Re: [Openeeg-list] Mine finally works

[Ian V. <vi...@ig...>]

At 07:56 AM 4/29/03 +0200, you wrote:
>Well, the same happened to me - I killed two INA114AP already - it seems
>they are extremly
>sensitive, because second time I was really very careful.
>The symptoms are that one channel is working correctly but the other is
>unstable
>(sometimes when you touch it, sometimes without) and it can influence the
>other channel.
>It could be maybe written into Troubleshooting guide.


Same thing..I have two channels that are different, but I didnt know which
one was the right one. I actually built a test circuit for the INA114's and
they both seemed to work fine, but in the Olimex board, channel two is
still very unstable, but so is my DRL, if I look at it with a scope. You
dont seem to be able to adjust it to 15mv, it goes +5 & -5, but it still
cancels the hum OK. I think I still have a gremlin in the works. Im glad im
not the only one to experience this.

It has a kind of unpredictable character to it, sometimes its there,
sometimes its not.

In the end I made a wee sine wave oscillator, based on a XR2206 Function
Generator and fed that into the input terminals at 14Hz about 100uv. That
showed the problem up as a distortion that you could actually see in the
ElectricGuru trace. One Channel was fine, the other distorted. If I changed
the chips over, the distortion shifted. 

It wouldnt suprise me if there are some other ModEEG units around with the
same problem.

Ian