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Electronics => Projects => Topic started by: LabVIEWguru on April 30, 2010, 12:04:07 00:04



Title: Kelvin-Varley voltage divider under Circuit Wizard 1.5 - Help appreciated!
Post by: LabVIEWguru on April 30, 2010, 12:04:07 00:04
Gentlemen:

http://www.megaupload.com/?d=UH11O832

This zip contains an EDN article about precision voltage dividers. I've always wanted to play with something like this, and thought it would be a wonderful opportunity to try Circuit Wizard 1.5.  I laid out my virtual circuit according to diagram 1b in the article, but lacking decade switches I used DPDT switches. It looks like I've laid it out properly, but the circuit doesn't simulate like it should. If someone who is familiar with Circuit Wizard would be so kind as to have a look and see if I wired it correctly, I would appreciate it. I've looked at it a thousand times and can't see what is wrong. (that usually means I made a mistake) Many thanks.

Is there something better than Circuit Wizard to play simulation with, but not as involved as Proteus? Something "between" the two?


Title: Re: Kelvin-Varley voltage divider under Circuit Wizard 1.5 - Help appreciated!
Post by: FriskyFerret on April 30, 2010, 03:10:29 03:10
Seems to model fine in MultiSim. The virtual DVM must have an input resistance in the Gigohm range to prevent circuit loading if you're not using an output buffer. Quit messing around with whatever Circuit Wizard is.


Title: Re: Kelvin-Varley voltage divider under Circuit Wizard 1.5 - Help appreciated!
Post by: LabVIEWguru on April 30, 2010, 04:29:20 16:29
I grabbed a copy of MultiSim and will install it this weekend. No matter what virtual switches I closed, I wound up with 500-some microvolt under Circuit Wizard. I removed each stage and replaced with virtual resistors of the proper value and it didn't seem to make any difference.


Title: Re: Kelvin-Varley voltage divider under Circuit Wizard 1.5 - Help appreciated!
Post by: FriskyFerret on April 30, 2010, 08:00:28 20:00
It may be an internal math precision limitation in the simulator.