How to ...

Make a HIGH power shunt for box store DVMs and

Extend the range of most box store DVMs past 10 AMP max

This technique does not apply for AC power measurement

This technique allows different props to be expressed in terms of Watts;

From FIG 2...

First measure resistance and Volts

Second calculate current, I = E1 / R1

Third calculate power, P = E2 X I

CAUTION,

lipos exhibit a potential fire and or explosion hazard if output wires short (touch each other).

Never ever allow lipo wires to touch, the lipo will dump MAX AMPs into zero Ohms, weld wires together, chemical avalanche, puff up and may burst into flame and explode.

Although I give two examples below,

DO NOT wire up these example.

DONOT wire up R LOAD equal to zero Ohms.

These examples are for other purpose.

For direct current only

>I< current, Ampere, AMPs

>E< Volt

>R< resistance in OHMs

>P< power in WATTs

I = E1 / R1 … “ / “ …. E is divided by R

P = E2 X I …. “ X ” …. E is multiplied by I

R1 is called a shunt resistor and RL the load resistor.

R1 is usually measured when the shunt is cold (FIG 1).

The shunt will get hot under test conditions and its value will change

This unknown change is critical with respect to repeatability so the shunt power handling character must be addressed.

DONOT wire this example. DONOT connect you lipo at this time.

This is an example only to define your

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