Gustavo Zubieta
New Member
Hello experts electronic gurus:
I am a 55 year old physician with passion for electronic knowledge. I have an old 8 channel Electroencephalogram Mingograf EEG Junior from Siemens-Elema, that previously used ink to register on paper. I want to digitize it to a PCL-711S PC Labcard. I have been able to connect Ekg and other equipment prefectly, before.
But now I decided to connect the EEG from the point of connection to the ink dispensers that injected ink to paper. The voltage reads around 3.5 VDC. But when I connect to the PCL-711, the voltage goes up to 7 VDC. So I used a voltage divider with two 1.5 Mohm resistors in series but when I again connected it, there is still no reading and eventually the main fuse of the EEG blows out.
1) Can someone please tell me what is wrong?
2) I figured I may have to use an optocoupler or optoisolator so I was thinking of using something like a 4N35. I would feed the voltage from the EEG to the led and then I would have variable voltage output at the phototransistor. Is this a good idea and a feasable one?
Thank you so much.
Gustavo
I am a 55 year old physician with passion for electronic knowledge. I have an old 8 channel Electroencephalogram Mingograf EEG Junior from Siemens-Elema, that previously used ink to register on paper. I want to digitize it to a PCL-711S PC Labcard. I have been able to connect Ekg and other equipment prefectly, before.
But now I decided to connect the EEG from the point of connection to the ink dispensers that injected ink to paper. The voltage reads around 3.5 VDC. But when I connect to the PCL-711, the voltage goes up to 7 VDC. So I used a voltage divider with two 1.5 Mohm resistors in series but when I again connected it, there is still no reading and eventually the main fuse of the EEG blows out.
1) Can someone please tell me what is wrong?
2) I figured I may have to use an optocoupler or optoisolator so I was thinking of using something like a 4N35. I would feed the voltage from the EEG to the led and then I would have variable voltage output at the phototransistor. Is this a good idea and a feasable one?
Thank you so much.
Gustavo