Re: yoke resonant frequency

Al Kossow wrote:
>
> re: damping factor
>
> the image you sent was at too low a resolution to make much out, but
> a few things i've noticed is:
>
> 1) there is no output protection, or sense resistor for feedback
> 2) there is no damping at all across the yoke (it will have the
> same gate-drain breakdown problems that the present design has
> 3) the voltage rating of the MOSFETS will have to be the sum of
> the supply rails.
>
> for a class AB driver, my cube neighbor suggested the LT1166 Power
> Output Stage Automatic Bias System.

The drawing was a simplistic way of using mosfets. I just sketched the
output configuration. There is an arrow pointing to the diff amp for
the feedback. I just did not draw the rest of the circuit at all.
The only problem I have with a class AB is zero cross ref problems.
Even if there is a lot of feedback, you will probably still have
problems.
As you approach zero on the input, you will have some distortion.
I guess I am looking at this like an amplifier <deflection circuit> and
a
speaker <yoke>. Hence, if using a class AB the output stage is held at
the
threshold of the on state. If a small signal is applied, it will show
some
distortion. As you increase the volume or signal, the distortion is less
appearant because you are biasing the output stage to the on state more
but, there are also transient noises from the transistors turning on and
off.
Received on Tue Sep 2 18:55:19 1997