Re: TI-H: LED Backlight

To: ti-hardware@lists.ticalc.org
Subject: Re: TI-H: LED Backlight
From: Grant Stockly <gussie@alaska.net>
Date: Thu, 28 Jan 1999 17:33:27 -0900
Delivered-To: ti-hardware-outgoing@towerguard.unix.edu.sollentuna.se
Delivered-To: ti-hardware@lists.ticalc.org
In-Reply-To: <014901be4b24$b21fffe0$c9648ed1@vizzini.rdtech.>
Reply-To: ti-hardware@lists.ticalc.org


>From: Grant Stockly <gussie@alaska.net>
>>A PN222 will amp a 10ma signal to a minimum of 75ma and a max of 300.  They
>>leak .1ma.
>
>
>Input signal for the switch is approximately 0.05mA, which is one reason I
>suggest
>a darlington (which typically has a gain of 4,000-75,000 for those of you
>who are
>not familiar with them).
>
>There are lots of ways to improve and/or fix the circuit as it stands,
>however, I have
>a totally new design that I will be testing as soon as I can locate parts.

I use the 2222s since you can get a thousand for $12.  Thats a much bigger
gain.

Grant

References:

Re: TI-H: LED Backlight

From: "David Knaack" <dknaack@geocities.com>