From: Dhiya Mehdi (mehdi_at_tic.toshiba.com.au)
Date: 2001-12-03 02:19:40
To the group,
The following information may be relevant to IrDA issue.
An article on PC Infrared Transreceiver, was published in "Silicon Chip"
Magazine
of Australia December 2001 Issue.
The circuit uses the TFDS4500 Serial Infrared Transreceiver Module from
Vishay Telefunken.
This has onboard LED's (2 off), 5V, TXD, RXD terminals and requires external
resistors
(2 off) and capacitors (2 off) plus driver software (available from
Microsoft web site) to function.
The unit, mounted on a PCB, costs $27 Australian for a pair.
-----Original Message-----
From: Moritz von Buttlar [mailto:info_at_baltic-microsolutions.de]
Sent: Friday, 30 November 2001 12:37 PM
To: buildcheapeeg_at_yahoogroups.com
Subject: Re: [buildcheapeeg] Re: Optical data transmission
Hi Andreas,
> >But then you have to due all kinds of things like glueing the LED
> >to the fibre and so on which aren't perfect or professional :)
>
> Hehe, well, but its FUN! :-)
Maybe for us, but not for everyone out there, I think. We really have to
define what our goals are. For us, to have fun, or a design that can maybe
be later distributed to more people.
> It's possible to save on that part but theoretically you can injure
> somone badly by hooking up a pair of low-impedance electrodes and
> connecting a 9V battery directly to them. We'll have to make sure
> that even if the head-stage amplifiers get shorted to ground and
> power, the user is safe. I think the maximum allowed limit is 0.1mA
> current through the human body. Above that, things get uncomfortable
> fast. 1mA can be sensed and 5mA is painful.
Look at the schematics. There are some 10Meg resistors to prevent this. Of
course I'm thinking about battery operation for the future. That will get
rid of the noisy DC/DC converter that also isn't safe enough for medical
standards.
>
> >Also it's convenient and modern and interesting.
>
> Yes, it is. Are you thinking about a battery operated device here? I
> think I read in a data sheet that the LED in a IrDA transceiver can
> consume 100mA on average, and that is quite a lot.
IRMS6118 from Infineon
http://www.infineon.com/cgi/ecrm.dll/ecrm/scripts/prod_ov.jsp?oid=
13990&cat_oid=-8199
needs about 2.5 mA during transmission according to the data sheet. If we
use NiMH rechargeable batteries with 1500mAH capacity, we could run our EEG
for quite a long time without recharging. I'd like to use 4x1.2V batteries,
but I'm not sure about the OpAmps, how much voltage we need for them. For
voltage regulation I thought about a MAX603/4. Any other suggestions ?
Moritz
----------------------
Moritz von Buttlar
moritz_at_v...
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