RE: AW: [Lcd4linux-devel] USB based hd44780 units ...

[Luis.F.Correia <Lui...@se...>]

Hi there,=20

> -----Original Message-----
> From: Michael Reinelt [mailto:re...@eu...]=20
> Sent: Thursday, January 26, 2006 10:02 AM
> To: lcd...@li...
> Subject: Re: AW: [Lcd4linux-devel] USB based hd44780 units ...
>=20
> Hi there,
>=20
> >>I've just an other question. Does your layout support a negative=20
> >>contrast voltage? I've a display which needs a negative contrast =20
> >>voltage...
>=20
> Really? A HD44780 Display with *negative* contrast voltage?=20
> Never seen this...
>=20
> anyway, there are very small DC/DC converters which can=20
> produce -5V (or even -12V) out of +5V.
>=20
> Look for "RO-0505S", Conrad sells them for about 8=E2=82=AC

there is a much more cheaper source for those DC-DC converters,
old ethernet cards with the BNC connector, it is a big black block,
shown vertically with the letters YLC, in this link:

http://blackbox.minidns.net/Bilder/Verkauf/isa_ne2000.jpg

In this case it is a 12V to 9V converter, which can be used to=20
provide negative voltage, by properly connecting it.
There are some datasheets available for those DC-DC converters,
just search for the model you got.

Hope this helps a bit ;)


Luis Correia  =20
Bering uClibc Team Member

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