This table displays how the resistance value of the shunt (R2) drains power if it is too high.
Also you can see how small the voltage drop gets if the resistance is to low, what makes it hard to measure.
{| class="wikitable"
|-
! I (total)
! U (total)
! R1 (load)
! R2 (shunt)
! U1
! U2
! P(lost)
|-
| 0,25A
| 5V
| 10
| 10
| 2.5V
| 2.5V
| 0.625W
|-
| 0,25A
| 5V
| 19
| 1
| 4.75V
| 0.25V
| 0.0625W
|-
| 0,25A
| 5V
| 19.9
| 0.1
| 4.975V
| 0.25V
| 0.00625W
|}
==How to measure==