Watts it all about Alfie

Before we start, please don’t immediately lose interest, because everyone, even you, can do this.

How to simply work out Watts, Amps, Volts.

When I was at school during the late 1940’s and all thorough the 1950’s I was hopeless at maths, and was considered to be thick as sh-- / two short planks because I am dyslexic, and tend to read figures as something totally different to what is written down.  2471 would probably appear to me as 2174 no matter how many times I looked at it or wrote it down I would get it wrong.  Even today I frequently dial incorrect telephone numbers because my tiny brain reads the number differently.  So what do I do then?  Yes that’s right I double check the number and dial exactly the same number  I dialled before!!   Often resulting in an ear full of abuse, which is mostly all I ever got at school, and also from my well versed, intelligent, grammar school educated father, who tried to shout and beat maths into me for a couple of hours most evenings after school.  My teacher used to throw sticks of chalk at me and ridicule me in front of the class, and if he was really angry, would throw the wooden cased black board eraser at me, when all I could see was a blur of figures and mathematical signs.  If all that failed, which it invariably did, I would then get a whack around the head, and be given 500 lines to do during the break time. The result was the teachers never had time for me and I was left way behind, a hopeless case destined to become a road sweeper or bin man.  Seriously that is what I was told and how it was.  It would have been far better to have kept me behind and for the teacher to explain things in a language I could relate to, than have me sitting there writing useless lines like “I must pay more attention to my school work” 500 times which he had to supervise anyway ! And then throw them straight in the bin!  What in God’s name did that ever do for me?

Most of that would have been basic maths and the dreaded long division, so I never had a chance in hell when it came to algebra with meaningless formulas which were never really explained properly.  The bright kids picked up on it and they are the ones the teachers focused their attentions on rather than wasting time trying to get through to me.  But what about all, yes, all the years at school that I wasted instead of learning something that later in life would have been useful to me, because what little I know now, I basically taught my self!   

I’ll never make a teacher, but I have cut out all the crap of equations and mathematical language that everyone expects us to know, and most of us pretend we do because we don’t wish to look stupid by asking, so I am saying it as it is!  If you still don’t understand, please don’t be afraid to ask, and I’ll be pleased to look it up for you :- )  I later decided to put the equations in brackets in red just to show how they normally look.  I is current or amps.  V is volts. P is watts meaning power. R is resistance measured in Ohms.  V/I is V over I meaning volts divided by amps.  I R  happens to be  amps by resistance meaning amps times resistance.  They leave out the times sign X to avoid us getting confused because we can clearly see the  I is by (near) the R so why bother with I X R ?  I n this instance the question mark ? is not part of the equations we are dealing with here, I would hate to confuse you even more!  That goes for the exclamation mark too.

 For all these calculations there are three components. Volts Watts & Amps.  From any known two (which are called the constants) we can easily figure out the other.  I.e. If we can measure the voltage and the current, we can work out the Watts.  I’ll leave in the equals sign " = " as I’m sure we will all know what "equals" means.  Don’t we?

Here we go then.  On the first example we seem to know that we have 12 volts and 12 watts, so watts the current?  'Scuse the grammar old chap !

12 watts divided by 12 volts = 1  which is 1amp.  Is that right or what or watt eh !  Believe me it is.

Amps to Watts

Convert:   Amps to Watts from a known or measured voltage. 

Watts = Amps times Volts  (P = I V)

Example:  1 amp times 240 volts = 240 watts.  (Piece of piss or Watt ? What?)

Watts to Volts

Convert:   Watts to Volts from a known current or amperage, amps.

Volts = Watts divided by Amps  (V = P /I)

Example:  100 watts divided by10 amps = 10 volts

Volts to Watts

Convert:  Volts to Watts from a known current or amperage, amps.

Watts = Amps times Volts  (P = I V)

Example:  1.5 amps times 24 volts  = 36 watts  (Watt it can’t be that easy, can it?)

Volts to Amps at a known wattage

Convert:   Volts to Amps where the Wattage is known.

Amps = Watts divided by Volts  (I =P /V)

Example:  600 Watts divided by240 Volts = 2.5  Amps

Amps to Volts at a known Wattage

Convert Amps to Volts where the Wattage is known.

Volts = Watts divided by Amps  (V = P/I)

Example:  600 Watts divided by 2.5 Amps =  240 Volts ( well blow my fuse)

Volts to Amps through a known resistance

If you know the voltage measured across a resistance measured in Ohms, which we’ll call the load, the amps we can work out by “Ohm's law”:

Amps = Volts divided by the Resistance.   (I = V/R)

Example:  Amps = 30 volts divided by 100 ohms = 0.3 amps or 300 ma.

Amps to Volts through a known resistance

If you know the amps and the resistance, then according to Ohm's law,

Volts = Amps times Resistance  (V = I R)

Example:  0.3 Amps times 100 Ohms = 30 Volts.

 That really is all there is to it, so why the hell professors and all those clever buggers have to make it all so complicated, can only be to make the simple man look more stupid than I actually am.  The old adage is that bullshit baffles brains and no matter how stupid or thick you or I may appear to the “educated” we all have a brain in there somewhere.  I personally think they don’t want you and I to know what they do because for one they couldn’t look down on us and we would have no one to look up to.

 When you actually understand the maths, it is really is very interesting.  Or so they tell me. :- )
You have to want to learn not be forced to learn, and when you see good reason to learn you will want to learn, and enjoy doing so.

 I hope you enjoyed this article and were able to make sense of it.  If you did, I'll try to add some more later. 

     Here is the basic Ohms Law symbol, which otherwise looks like this.

V/I R   We are expected to know what it all means, but how many of us actually do?

Well I never did either, so in the next article to come I will explain what little I do know in simple plain English which should help us understand what they don’t really want us to know.


John Beer June 2012