What is electric current???
(alternating current)
ELECTRICAL CURRENT
As we explained in our last post, voltage in an electrical system is analogous to pressure in a water system. In a similar manner, current in an electrical system is flow in a water system. We used the analogy of a water hose and demonstrated how you can test for pressure by placing your finger over the end of a dripping hose. If you leave your finger off of the end, and the water drips out, that dripping is the flow in the system. Similarly, electrical “current” flows.
As an aside, current flow is made up of electrons, moving past a particular point. Just as we classify water flow in gallons per minute, we classify current flow in terms of the amount of electrons which flow past a point. Specifically, one coulomb of electrons in one second is equal to one ampere, where a coulomb is a really big bunch of electrons, probably more than we want to count. This leads to a problem of how to measure amps since we really don’t want to count all those tiny electrons. In order to measure amps we will need some kind of amp meter. There are many types, but primarily two main types. First is a multimeter which has the capability of measuring amps, and the second most common type is a “clamp on” type, with spring loaded jaws which clamp around a wire which is carrying the current we need to measure.
Both of these common amp meters are readily available at hardware stores such as Home Depot, or Sears. A multimeter can measure amps, but to do so you must break the circuit by cutting the wire and inserting the meter into the circuit. The main advantage of the clamp type meter is that you don’t need to break the circuit. You simply clamp the meter around the wire and set the meter scale to read the current flowing in the circuit.
Summary: current in an electrical system is the flow of electricity through a wire. We can measure the amount of current flow with several different kinds of meters.
(direct current)
Our next “lesson” will be about electrical “POWER”.
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OK, so now I have a very basic understanding of the flow of electricity, or should I say, flow of electrons, so now….what do I do with it?
An ‘amp meter’ will likely be called an ammeter at the store.
wyalusingwillie, thanks for the comment. The first several lessons on this portion of the blog are designed to introduce a common vocabulary that we will be building on in the future. I realize much of what I am talking about is basic and may even be boring to those who have some electrical experience. I want to have everyone on the same page when we move ahead later on. Hopefully you will continue to follow the blog when we get into some of the troubleshooting techniques later on.
Larry
2oldman, you are correct, the device we use to measure electrical current can be referred to by either appellative, amp meter, or ammeter. I intentionally used the two separate words in an attempt to make it more clear what I was describing. Hopefully you will stick with me through this series, I can use all the help I can get.
this is very educated stuff and i would like to know more
please send me about electric current
about electric current