Re: TI-H: EL Backlight installed!
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Re: TI-H: EL Backlight installed!
From: Grant Stockly <gussie@alaska.net>
>Get a transistor that connects to the power line of the LCD. If the
LCD
>gets power (you put a 'High' signal in) then the transistor pulls its
line
>'high'. That way when the LCD is on, so is the back light...
simple? :)
>
>>I'd like to know how to use a transistor to turn it off when the
calc is
>>turned off!
Thats what I was planning on. The screen is a very small amount
dimmer,
due to the voltage drop of the collector-emitter junction of the
transistor,
but its really not all that noticable.
I played with it last night, but I wasn't sure which lead was the LCD
turn on lead (or if there was one). The calculator appears to be
powered all the time (pulling about 8uA), just with the LCD off. The
power leads (fat traces on the left side of the cable connecting the
two boards together) are active all the time. I didn't have a scope
handy, and the multimeter was having trouble with the AC component
of the badly filtered DC supply I was using. It was late so I gave
it up until later.
Anyone know how the LCD is signaled to turn it on?
DK
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