In the first post of this guide I will be going through the theoretical details of how electricity behaves in the coils we use in our devices.
Disclaimer: To an extent I will oversimplify some concepts. To avoid the vehemence of fellow physicists, I will simply state now that this guide is meant for novices to electrical concepts. This means that some things I say here are not completely true, though I will endeavor to keep things as close to the absolute truth as possible. If I was to try to give a completely true account of this theory, it would involve degree level knowledge of quantum mechanics.
Contents:
1.0 Defining and Explaining Terms
1.1 Coulomb
1.2 Voltage
1.3 Amperage
1.4 Resistance
2.0 The transfer of electrical energy to heat energy
3.0 Ohms Law
4.0 Power
1.0 Defining and Explaining Terms
For the purposes of this guide we will view electricity as a flow of electrons through a wire. While this is not entirely accurate, it is unnecessary to view it as anything other to explain these concepts.
1.1 Coulomb (C)
When describing electrical concepts such as voltage and amperage, we are describing attributes of the particular flow of electrons in the coil. Electrons are very small and very numerous, if we tried to talk about everything in terms of exact numbers of electrons, the numbers would get huge and thus unintelligible very quickly. Thus the coulomb, it is a constant, a set number of electrons. To be exact, it is 6.241 x 1018 electrons.
1.2 Voltage Volts (V)
Voltage, measured in volts, is a description of the amount of energy one coulomb of electrons can transfer. It comes in many forms, sometimes called potential difference, sometimes described as electromotive force, for our purposes we will simply refer to it as voltage.
The more voltage a packet of electrons contains, the more oomph it has, the more energy it can deliver, the more of a zap you would get if subjected to it.
1.3 Amperage Amps (I)
Amperage (aka current), measured in amps, is a description of the number of coulombs of electrons pass through a point in one second.
Therefore, the more amps a device is outputting, the more electrons it is putting out per second. This is why many batteries have amp ratings, some can only put out so many electrons per second, depending on their chemistry.
1.4 Resistance Ohms (R)
Resistance is a strange concept. The fire hose is a common, and very useful way to understand it, I wont break with tradition.
Imagine a fire hose and garden hose. Water flows through the hoses just as electrons flow through a wire. The thinner the hose, the harder it is for water to flow through the hose. The thicker the hose, the easier it is for water to flow. The hose is a resistor to water flow, just as a wire is a resistor to electron flow.
There are quite a few factors that influence the resistance of a wire:
2.0 The transfer of electrical energy to heat energy
As electrons flow through a wire they flow with more or less a fixed speed. As an electron encounters resistance, in the form of the atoms arranged in the wire, the electrons must give up some energy in order to get past this resistance.
An analogy for this is to imagine a car driving down a road. On nice clean tarmac a car uses comparatively little energy to drive down the road. If you now cover the road in water (which resists the cars passage) the car must now use more energy to drive down the road at the same speed. If you cover the road in mud, it must use even more energy to drive at the same speed. An electron is similar to a car in this way, some arrangements of atoms are harder for the electron to pass, the electron must thus give up more energy in order to get through.
In both cases, the electron and the car, energy is always conserved. This means that it doesnt just disappear, it has to go somewhere. In the case of the electron the extra energy used is passed on to the atoms it is getting past. This extra energy results in the atoms vibrating more. The faster an atom vibrates, the higher its temperature.
So to summarize, when an electron loses energy by passing a resistance, the energy is absorbed by the atoms, resulting in a higher temperature.
Now, what is going to result in more heat transfer? More voltage, or more amperage?
To answer this question, we can think of the atom arrangements in the wire as a series of energy toll booths. At each toll booth along the road, the electron must pay some energy in order to get past. This happens regardless of how much energy the electron has (voltage). So, lets use some completely crazy numbers to explain this.
Imagine a wire with five energy toll booths, each toll booth has an energy fee of one joule. One electron with ten joules of energy passes through this series of toll booths. At the end of its passage it will have paid five joules of energy. Now imagine five electrons passing through the same series of toll booths, each electron will have to pay five joules to get through. So five electrons, each paying five joules, will result in a total payment of twenty five joules of energy.
Thus, amperage (the number of electrons passing per second) is far more important than the voltage (the amount of energy each electron has) with regards to how much energy is transferred to a coil.
So why do we adjust voltage on VV devices, and get a different vape experience? This is due to Ohms law.
Unfortunately the reason for this law is quantum mechanical and is thus very complicated, so for the purposes of this guide it would be impractical to try and explain it.
The law can be expressed in various, equally valid mathematical statements:
Voltage = Amperage * Resistance or V = I*R
Amperage = Voltage / Resistance or I = V/R
Resistance = Voltage / Amperage or R = V/I
The official (if there even is one) statement of ohms law is that the current through a conductor is directly proportional to the voltage across the conductor, where the constant of proportionality between the two is the resistance.
This has a couple of implications that are important to vapers:
Usually when this law is used by vapers, it is used to calculate amperage, in order to ensure that the build used is safe for the battery.
To give some examples:
a) Your battery is rated at 10 amps max output and you build a 1.2 ohm coil. On a full charge most batteries output 4.2 volts.
Amperage = Voltage / Resistance
Amperage = 4.2 volts / 1.2 ohms
Amperage = 3.5 amps
Since the 3.5 amps required by the build is less than the 10 amp maximum of the battery, this would be a safe build to use.
b) Now say you again have a battery rated at 10 amps max output, but this time you build a 0.4 ohm coil.
Amperage = Voltage / Resistance
Amperage = 4.2 volts / 0.4 ohms
Amperage = 10.5 amps
Now the build will draw 10.5 amps and the battery is only rated for 10 amps, this would be a dangerous build.
There are various ohms law calculators you can use if you are scared of messing up the maths. On both android and apple devices you can simply search ohms law calculator on the app store.
On a pc you can use Ohm's Law Calculator
On most of these apps you could just plug in the voltage (almost always 4.2) and the resistance of your coil. Hit the calculate button and the results will pop up.
4.0 Power
Power, measured in watts, is a description of how much energy a particular flow of electrons can deliver. It is a combination of voltage and amperage. Mathematically the relationship is described as:
Power = Amperage * Voltage or P = I * V
Examples:
a) A coil draws 2 amps from a mech mod battery (4.2 volts max).
I * V = P
2 amps * 4.2 volts = 8.4 watts
b) A coil draws 4 amps from a variable voltage device set at 3.8 volts
I * V = P
4 amps * 3.8 volts = 15.2 watts
The above formula can be substituted into ohms law to yield two further useful formulas:
Power = Voltage2 / Resistance or P = V2 / R
Power = Amperage2 * Resistance or P = I2 * R
The most commonly used power formula for vapers is the one relating power, voltage and resistance. This is because it is very easy to tell what voltage a battery is supplying.
Examples:
a) A battery in a mech mod (4.2 volts max) is connected to a 0.8 ohm coil.
P = V2 / R
P = 4.22 / 0.8
P = 22.05 watts
b) A variable voltage device is set to 3.6 volts and is connected to a 1.2 ohm coil.
P = V2 / R
P = 3.62 / 1.2
P = 10.80 watts
And this ends the theory portion of this guide.
I hope this all made sense, if you have any questions please feel free to leave a question and either myself or another knowledgeable person will be sure to respond.
Happy vaping!
Disclaimer: To an extent I will oversimplify some concepts. To avoid the vehemence of fellow physicists, I will simply state now that this guide is meant for novices to electrical concepts. This means that some things I say here are not completely true, though I will endeavor to keep things as close to the absolute truth as possible. If I was to try to give a completely true account of this theory, it would involve degree level knowledge of quantum mechanics.
Contents:
1.0 Defining and Explaining Terms
1.1 Coulomb
1.2 Voltage
1.3 Amperage
1.4 Resistance
2.0 The transfer of electrical energy to heat energy
3.0 Ohms Law
4.0 Power
1.0 Defining and Explaining Terms
For the purposes of this guide we will view electricity as a flow of electrons through a wire. While this is not entirely accurate, it is unnecessary to view it as anything other to explain these concepts.
1.1 Coulomb (C)
When describing electrical concepts such as voltage and amperage, we are describing attributes of the particular flow of electrons in the coil. Electrons are very small and very numerous, if we tried to talk about everything in terms of exact numbers of electrons, the numbers would get huge and thus unintelligible very quickly. Thus the coulomb, it is a constant, a set number of electrons. To be exact, it is 6.241 x 1018 electrons.
1.2 Voltage Volts (V)
Voltage, measured in volts, is a description of the amount of energy one coulomb of electrons can transfer. It comes in many forms, sometimes called potential difference, sometimes described as electromotive force, for our purposes we will simply refer to it as voltage.
The more voltage a packet of electrons contains, the more oomph it has, the more energy it can deliver, the more of a zap you would get if subjected to it.
1.3 Amperage Amps (I)
Amperage (aka current), measured in amps, is a description of the number of coulombs of electrons pass through a point in one second.
Therefore, the more amps a device is outputting, the more electrons it is putting out per second. This is why many batteries have amp ratings, some can only put out so many electrons per second, depending on their chemistry.
1.4 Resistance Ohms (R)
Resistance is a strange concept. The fire hose is a common, and very useful way to understand it, I wont break with tradition.
Imagine a fire hose and garden hose. Water flows through the hoses just as electrons flow through a wire. The thinner the hose, the harder it is for water to flow through the hose. The thicker the hose, the easier it is for water to flow. The hose is a resistor to water flow, just as a wire is a resistor to electron flow.
There are quite a few factors that influence the resistance of a wire:
- Thickness This is well described by the fire hose example. The thinner the wire, the less room there is for electrons to manoeuvre. The thicker the wire, the more room, thus, with a thicker wire more electrons can flow at the same time.
- Length The longer a wire is, the more resistance the electrons will encounter along their path. This is why most resistance wires are rated with a resistance per inch value.
- Material Different wires types are made out of different materials. Different materials have different chemical compositions and as a result, the atoms are arranged differently. This different arrangement makes some wires harder for electrons to pass through them, while in others it makes it easier.
- Temperature The more the atoms in a material vibrate, the harder it is for electrons to pass through the material. As a result of this the higher the temperature of a coil, the higher the resistance. Due to the very rapid transfer of heat from coil to juice however, the temperature of coils remain more or less constant, and thus, temperature is not so great of a factor. It is for this reason however, that it is important when dry burning a coil to pulse the battery rather than supply a continuous current.
2.0 The transfer of electrical energy to heat energy
As electrons flow through a wire they flow with more or less a fixed speed. As an electron encounters resistance, in the form of the atoms arranged in the wire, the electrons must give up some energy in order to get past this resistance.
An analogy for this is to imagine a car driving down a road. On nice clean tarmac a car uses comparatively little energy to drive down the road. If you now cover the road in water (which resists the cars passage) the car must now use more energy to drive down the road at the same speed. If you cover the road in mud, it must use even more energy to drive at the same speed. An electron is similar to a car in this way, some arrangements of atoms are harder for the electron to pass, the electron must thus give up more energy in order to get through.
In both cases, the electron and the car, energy is always conserved. This means that it doesnt just disappear, it has to go somewhere. In the case of the electron the extra energy used is passed on to the atoms it is getting past. This extra energy results in the atoms vibrating more. The faster an atom vibrates, the higher its temperature.
So to summarize, when an electron loses energy by passing a resistance, the energy is absorbed by the atoms, resulting in a higher temperature.
Now, what is going to result in more heat transfer? More voltage, or more amperage?
To answer this question, we can think of the atom arrangements in the wire as a series of energy toll booths. At each toll booth along the road, the electron must pay some energy in order to get past. This happens regardless of how much energy the electron has (voltage). So, lets use some completely crazy numbers to explain this.
Imagine a wire with five energy toll booths, each toll booth has an energy fee of one joule. One electron with ten joules of energy passes through this series of toll booths. At the end of its passage it will have paid five joules of energy. Now imagine five electrons passing through the same series of toll booths, each electron will have to pay five joules to get through. So five electrons, each paying five joules, will result in a total payment of twenty five joules of energy.
Thus, amperage (the number of electrons passing per second) is far more important than the voltage (the amount of energy each electron has) with regards to how much energy is transferred to a coil.
So why do we adjust voltage on VV devices, and get a different vape experience? This is due to Ohms law.
- Ohms Law
Unfortunately the reason for this law is quantum mechanical and is thus very complicated, so for the purposes of this guide it would be impractical to try and explain it.
The law can be expressed in various, equally valid mathematical statements:
Voltage = Amperage * Resistance or V = I*R
Amperage = Voltage / Resistance or I = V/R
Resistance = Voltage / Amperage or R = V/I
The official (if there even is one) statement of ohms law is that the current through a conductor is directly proportional to the voltage across the conductor, where the constant of proportionality between the two is the resistance.
This has a couple of implications that are important to vapers:
- With a constant resistance, if you increase the voltage across your coil, the amperage will also increase.
- If you maintain a constant voltage, and use a lower resistance coil, the amperage will increase.
Usually when this law is used by vapers, it is used to calculate amperage, in order to ensure that the build used is safe for the battery.
To give some examples:
a) Your battery is rated at 10 amps max output and you build a 1.2 ohm coil. On a full charge most batteries output 4.2 volts.
Amperage = Voltage / Resistance
Amperage = 4.2 volts / 1.2 ohms
Amperage = 3.5 amps
Since the 3.5 amps required by the build is less than the 10 amp maximum of the battery, this would be a safe build to use.
b) Now say you again have a battery rated at 10 amps max output, but this time you build a 0.4 ohm coil.
Amperage = Voltage / Resistance
Amperage = 4.2 volts / 0.4 ohms
Amperage = 10.5 amps
Now the build will draw 10.5 amps and the battery is only rated for 10 amps, this would be a dangerous build.
There are various ohms law calculators you can use if you are scared of messing up the maths. On both android and apple devices you can simply search ohms law calculator on the app store.
On a pc you can use Ohm's Law Calculator
On most of these apps you could just plug in the voltage (almost always 4.2) and the resistance of your coil. Hit the calculate button and the results will pop up.
4.0 Power
Power, measured in watts, is a description of how much energy a particular flow of electrons can deliver. It is a combination of voltage and amperage. Mathematically the relationship is described as:
Power = Amperage * Voltage or P = I * V
Examples:
a) A coil draws 2 amps from a mech mod battery (4.2 volts max).
I * V = P
2 amps * 4.2 volts = 8.4 watts
b) A coil draws 4 amps from a variable voltage device set at 3.8 volts
I * V = P
4 amps * 3.8 volts = 15.2 watts
The above formula can be substituted into ohms law to yield two further useful formulas:
Power = Voltage2 / Resistance or P = V2 / R
Power = Amperage2 * Resistance or P = I2 * R
The most commonly used power formula for vapers is the one relating power, voltage and resistance. This is because it is very easy to tell what voltage a battery is supplying.
Examples:
a) A battery in a mech mod (4.2 volts max) is connected to a 0.8 ohm coil.
P = V2 / R
P = 4.22 / 0.8
P = 22.05 watts
b) A variable voltage device is set to 3.6 volts and is connected to a 1.2 ohm coil.
P = V2 / R
P = 3.62 / 1.2
P = 10.80 watts
And this ends the theory portion of this guide.
I hope this all made sense, if you have any questions please feel free to leave a question and either myself or another knowledgeable person will be sure to respond.
Happy vaping!
