >>> >>> >
> >>> >>> >>> >
> >>> >>> >>> > Andrew
> >>> >>> >>> >
> >>> >>> >>>
> >>> >>> >>
> >>> >>>
> >>> >> ---------------------------------------------------------------------------
> >>> >>> >> ** Unsubscribe, subscribe, or view the archives at
> >>> >>> >> http://www.vectorlist.org
> >>> >>> >> ** Please direct other questions, comments, or problems to
> >>> >>> >> chris@westnet.com
> >>> >>> >>
> >>> >>> >>
> >>> >>> >
> >>> >>>
> >>> >> ---------------------------------------------------------------------------
> >>> >>> > ** Unsubscribe, subscribe, or view the archives at
> >>> >>> > http://www.vectorlist.org
> >>> >>> > ** Please direct other questions, comments, or problems to
> >>> >>> > chris@westnet.com
> >>> >>> >
> >>> >>>
> >>> >> ---------------------------------------------------------------------------
> >>> >> ** Unsubscribe, subscribe, or view the archives at
> >>> >> http://www.vectorlist.org
> >>> >> ** Please direct other questions, comments, or problems to
> >>> >> chris@westnet.com
> >>> >>
> >>> >>
> >>> >> ---------------------------------------------------------------------------
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> >>> >> http://www.vectorlist.org
> >>> >> ** Please direct other questions, comments, or problems to
> >>> >> chris@westnet.com
> >>> >>
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> >>> >> ** Please direct other questions, comments, or problems to
> >>> >> chris@westnet.com
> >>> >>
> >>> >>
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> >>> > ** Please direct other questions, comments, or problems to
> >>> > chris@westnet.com
> >>> >
> >>>
> >> ---------------------------------------------------------------------------
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> >> http://www.vectorlist.org
> >> ** Please direct other questions, comments, or problems to
> >> chris@westnet.com
> >> ---------------------------------------------------------------------------
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> >> http://www.vectorlist.org
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> >> chris@westnet.com
> >>
> >>
> > ---------------------------------------------------------------------------
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> > chris@westnet.com
> >
>
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Received on Tue Sep 6 21:38:58 2011
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