Accuracy of hand calculations, software and multimeters for circuit analysis

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When analyzing a circuit which is more accurate: Using hand calculations, software calculations or using multi-meter. Which one should be relied upon the first?
 
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AchillesWrathfulLove said:
When analyzing a circuit which is more accurate: Using hand calculations, software calculations or using multi-meter. Which one should be relied upon the first?
What are your thoughts? And what do you mean by more accurate? Would your hand calculations or multimeter measurements include a Monte Carlo analysis? And how long would that take? :smile:
 
All are subject to operator error. But the multimeter would be best by that measure.
Also, the multimeter will measure the circuit as implemented - so if the voltage is suppose to be 5.00VDC and multimeter says 5.02VDC, the difference is between the circuit as designed and the circuit as built. Which one are you interested in?

If you are interested in the circuit as designed, and you are willing to do cross checking, then the software will give you the most precise and reliable results. But you have to know how to good sanity checking.
 
None is the best, each has it's place.

Hand calculations decide the magnitude of components in possible solutions to circuit dreams.
Computer simulation of possible circuit solutions should confirm your ideas, and helps settle values.
A voltmeter quickly verifies that your circuit conforms to design and simulation expectations.

Later, a multimeter helps identify where the design errors, manufacturing faults or later component failures lie.
 
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Paper first: based on that you should have some understanding on the required accuracy/depth. The comes some simulation if it will be a difficult piece.
If it is something simple, straight then just build it and confirm with a multimeter/oscilloscope.
 
AchillesWrathfulLove said:
When analyzing a circuit which is more accurate: Using hand calculations, software calculations or using multi-meter. Which one should be relied upon the first?
It all depends ... .
Calculations. based on theoretical values are very different in principle from building and measuring some feature of the circuit's performance. Every element in a built circuit will have a tolerance specified, which will indicate what variations to expect in the final circuit if you carry out an analysis for all combinations of component value spread. That could take for ever but you can sometimes shorten the process by knowing what elements will have most effect. For instance, the feedback components will take care of variations in many other parts of the circuit- but it's not something I'd want to do by hand every day.
Otoh, measuring the circuit characteristics with a MultiMeter will only tell you what happens for just one set of component values. That may be fine if all you wanted was to know the characteristics of just one particular circuit board but it would not be a good basis for carrying on with production of a large number of circuit boards.