Build a Simple Amperometer *(Ampmeter)

by agis68 in Circuits > Tools

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Build a Simple Amperometer *(Ampmeter)

ampmeter0-15.jpg
how to drill the hole.jpg
Always i was wondering how many amps are the current i use in a specific circuit.

WIKIpedia says:The ampere (symbol: A) is the SI unit of electric current.The ampere, in practice often shortened to amp, is an SI base unit, and is named after Andre-Marie Ampere, one of the main discoverers of electromagnetism.

In practical terms, the ampere is a measure of the amount of electric charge passing a point per unit time. Around 6.242 � 1018 electrons passing a given point each second constitutes one ampere.[2] (Since electrons have negative charge, they flow in the opposite direction to the conventional current.)
One ampere is defined to be the constant current which will produce an attractive force of 2�107 newton per metre of length between two straight, parallel conductors of infinite length and negligible circular cross section placed one metre apart in free space. The definition is based on Amp�re's force law] The ampere is a base unit, along with the metre, kelvin, second, mole, candela and the kilogram: it is defined without reference to the quantity of electric charge.

The SI unit of charge, the coulomb, "is the quantity of electricity carried in 1 second by a current of 1 ampere.". Conversely, a current of one ampere is one coulomb of charge going past a given point per second:

\rm 1\ A=\frac{1\ C}{1\ s}

That's for the theory....
Now its time to build our very simple Amperometer...to count the current of any circuit.

MATERIALS

+For this instructable i use the analog panel of an Ampmeter from range 0-15Amps which costs around 6-7 Euro (http://www.velleman.be)
+A small box (by Velleman too) costs 4 euro
+ 2 RCA connectors female (one red and one black)
+ 2 crocodiles or pins
+ Small cables for connections and 2 large cables (up to 20cm)
+ A Dremel tool to open the big hole in the plastic box to fit the panel,some sandpaper
+ Soldering tool, Screw driver, and Some time
Total cost 10-12 euro (8-10 USD)

Building Step

work.jpg
Ampmeter.jpg
AMPMETER READY.jpg
Ok...we have all the materials we need? Lets start...Oh forgot Also we need a good cup of coffee...hehehe....So let's start...

The dimmensions of the box (iforgot to mention) are 10x4x3 and are tight enough to fit the panel meter.
So we appart the cover of the box (unscrew the 4 screws) and FIRST fit the panel meter BEFORE anything else. The panel comes with some screws and nuts but believe me this is the hardiest thing in this instructable...to fit tight the panel meter in the box.
After that with a soldering tool we have to solder the appropriate connectors, cables and RCA and crocodile tips. From each RCA starts on test cable which leads to the appropriate crocodile tip (Red to RED and Black to Black) From the RCA connectors we use ONLY the central cennector. That's it very simple and quick and reliable. Now screw back the box cover and your AMPmeter is ready for use

How to Use it

An ammeter is placed in series with a circuit element to measure the electric current flow through it.