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 [DPRG] Current Sensing -- How to Do It? Message index sorted by: [ date ] [ thread ] [ subject ] [ author ] Previous message: [DPRG] Current Sensing -- How to Do It? Next message: [DPRG] Current Sensing -- How to Do It? Subject: [DPRG] Current Sensing -- How to Do It? From: DeltaGraph at aol.com DeltaGraph at aol.com Date: Mon Jul 19 08:43:10 CDT 2010 ```Dick, Overhead video camera sounds like least number of wires? Hall effect sensor would "see" the car with no added magnet -- me thinks, but does sound expensive. Modern current detecting ICs (at least inline versions and not inductive), as far as I know, are amplifiers capable of amplifying very tiny voltage drops. Would be interesting to see cleverest way to do this sensing -- each track rail forming a complete loop around the track, each track segment reporting a slightly different voltage as the car moves around the track. I am thinking you could do differential drop voltage analysis on say a total of three points on the track to get your solution. That is, if you measured voltage at location where you are supplying the track and two other points say about 1/3 distance around track. you should be able to get your solution. Two sensors almost works, but you won't have a unique solution. You might want to draw each track conductor as a series of resistors arranged in a loop. Maybe for fun 4 resistors at 1 ohm a piece. Then maybe make the car 1 ohms for the sake of simplicity -- see what happens as you put the car in different positions and solve the network. Put the voltage supply say 10 volts at one corner, and look at what happens as you put the car resistor across each set of corner nodes. When the car is at the position of the source, all sensors read 10 volts. Of course in real life each track segment is a distributed resistance with. Anyway, I think this technique would allow you to solve for load being generated by car, if I got it right. The voltage differential measurement would be among points on one of the rails If resistances are not that predictable for real-world track, maybe you would have to experimentally test/train the system? Ron -------------- next part -------------- An HTML attachment was scrubbed... URL: http://list.dprg.org/pipermail/dprglist/attachments/20100719/23b1be4f/attachment.html ``` Previous message: [DPRG] Current Sensing -- How to Do It? Next message: [DPRG] Current Sensing -- How to Do It? Message index sorted by: [ date ] [ thread ] [ subject ] [ author ] More information about the DPRG mailing list