Electrical Resistance 101

[KentA]

If electrical resistance produces heat, how can low ohm builds produce more vapor?

 

[roxynoodle]

Resistance is the opposition of current. Our coil(s) are acting as resistors in a DC circuit.

Its actually joules that measure heat. A joule is one watt per second.

 

[HauntedMyst]

From simple wikipedia "The resistance of a wire increases as it becomes longer and decreases as it becomes wider. (A simple analogy is a road - the more lanes there are, the less traffic there is.)"

So with most low ohm builds, you have a shorter, generally fatter wire carrying a lot more power.

Think of it this way:
32g wire = The French Resistance
24G wire = The Americans coming to save their @sses

 

[Mooch]

The heating of the coil increases as the current goes up. In fact, it increases with the square of the current, i.e., Heating = (Current-squared) times (Resistance). This allows for big jumps in heating with relatively smaller jumps in the current.

Let's say you have a 1 ohm coil with 10A flowing through it. Then you have 10A * 10A * 1 ohm = 100W of heat.

If you drop the resistance to 0.5 ohms then you will have 20A flowing through it (using ohms law, assuming same voltage). The power (heating) is now 20A * 20A * 0.5 ohm = 200W.

So by halving the resistance you let more current flow. The increase in current increases the power (heating) at the coil, which makes the coil hotter, which can make more vapor.

 

[KentA]

Thank you.