Re: G08's and inductive kick

At 03:20 PM 8/29/97 -0700, you wrote:
>
>Talking to the guy in the next cube, the NPN-NPN design of the G08
>will have a problem with inductive kick in one direction that the
>PNP/NPN designs won't have.

Since everything going to the yoke is symmetrical, it seems like any kind of
kick you get in one direction you can show that by reversing all currents
involved you see a kick in the other direction. It does allow for the use of
high voltage deflection transistors that are not manufactured in a PNP form.

>He also thought that the relatively low voltage ratings of the
>3716/19 might make this a problem for the WG as well.
>
>The other thing he was wondering if you only drove the output
>transistors from the unregulated supply or the diff amp and
>pre driver as well. If the negative rail isn't well regulated
>in the diff amp, you are going to inject a whole bunch of noise
>through the current source.

That's a really good point I had not taken into account! This is definitely
something to try! Regulate the error amp, and not the drivers. From memory
I believe there is a resistor between the voltage supplies and the error
amps that looks as though it's part a simple R/C that helps regulate the
error amps power. I'll bet removing those resistors and replacing the
voltage with regulated voltages could possibly give a nice solid display
without having to have, high power, low voltage, regulation.
Received on Fri Aug 29 16:13:22 1997