Study of Generator Coil Acceleration Under Load (moderated)

[gotoluc]

Hi verpies,

you may not of noticed but the meters measuring the supplied voltage and current for the prime mover (jobmate) are set up as a Low Pass Filter.
I call it my cap bank meters which are permanently setup as a low pass filter (see pics) where the current (right DMM) is measuring the DC voltage across a 0.1 Ohm  resistor which is connected between the right 3,900uf capacitor to the left 3,900uf capacitor. The left DMM is measuring the voltage across the left capacitor which includes the voltage drop.

Knowing this I now believe you would agree the test data to be correct?

Thanks for your help

Luc

[verpies]

you may not of noticed but the meters measuring the supplied voltage and current for the prime mover (jobmate) are set up as a Low Pass Filter.

Indeed, I have not noticed.
A low Pass Filter with low enough cutoff frequency is effectively an averaging circuit.
But I would add small ceramic or film capacitors in parallel with the big electrolytic caps because big caps can have a high ESR at higher frequencies that lets those through.

The left DMM is measuring the voltage across the left capacitor which includes the voltage drop.

So the energy flows form the right cap to the left cap?

Knowing this I now believe you would agree the test data to be correct?

Yes, the input power of the prime mover was correctly calculated.

[gotoluc]

So the energy flows form the right cap to the left cap?

No, the Left cap is the DC input filling Right cap (through resistor) and why I mentioned the left DMM is measuring the voltage across the right cap since there will be a voltage drop caused by the resistor.

I also had a 100000uf cap between the prime mover and the low pass filter output cap to make sure there was a smooth transition between the two.

I agree on adding a 0.1uf across the low pass filter output cap. But for the low frequency the prime mover was I'm sure it was adequate.
I'll add it in case I use it for high frequency work.

When ever DC is being switched on and off, I always use this low pass filter metering system. I suggest everyone to build one for this purpose which makes measurements simple and accurate.

Thanks for your help

Luc

[verpies]

No, the Left cap is the DC input filling Right cap (through resistor) and why I mentioned the left DMM is measuring the voltage across the right cap since there will be a voltage drop caused by the resistor.

That's wrong.  For input power measurements purposes, the voltage should be measured AFTER the voltage drop caused by the CSR.
Otherwise you are also measuring the power dissipation of the CSR.

[gotoluc]

That's wrong.  For input power measurements purposes, the voltage should be measured AFTER the voltage drop caused by the CSR.
Otherwise you are also measuring the power dissipation of the CSR.

I don't know where the confusion is but I tried my best to describe the voltage is measured after the CSR voltage drop!

re-read the below

No, the Left cap is the DC input filling Right cap (through resistor) and why I mentioned the left DMM is measuring the voltage across the right cap since there will be a voltage drop caused by the resistor.

Luc