Ohm's law
- Thread starter Mecca
- Start date
- th_trl_thread_readers 0
- Status
It just shows the various formulas that could lead to the variable in the center quadrant!
Choose the formula for what you want to solve for (the single variable in the inner quadrant, what you want to since for, has its corresponding formulas in the outter quadrant). Plug in known variables. Solve.
I would figure I didn't need to explain that because it's simple algebra which is taught from like the 6th grade and up. But that's a while different topic of where the education system fails...
Yay, my favorite bondage cartoon of ohms law.
It's actually not too bad... Let me explain...
First you have to figure out WHAT you want to solve for... or what you want to know... So let's just say we see some guy who is going on about his .18 ohm build on his EFest battery that's really only 20A continuous... (Yes I know, with enough experience you already know it's not safe, but let's just say we wanted to know for sure, or be able to explain exactly why... So what we want to know is the current his build will draw... The Amps... represented by "I" in the chart... We find what we want to solve for in the "inner" part of the wheel... So we are working in the upper right corner of the wheel...
Now, we have three different equations for that quadrant... V /R, P / V, and sqrtP / R... So now we just have to pick one that we know the variables for... We know his battery is 4.2v fully charged... and we know his resistance is .18... So I = 4.2 / .18...
Get it? If instead we wanted to find out how many watts he was generating, we choose the upper left quadrant... Of those formulas, (without calculating the above first) we know the P = V^2 / R... So again we can figure it out...
Lol! I love that because it is so true. Only thing I don't like is that some could misinterpret and think resistance is an external force.
To anyone who doesn't get this, I'll explain.
Current (amps) is the flow of electricity, just the same as current in a river in relation to water flow. The more current, the faster it moves along the wire/conductor etc.
Every bit of matter in this world has a resistance. Obviously resistance is exactly that, a resistance; it makes it harder for current to flow freely. Voltage is electrical pressure, so it kicks the current to keep moving along and overcome the resistance.
Ohm's Law is : V = I x R
v= volts
I = amps (current)
R = ohms (resistance)
For our purposes: power = v x I
and the more practical version of ohms law for us is:
Power = V x V / R
The power basically measures how hot or how much fog you're going to make.
V = voltage, and R = resistance.
the higher the voltage or the lower the resistance, the more fog or the hotter the fog you're going to get.
One nit pick... I don't like to use the term "speed" when referring to current... Because at a fixed voltage the speed at which electrons drift will remain the same. The number density of conducting electrons within the conductor does as well. Thinner pieces of conductive material (i'm speaking of a normal carbon resistor for simplicity) result in less current, but the "speed" remains the same...
The "interstate" example is the best way I have thought of to explain... If you have a fixed 3 lane interstate with cars traveling down it bumper to bumper... The number of cars per feet of roadway remains the same, but as you add or take away lanes you will get more or less cars passing any given point at any given time... Reduce to one lane and you get a third of the cars... Increase to six lanes and you have twice as many... However, their speed remains constant at 55mph...
I'm just trying to keep it super simple for those who don't understand it all. No need for complexity and nit picking.
A high school teacher once told my class to always keep it as simple as possible and to know when the details are truly necessary; don't add them in if the point can be made in a simpler manner. I try to apply the same to everyday life, because I've learned people won't listen to or read anything that is long and dull. The technical jargon doesn't appeal to everyone.
AzPlumber said:
Blah blah blah blah. Sorry, but I got an overall grade of D- in high school Algebra I over forty years ago. The next year I got an B in Business Math. Go figure. Somehow I got through college to earn an Associate Degree in Applied Science despite my struggles with math, physics, and chemistry.
I can input the information into an Ohm's Law Calculator, which basically does what your explanation does. So that's even easier than your hierogliphic Ohm's Law Circle.
To find the voltage to use in a regulated mod, I take the coil resistance of my atomizer and add the number two. The sum equals the voltage range to use with that resistance.
2 ohm coil
+ 2
4 volts
Last edited:
to digest that ! (No, really very informative, bringing back my long lost physics 101) thanks guys.
I hope there is no test! 25 years ago in my high school, business classes is what "the girls" took. I could create a balance sheet in 2 minutes make copies on the mimeograph machine, and type 80 wpm AND take shorthand! Where do you thing I applied those skills? Now I wish I took the standard college courses! never had algebra, physics, certainly would come in handy now. LOL
- Status
Similar threads
- Locked
- Locked
