What is Ohm's Law?

What is Ohm's Law?
Posted in: Vaping Advice

Ohm’s Law

Ohm's Law is a formula used to calculate the relationship between voltage, current and resistance in an electrical circuit.

You might be asking what this has to do with vaping? Ohm’s law is very important to enjoying a safe vaping experience. Ohm’s law is particularly helpful to understand if you build your own coils.

Geek Vape Zeus X Mesh WireGeek Vape Zeus X Mesh Wire
Geek Vape Zeus X Mesh Wire

Do I Need to Know Ohm’s Law?

Ohm’s law isn’t an essential piece of knowledge for most beginner vapers. If you use a disposable, pod system or a basic vape pen, then you could vape happily for years without ever having to hear about Ohm’s law.

You only really need to start understanding what Ohm’s law is when you start vaping with an RDA (Rebuildable Atomiser) or when you start building your own coils.

Making your own coils is a delicate process. It is very important to do it right otherwise the electrical resistance can run through your vape device which could be potentially dangerous.

Can Ohm’s Law Affect Your Battery?

In the simplest of terms, Ohm’s law states that if the electrical resistance in your vape device drops, the power running through your e-cig goes up.

If your vape’s resistance drops too low (by using an incorrect coil, for example), the increase in power could potentially push your battery beyond its safe limits. Using incompatible coils and overworking the battery beyond what it is capable of can be dangerous.

What is an Ohm?

The symbol for Ohm is and is short for omega. Ohm is named after German physicist and mathematician Georg Ohm. Georg Ohm was the man who discovered Ohm’s law over two hundred years ago. If you have been looking at coils for a while, you might notice this symbol on the side of your coil. Or if you use a box mod, you might recognise it from the settings panel on your device. You might also hear people talk about sub-ohm vaping. This is when the resistance of a coil is less than one ohm.

Ohm’s are used to measure the resistance of an electrical circuit. In order to understand resistance, it is a good idea to know a little about voltage and current. Electricity is measured in a number of different ways.

  • Current: The current is measured in amperes (A) which is the rate of flow of electricity through a circuit. It is easier to think of it as the ‘speed’ of electricity running through your device.
  • Voltage: Voltage is measured in volts (V) which is the amount of electricity in a circuit. When you push a coil into your device and press the fire button, the voltage in your battery is what causes the metal coil to heat up and vaporise your e-liquid.
  • Wattage: Wattage is measured in watts (W) and this is a combination of the current and the voltage (current x voltage = wattage).
Smok TFV9 Coils / Meshed 0.15OhmSmok TFV9 Coils / Meshed 0.15Ohm
Smok TFV9 Coils / Meshed 0.15Ohm

Why is Ohm’s Law Important in Vaping?

Every vaping device is made up of conductors and insulators. Conductors are found in components such as the heating coil, wiring and battery contact points. These are in place to ensure that the electricity gets where it needs to go. The insulators on the other hand are found in the battery casing and the mouthpiece. These insulators will protect you from getting an electric shock when you vape.

When you buy a genuine vape device in the UK, each kit has been made so that the power in the battery perfectly balances with the resistance of the coil. Because of this, all you ever need to do is hit the power button or inhale to access your favourite flavours.

If you have decided to build your own coils there is a number of factors that have to be taken into consideration. You can choose the type of metal that your coil is made out of. When you do this, the current and voltage levels running through your battery will change. If your battery is exposed to a current higher than it was designed to cooperate with, then it could be dangerous. This is why it is important to understand Ohm’s law when building your own coils.

Using Ohm’s law, you can design the resistance of your coil to match your battery’s voltage and current settings.

Calculating Ohm’s Law

One of the easiest ways to calculate Ohm’s law is by using a formula triangle. Ohm’s law states that the voltage in your device, divided by the resistance, equals the current. Using this formula, if you know your voltage and the resistance you will be able to calculate your current to make sure it is within the safe range for your battery. To figure out the formula, all you have to do is cover the component that you need to work out.

It is always a good idea to double-check with an expert before experimenting with your coils. If you are not 100% sure that it will work, it is not worth risking it.

It is always a good idea to double-check with an expert before experimenting with your coils. If you are not 100% sure that it will work, it is not worth risking it.

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