Re: K6100 T901

akswanson sent me pieces of the wire from the primary and secondary coils of
T901. Using some very fine sandpaper, I sanded off the insulation, and measured
the wire diameter with some nice Mitutoyo calipers.

The primary wire measured .0065 inch, which according to wikipedia:

   http://en.wikipedia.org/wiki/American_wire_gauge

is AWG 34.

The secondary wire measured at .025 inch, which is AWG 22.

So, putting it all together, the specs for T901 are:

   Primary coil: 625 turns of AWG 34 wire
   Secondary coil: 23 turns of AWG 22 wire

Anyone want to try and wind their own? akswanson has an empty bobbin and
core. :-)

___
Ken

On 09/06/11 18:38, Ken Sumrall wrote:
> 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
>> >>> >>> >>> >
>> >>> >>> >>>
>> >>> >>> >>
>> >>> >>>
>> >>> >>
>> ---------------------------------------------------------------------------
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>> >>> >>> >> chris@westnet.com
>> >>> >>> >>
>> >>> >>> >>
>> >>> >>> >
>> >>> >>>
>> >>> >>
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>> >>> >>> > chris@westnet.com
>> >>> >>> >
>> >>> >>>
>> >>> >>
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>> >>> >>
>> >>> >>
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Received on Fri Sep 16 16:48:39 2011