Re: 19K6400

On Thu, 22 Jan 1998 16:25:46 -0800, Clay Cowgill <ClayC@diamondmm.com> wrote:

>> When you say "modyfying", how drastic were you thinking? Since the
>> operating voltage is different, you would need a new power isolation
>> transformer. Plus the HV PCB is quite different since it only runs on
>> positive.
>>
>I was thinking:
>
>1) new transformer for 40-0-40 power (or whatever is needed)
>
>2) double up transistors/Deflection board modifications + the LV2000
>(maybe with another little regulator or zener to raise the adj leg to
>allow regulation over the higher voltage)
>
>3) HV supply. Got two ideas here. Plan "A"-- rework it for +48V
>operation (Which didn't actually sound too bad from Dave's original
>write-up). Plan "B" Just make a split voltage regulated supply and run
>it off the "original" voltages. I haven't tested this theory yet, but
>I'm thinking that since I don't need deflection current coming off this
>guy I might get away with just some heat-sinked TO-220 regulators.
>(~1.5amp) Anybody know what a HV cage draws?

From what Atari has done, it looks like the 1.5 amp regulators work, almost.

The Amplifone monitors used this design, yet most have been retro fitted with
50ohm resistor across the in/out pins. From playing with these things with a
scope it looks like things like the Star Wars star exploding need more current
than the regulator can supply. When these kind of currents are needed part of
the current is passed through the 50ohm resistor (I'm sure regulation at this
point is gone).
>
>> I am not convinced that mearly doubling up the deflection transistors
>> (which was done on the 6400) will improve the monitor. However,
>> increasing
>> the supply voltage and thus the speed of the monitor could be
>> interesting.

If you increase the supply voltage you will have to double up the transistors (I
think this is what you meant, I just wanted to be clear.)

-Zonn

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Received on Thu Jan 22 16:44:26 1998