Lesson A short electricity lesson

A short lesson in electricity may be in order to help some of our members that are inexperienced in such maters. So I’ll give it a shot! If this has been done already, I guess another time won’t hurt.

The best way I have found to understand how electricity flows through wires is to compare it to how water flows through a garden hose. A particular diameter of hose is equivalent to a particular voltage in a wire. A particular pressure in a hose is equivalent to a particular current in a wire. When you multiply the diameter and the pressure, or the voltage and the current, you get the amount of work that is being provided.

For example, lets say you have a bucket that can be filled with either water or electricity. And lets say you need to get the bucket filled every minute in order to have enough “work” for your purpose. As long as you have enough pressure or current available, you can just turn it up until you can fill the bucket in time. But what do you do if you don’t? You have two options, use a pump that will further increase the pressure or current, or just use a larger hose or a higher voltage. A pump would add significant cost, not only for the pump itself, but also for the additional power to run it. If you have to go buy a higher voltage motor or a larger garden hose than you already have, that would significantly add to the cost too. However, if you do the proper planning ahead of time, and get the right diameter hose or the right voltage motor to start with, than the additional cost is minimal, if any. At some point even the most powerful H-bridge will reach it’s limit in current output. But if you have some overhead left in its voltage limit, then you can still get more work out of it at the same current output by using a higher voltage motor (a 24v motor takes approximately one-half the current of a 12v motor to do the same amount of work).

Another thing you may also want to consider is safety. Voltage does not kill, current does. An auto ignition system puts out several thousands of volts, but very little current. If you have ever been shocked with one by touching the spark plug wire when your vehicle is running, then you probably won’t ever want it to happen again, but at least you will still be around to tell the story! However, it only takes .5 amps of DC current or .3 amps of AC current across your heart to cause an arrhythmia. This is why AC power is more dangerous in comparison to DC. Some food for thought.

Just remember PIE: Power = current Intensity X Electromagnetic force. This is equivalent to the formula: Wattage = Current X Voltage

Note: While it’s true that as little as .5 DC amps across your heart can stop it, most people have quite a bit of resistance to it in their bodies. So for most it would take significantly more current going through their body to put .5 DC amps across their heart. For a few people though, including one of my uncles, electricity flows easily through them. My uncle can’t wear an electronic wristwatch because they quit working after he wears them for only a few days. A static electricity shock practically sends him through the ceiling. If he weren’t my own uncle, I would have a hard time believing that I admit! In fact, for several years, I didn’t! But I’m at the age now that when I think something is impossible, I don’t believe that either!

I hope this information has been conveyed in a manner that is helpful to you!

Excellent..

ZAP!!

Gotcha ... Wow ... How interesting ? ...

I'm sorry, but in this hose coefficient garden example ... you should choose from the beginning a smaller bucket to be filled in time .

Yes I found it a little confusing too, and Im not a beginner.
But if it helps more people understand it , then Im all for it.

THX for the info

Nice video! Thanks a lot for sharing this, speedy.