Recent content by bill.connelly

Thanks Skeptic I've added in the isolators where I think you wanted them, is this correct?

No, no... no furry creatures... cancer cells removed from a human decades ago... This guy has posted something similar http://www.nbb.cornell.edu/neurobio/land/PROJECTS/SIU/index.html Except it seems very complicated. I can't figure it out enough to simplyfy it (I can't even figure out what...

Yeah, I though this would blow your average OP-amp... Double dang about the optocoupler... I thought it seemed to good to be true... thanks for your thoughts anyway. Okay, say I was fixed the resistor lay out, and reduced the power voltage to 50V (making the resistors 1kOhm and 9kOhm). Is there...

Hi, I've had a few thoughts, how does this look?

Hi, I'm trying to build what a biologist would call a "stimulus isolator". That is, I have a voltage follower connected to a system that I want to zap with 0-100V, so that the voltage follower doesn't see the voltage (much). I have an A/D board that can put out 0 to 5 Volts. I want this...

Is that too hard to calculate the difference equation for? Is it likely there is another forum that someone might be able to do it?

Ah, excellent. That is amazing! How complicated does it get if between events, instead of the process recoverying with a single exponential, it recovery with a bi-exponential i.e. the equation for the second event would be Y=Y1*D + (1-Y1*D)*PercentFast*(1-exp(-KFast*i)) +...

Interesting... the seems to match very closely apart from the fact that the initial value is not 1, i.e. when n = 1

Okay... and how do your constants of A and B relate to my constants Y0, i, k and D?

I'm just a neuroscientist, so forgive me if the answer to this question is either obvious, or the answer is that it is impossible, obviously. Basically, this image should outline the question clearly http://img713.imageshack.us/img713/2569/mathsissuefixedyxs.gif (And Y0 is always 1)Also, I...

I'm trying to wrap me head around what should be a very simple system, but I just can't manage it. I know there is no closed form for this problem (ignoring a voltage step like is shown in the diagram below, imagine it is a arbitrary voltage supply, or even more exactly, that R2 changes over...

Thanks again The Electrician. I'll look into convolution, and Laplace transforms.

Thanks a lot for all your help, yes, I see where I had gotten confused about the output of the opamps. I just have one question left Are the equations (R_1+R_2) \, i + R_1\, R_2\, C \, di/dt = v + R_2\, C\, dv/dt and I=Vm/Rm + C dVm/dt, Vm=Vcmd - Rs * Vm/Rm+C dVm/dt essentially...

And in a more general sense, looking at the op amps above, does that mean the output of summing amp A2 (VI)... Vi=I*Rf-Rs(Vm/Rm+C*dVm/dt)? Or more simply Vi=I*Rf-Rs*If (Again, where Vm is the voltage over the capacitor Cm)

It can't be explained by I=Vm/Rm + C dVm/dt, Where Vm (the voltage over the capacitor) Vm=Vcmd - Rs * Vm/Rm+C dVm/dt There is a bit of a debate going over here http://groups.google.com/group/bionet.neuroscience/browse_thread/thread/b1b5e00d6b5deb6f/658ba433c2e50ff9#658ba433c2e50ff9