ok i have 2 volt meters that show votage and voltage under load so i was messing around with them. i started just seeing what my 5v was putting out got 4.8, 5.2, 5. then i put an atty on it and got 4.14, 3.87, and 3.8. ok i kind of understand why that happens but thats not the confusing part. i then added a second volt meter on top of the first one and got 5.5 and 6.2, 5.9 and 5.8, 5.4 and 5.8. now when i put an atty on top of that i got 3.79 and 4.39, 4.05 and 3.53, 4.0 and 3.64. all of these last numbers are ordered from battery to atty. why would the numbers jump above 5v when just the 2 meters are on it? or is it just them reading wrong because there is 2 in a row?
smart peoples, please explain
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[bump] I would be interested in any comments / explanations of this also. Along similar lines...what is the typical measured voltage for a mod under load...is ~3.8 - 4V typical for 5V under, say, a 3 ohm load?
Putting a meter on actually changes the circuit because you are putting a resistance in parallel.
The act of placing a meter on the circuit actually changes what is happening. Now you are placing two altering devices together, so you should expect to have even more inaccurate readings.
Exactly what is happening, I may be able to explain if I knew exactly what type of meter it is. A simple resistance type meter, or an amplified type meter. Or a combination of the two. How well versed in DC electronics are you? Do you have access to an O-scope?
Or, to put it simply, using two different devices to test a circuit, at the same time, is a guarantee that you will not have good results. (Unless the effects of each device are accounted for, which is a bit more complicated than just hooking up leads.)
(Yeah, I spent too much time in the lab during EET classes...)
The act of placing a meter on the circuit actually changes what is happening. Now you are placing two altering devices together, so you should expect to have even more inaccurate readings.
Exactly what is happening, I may be able to explain if I knew exactly what type of meter it is. A simple resistance type meter, or an amplified type meter. Or a combination of the two. How well versed in DC electronics are you? Do you have access to an O-scope?
Or, to put it simply, using two different devices to test a circuit, at the same time, is a guarantee that you will not have good results. (Unless the effects of each device are accounted for, which is a bit more complicated than just hooking up leads.)
(Yeah, I spent too much time in the lab during EET classes...)
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