A3C & X-MAGNETS AND PMF.

[ageofmagnetizm]

hi Gyula,


1. input power: the drive motor has the product description and specification booklet explaining that accu has 16.2 W and 10.8 V  and 1.5 Ah, and shaft torque 15Nm - these are maximums taken into calculations.


2. digital multimeter: it also has booklet explaining how to measure electrical resistance and AC voltage - simply connecting leads to terminals and switching dial on necessary function. There are no explanations about AC or DC resistance - only electrical resistance, and there is no function for AC currents - only AC voltage, and there are no explanations about needs of additional devices such as lamps or power resistors.


Interesting is your suggestion about measuring with a load, would you please, post here a link to scientific literature where such measurements are explained such that I can learn specifics and features of such proceedings.

[ageofmagnetizm]

Hi truesearch,
thanks for encouraging me,
but I have to encourage you and other here to replication or building of similar simple experiments,
which will expand the borders of knowledge.

[gyulasun]

Hi ageofmagnetizm,

1) you surely know that a battery can be overloaded for a certain short time i.e. abused beyond its normal
ratings and if you do not monitor its output voltage and current you will not be aware of it when your generator
setup may overload it.
2) in User Manuals for digital multimeters the text does not always include the How to or What to measure
with detailed explanations etc and it is also unfortunate your meter does not have AC current measuring function.

I quote this part from you:  "Interesting is your suggestion about measuring with a load,"  you sound as if
this would be the first time you hear about such thing and I could say this is interesting when you build such setups.
In your home any electrical appliance is a load to your mains input and these appliences have a rated power
consumption and your Watthour meter registers their consumption. When you disconnect all appliences the meter
does not register consumption in your home. Your generator setup output is no exception: it provides an AC output
power when you attach a load across its output. And if you do not have a load there is no output power while your
drill still runs your setup and consumes power from its Li-ion battery.

Anyway, See this link first and please go through on it all:
https://www.electronics-tutorials.ws/accircuits/power-in-ac-circuits.html

and then I suggest the followings: use a power resistor as the LOAD across your output coil.  Because you will
know the Ohm value, you can really calculate the power dissipated in it by the formula V²/R and no problem your
multimeter has no AC current measuring function, it is not needed in this case: just measure the AC voltage
across it and then use the formula.

Very likely the RPM of your drill will be reduced the moment you connect the load resistor to the generator
output coil or at least that is what is expected in most setups, I wish you should not experience that in your setup.
If you do, then you would need to check input current and voltage to your drill to get a meaningful efficiency test.

Why I suggest the use of a power resistor: it has a known resistance so it loads your output coil with a constant
value unlike to say an incandescent lamp which has a nonlinearly changing resistance in function of the voltage across it.

Your output power measuring method can exactly be the same like measuring AC power taken from either
the mains or from the secondary coil of a mains transformer, you can find many explanations on AC power
measurements at Wiki or elsewhere.

Because you cannot measure AC current with your present multimeter that is why the use of
a known load resistor is needed.

See Figure 2 in this link http://www.bristolwatch.com/ele/transformers.htm where power measurement
is explained in a mains transformer: an AC ampermeter is shown in series with load resistor R1 in the secondary
coil too. Your generator output coil corresponds exactly to the secondary coil of this transformer when
its output power is to be measured. But you will choose a known R1 load resistor so that you can use
V²/R1 formula for output power by measuring only the AC voltage across R1. 

Gyula

Edited to make text lines less wide

[ageofmagnetizm]

for gyulasum,


here is the picture of multimeter inner smart components, there are small battery and small loudspeaker and smal but smart electric circuits allowing fast and simple measurements of electrical resistance and output AC voltage which are necessary for calculation of power output.


and here is link to article on Wikipedia explaining how multimeters function when measuring:


https://en.m.wikipedia.org/wiki/Multimeter


Alternating current sensing
Since the basic indicator system in either an analog or digital meter responds to DC only, a multimeter includes an AC to DC conversion circuit for making alternating current measurements. Basic meters utilize a rectifier circuit to measure the average or peak absolute value of the voltage, but are calibrated to show the calculated root mean square (RMS) value for a sinusoidal waveform; this will give correct readings for alternating current as used in power distribution. User guides for some such meters give correction factors for some simple non-sinusoidal waveforms, to allow the correct root mean square (RMS) equivalent value to be calculated.

next week I'll wright more about how and why I"ve published such measurement and some more about other measurements, but for now read about multimeter and the rectifier circuits build inside of the device:

https://en.m.wikipedia.org/wiki/Rectifier

and have a nice weekend too...

[gyulasun]

What you write as quoted on multimeters sounds ok BUT has nothing to do with the fact that
you have not used any load across your generator output coil to estimate output power.

You seem to be really lacking the needed understanding of this neasurement topic in electronics.

I wish you good luck in your endeavours.

Gyula

PS if you reduce your uploaded picture size to have a max of 900 to 1000 pixels horizontally,
instead of the 2048 pixels,  then we do not have to scroll horizontally back and forth to read the posts.