TI-H: TI-86 Slowdown with EL backlight
[Prev][Next][Index][Thread]
TI-H: TI-86 Slowdown with EL backlight
Alright, I installed a backlight in an 86 for the first time,
and I've run into the slowdown problem. The calc works fine
if the backlight is off, but as soon as I turn on the inverter
the calc drops to a much slower speed. This is happening with
new or old batteries, and does not appear to be effected by a
series resistor, which seemed to fix the problem in other 86s.
I have tried several series resistances in the inverter supply
line, including 10, 22, 32 and 47 ohms. The slowdown is not
effected at 32 ohms, and at 47 ohms the inverter does not come
on.
I rigged up a seperate battery supply and powered the inverter
from that, with the calc running from its own battery supply
and every thing worked as normal. Linking the grounds of the
two supplies immediatly slowed the calc.
The only thing I can think of as a cause is noise that the
inverter is causing in the power supply. Bybass caps of
100uf, 50pf and 2pf across the battery supply had no effect
on the problem.
I will attempt to get a 'scope in here so I can check things
in more detail sometime this week, but in the meantime, can
anyone suggest some more diagnostic procedures, or suggest
some possable solutions?
Thanks
DK
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
Follow-Ups: