How to build current reading circuit?

Question

I was wondering, how would someone build a circuit that would read current?

Answer 1

use electrical induction...

wrap a low impedance coil around the wire to be measured...the induced voltage in the coil will be proportional to the current flow...little impedance will be 'reflected' back to the current you are measuring...

happy trails!

Answer 2

You mean an ammeter?

it depends on the cost, accuracy, portability need.

Basically an ammeter is a voltmeter measuring the voltage across a very small value resistor.

If you have a 0.1 ohm resistor, 1 amp through it would give you a voltage drop of 0.1 volts, which could be read by a digital meter or an analog galvanometer.

But your question is "how".  And the answer is with a schematic, experience, components, and a soldering iron.

.