Re: New vector monitor design.

At 08:12 PM 5/27/97 EDT, you wrote:
>Clay sez...
>
>>I have an old B/W 12" monitor that came out of a bootleg Asteroids
>>Cocktail. The interesting thing about it is that there are *very* few
>>parts on the board. What the designers did, was use a pair of those
>>STK0080 (I think that's it, it might have been the STK0050) audio amps
>for
>>the deflection drive. (Think about 2"x3" hybrid package thing, they're
>in
>>NTE/ECG/etc if you want to look them up.)
>
>FWIW Modules are available from consumer electronics repair houses *much*
>cheaper than NTE/ECG. Try Dalbani. The STK0050 and STK0080 usually
>run about $10-$15 each.
>
>I was mentally dinking around with Zonn's proposal and I remembered I
>have
>a 100W audio amp with lots of input/output protection. I might just try
>driving
>the modified yoke with it and see if we get the required deflection. If
>that works,
>I might try using some cheap audio amps that HSC is selling. They were
>made for home theatre stuff and might have sufficient drive for this.
>
>>The STK0080 are these big SIP package integrated audio amps like you'd
>find
>>in a Fisher or low-end Sony consumer Receiver/Amp. Built in heat sink,
>
>Actually, they don't have a built-in sink. Just a metal pad that you
>mount *on*
>a heat sink. These aren't used too much in the stuff I fix lately. They
>went
>back to discrete output devices. Cheaper I suppose.
>
>>overcurrent protection, over temp protection, etc.
>
>Are you sure about this one? Do you have data sheets?
>
>Lastly, regarding Zonn's proposal...I always thought the yoke was an
>integral
>part of the HVT design of a raster display. If we start changing the yoke
>Z, won't
>that mess things up? I remember John (of John's Jukes) using a loose yoke
>to keep the raster chassis happy in his vector HV hack.

Good point!

If the yoke is part of the Flyback design (and yes it is, the term "Flyback"
refers to the trace being deflected past the zero point by sending the trace
off in one direction and then letting it "Flyback" to the extreme negative
position. It's a tuned circuit similar to a type "C" type amplifier, if you
look in an amplifier theory book.)

And I believe Al is right in that as long as this regulated tuned circuit
exists, it's easy (for the flyback manufactor) to add an extra windings in
the flyback transformer to create the High Voltage!

That sure is a snag in the HV generation!

That means either I find a TV that will allow the use of a standard X/Y yoke
(and let the raster yoke dangle) or I have to come up with a way of
generating HV on my own. I would think one way of doing it would be to
drive the TV's flyback's primary with a standard 15khz oscillator of my own,
using the anode voltage generated as the feedback used to regulate the HV,
much like WG monitors do.

Damn, this conversion is getting really complicated!

BTW: I'm not looking for a universal low cost way of building a reliable X/Y
monitor, I'm looking for a 33" 4-player eliminator playing field! These
could be mutually exclusive goals.

-Zonn
Received on Tue May 27 19:06:45 1997