G'day all,
Ohm's law is NOT rocket science. Newbies only need remember the formula, and how to relate to it. You need 2 facts only: Either AMPS and VOLTS or OHMS. The formula that has been mentioned before is I=E/R Where I is the current in AMPS. E (sometimes called V, which is exactly the same thing) is the voltage across the circuit measured in VOLTS. Lastly, is R, this is the circuit resistance in OHMS.
The best way to remember the formula is to draw an equalateral triangle. Draw a line horizontally across the triangle about half way down.
In the bottom section, draw a vertical line from the horizontal line to the base of the triangle.
Now you have 3 seperate compartments. In the top compartment, label it E (or V if you wish)
In the bottom left compartment, label it I.
In the bottom right compartment, label it R.
now looking at your chart you can see the 3 formulae.
I at the left = E on the top, over or divided by, R on the bottom right.
E on the top line = I at the bottom left multiplied by R on the bottom right.
R on the bottom right = E on the top divided by I on the bottom left.
Simple hey!!
If there is a need to go into capacity (of a component, EG Battery switch rating, Etc.) versus the circuits needs, then drop me a line and I will try to explain that too.
If this seems too simplistic, remember, none of us were BORN with electronics ingrained.
Regards,
Rod