Olimex Support Forum

Others => Biofeedback - EEG, ECG, EKG => Topic started by: Konstantin on February 19, 2013, 01:27:29 pm

Title: Opto-coupter and electric circuit of EEG-SMT
Post by: Konstantin on February 19, 2013, 01:27:29 pm
Hello!

Can anyone explain me please? There written about opto-coupter: http://openeeg.sourceforge.net/doc/modeeg/modeeg_design.html (http://openeeg.sourceforge.net/doc/modeeg/modeeg_design.html)
Where Is it on electric circuit of EEG-SMT?

Best regards.
Title: Re: Opto-coupter and electric circuit of EEG-SMT
Post by: LubOlimex on February 19, 2013, 01:56:19 pm
Hello Konstantin,

There is no such an opto-coupler in latest revisions of EEG-SMT. Instead of such we use ISO7221XD (U3) - dual digital isolator.

Best regards,
Lub/OLIMEX
Title: Re: Opto-coupter and electric circuit of EEG-SMT
Post by: Konstantin on February 19, 2013, 05:02:58 pm
Thank you for the answer!
Title: Re: Opto-coupter and electric circuit of EEG-SMT
Post by: Konstantin on February 20, 2013, 11:09:17 am
Another question:

It is about EEG-SMT from here: https://www.olimex.com/Products/EEG/OpenEEG/EEG-SMT/ (https://www.olimex.com/Products/EEG/OpenEEG/EEG-SMT/)
CH1+ and CH1- are for the electrodes of one amplifier channel from here: http://openeeg.sourceforge.net/doc/modeeg/modeeg_design.html (http://openeeg.sourceforge.net/doc/modeeg/modeeg_design.html)
("Simplified block diagram of the ModularEEG amplifier"). CH1+ and CH1- are for observing of the voltage difference between two points on the scalp.
Am I right?

Title: Re: Opto-coupter and electric circuit of EEG-SMT
Post by: LubOlimex on February 21, 2013, 01:06:51 pm
Yes. That is why it is good idea to place  both electrodes of one channel symmetrically across the skull.

Best regards,
Lub/OLIMEX
Title: Re: Opto-coupter and electric circuit of EEG-SMT
Post by: Konstantin on February 26, 2013, 03:41:18 pm
Great! Thank you!