TI-H: Help! Constat voltage in link cable!

To: ti-hardware@lists.ticalc.org
Subject: TI-H: Help! Constat voltage in link cable!
From: ffolkes Sedneff <ffolkes@ffolkes.com>
Date: Thu, 29 Oct 1998 21:43:26 -0500
Delivered-To: ti-hardware-outgoing@towerguard.unix.edu.sollentuna.se
References: <3.0.6.32.19981029200423.007ba610@mail.cybrzn.com>
Reply-To: ti-hardware@lists.ticalc.org



Hello-

I was working on an idea, and as a kind of "test" I designed a flip/flop circuit
using a bunch of ICs that would light an LED upon the calc sending a "surge" of
voltage through the link port.....AKA send something causing voltage to go
through the red or white wire, but there are two problems.......
1. There is ALWAYS something coming out of the calc's (TI92+) link port cable.
Why does it never stop? When I try to send, it goes up by about 2 volts, and
thats it.....what the $%&^%&^ is happening???? I hadn't anticipated this!
2. I can't find the correct type of circuit, the one I have is a latching C-MOS
type, which requires a break in continuity to turn the LED on and off. Does
anyone know of a good one that would turn it on and off by sending voltage to it?
Kinda like a latching relay?
This would eventually pan out to me a digital multimeter that would be interfaced
with my TI-92. If anyone thinks that it would be better to use another calc, like
a TI-89, or 82 or 85 or 86, or anything, I would gladly buy a calc of that type
and play around with it, as long as it would be better than my TI92.
Thanks


ffolkes

Follow-Ups:

Re: TI-H: Help! Constat voltage in link cable!

From: kaus <kaus@cybrzn.com>

References:

Re: TI-H: Calc LockUp. Saga Part II

From: kaus <kaus@cybrzn.com>