Re: yoke resonant frequency

At 01:50 PM 9/3/97 -0500, you wrote:
>> I've been lurking on this subject for a while and have an armchair
>> engineering question. Has anyone hooked up a spectrum analyzer to see
>> what the spectral content is of the vector signals? With all this talk
>> about hooking up audio amps makes me wonder if this will filter off some
>> of the high end of the signal.
>
>Of course it should be measured at the output of the driver because the
>yoke itself will cut out some high frequency stuff. Which brings me to
>another question:
> Aren't deflection coils current controled? i.e. isn't the deflection
>proportional to the current and NOT the voltage across the coils? I know
>this is a really basic question, but I've never dug into the schematics
>really good and they look like an audio amp at first glance. BTW, I've
>often wondered if speakers should be current driven for similar reasons.

They are current controlled, if they were simply resistive it wouldn't make
any difference whether you looked for current or voltage. They're inductive
and the amount of deflection depends on the amount of current flow, not the
voltage across the yoke.

And yes I've also wondered if speakers should be current driven for similar
reasons! I guess the biggest problem with that is that the current to
voltage resistor used in the normal current controlled design could really
mess up the damping factor and your low end could get pretty muddy.

-Zonn
Received on Wed Sep 3 12:12:53 1997