From: Praveen Kumar (pkk7_at_y...)
Date: 2001-05-16 18:20:52
Hi everyone,
To sum up the recent discussion regarding use of sound
card, following problems were projected and their
solutions have also been suggested:
1. Linearized opto isolation - Solution proposed by
Anand John and recommended by Joerg Hansmann.
From: Anand John <deep_river79_at_y...>
To: <buildcheapeeg_at_yahoogroups.com>
Sent: Tuesday, May 01, 2001 2:35 PM
Subject: [buildcheapeeg] a different input circuit
2. Problem of response below 5 Hz. Solution proposed
by
Joerg Hansmann, that is, comparing the near DC signals
with two voltage reference levels and time
multiplexing them before feeding it to the sound card.
I wish someone could analyse (just to cross check)
it before it is accepted. It appears to be like
converting DC to AC by chopping. Whether all the
frequencies in the signal will be handled in the
similar fasion.
3. Problem of "digital smoothing technique applied
through the use of FFT, FIR" as projected by Dr Grant
Bright. If such a need arises, the solution is
readily available in LabView 5.1 of National
Instruments.
4. Though generally differential inputs are desired
in such cases, but sound card will take only single
ended inputs. Since the signals are being amplified
outside PC, singled ended inputs should be acceptable.
5. Cost advantage needs to be analysed. Joerge
Hansmann is familiar with Hardware of microcontroller
based system as well as the hardware required to be
used with the sound card. I think he will be the righ
person to comment upon it.
Praveen
India
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This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:29 BST