Hello everyone.
I have an array of 20x20 electrodes (a pcb with a matrix of 20x20 terminals) and I would like to be able to control each one of them separately through a computer.
How would I do that?
Thank you in advance.
Controller help needed
Apr 01, 2008
3 Replies
Do you mean control their voltage or current? Which one? How precisely? How much voltage, how much current? How fast do they need to change?
If you are, indeed, controlling their voltage or current, then you need appropriate amplifiers driving each electrode, and either each amplifier needs to be driven by a DAC or you need fewer DACs and a sample-and-hold circuit preceding each amplifier.
Whatever it is, it'll be a challenge.
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com
Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
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How much current do the electrodes require?
How is it all wired up? Do you have 20 rows and 20 columns so that one row and one column intersects at an electrode?
How quickly do you want to change which electrodes are activated?
The answers to those (and possibly other) questions will influence how to do this.
However, there are nice controller cards that you can control with software to do this sort of thing. For 40 lines, it'll be fairly expensive (maybe a couple of hundred dollars)
Regards, Bob Monsen
What voltage levels and what currents?
0-3 volts and 20mA each? If they are all on, that's still 8amps and 24 watts.What's the application?
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