I was going through my old vape stuff the other day, sorting it to see what I could sell, when I came across my old iTaste SVD. I've pretty much moved to mechanicals at this point, but I decided to throw a coil in a kayfun and run it on the SVD one more time for nostalgia value. That SVD was my mainstay for a long time.
When I went to plan the build, and applied what I've learned about coil building since I gave up the SVD for mechs, it occurred to me that I might have been building the coils wrong on the SVD all that time. I was building coils in Aerotanks and Kayfuns at around the 1.5-1.3 range, thinking that lower resistance would create more heat, as it would with a mech. However, I think I might actually have been limiting my SVD's output. I could be wrong here, so check my logic:
With a mech, lower resistance = more watts for the given voltage = more heat. This is because battery voltage is a constant, sort of - it decreases as the battery dies, but every time you hit the mech's fire button, the battery's giving you whatever it was designed to put out. Your atomizer resistance is the controllable variable. APVs, however, have a range of voltage and wattage outputs. For example:
iTaste SVD
Voltage range: 3V-6V
Wattage range: 3W-15W
Now, let's say you put a 1.5 ohm atty on the SVD in variable wattage mode. You'll be able to get the full 15 watts of power to the coil, because in order to get 15W on a 1.5 ohm coil, you only need 4.74ish volts, which is well below the SVD's 6 volt limit. However, if you switch over to variable voltage mode and crank it up all the way to 6, then it's still only going to push 4.74ish volts to the coil - because if it did push more, it would be pushing more than 15 watts to the coil, and 15 watts is over the circuitry's limit. Too low resistance = a loss of potential voltage range.
The same thing happens in reverse if you use a resistance that's too high. For example, put a 3 ohm atty on there, and you'll never reach 15 watts - at the SVD's max 6 volts, you'll only be able to push the coil at 12 watts. Doesn't matter the mode you're in - voltage mode only goes up to 6 volts, and in wattage mode you can set it to 15, but the device will only be pushing 12.
In order to get the full range of voltage and wattage on the SVD, I have to build my coils to 2.4 ohms, because it takes 6 volts to push a 2.4 ohm coil to 15 watts - the most the SVD can handle in either volts or watts.
As I said before, with mechs the controllable variable is atty resistance and battery voltage is the constant. With APVs, the battery voltage is the variable - so the atty resistance should be a constant, unless there is some other reason to run a different resistance coil. I would assume a 1.5 ohm coil and a 2.4 ohm coil of the same gauge wire, run at the same wattage will result in the same heat?
I guess the point of all this is, why isn't it common knowledge to build coil resistance on an APV to match it's full output range?
Or is it, and I just missed it?
When I went to plan the build, and applied what I've learned about coil building since I gave up the SVD for mechs, it occurred to me that I might have been building the coils wrong on the SVD all that time. I was building coils in Aerotanks and Kayfuns at around the 1.5-1.3 range, thinking that lower resistance would create more heat, as it would with a mech. However, I think I might actually have been limiting my SVD's output. I could be wrong here, so check my logic:
With a mech, lower resistance = more watts for the given voltage = more heat. This is because battery voltage is a constant, sort of - it decreases as the battery dies, but every time you hit the mech's fire button, the battery's giving you whatever it was designed to put out. Your atomizer resistance is the controllable variable. APVs, however, have a range of voltage and wattage outputs. For example:
iTaste SVD
Voltage range: 3V-6V
Wattage range: 3W-15W
Now, let's say you put a 1.5 ohm atty on the SVD in variable wattage mode. You'll be able to get the full 15 watts of power to the coil, because in order to get 15W on a 1.5 ohm coil, you only need 4.74ish volts, which is well below the SVD's 6 volt limit. However, if you switch over to variable voltage mode and crank it up all the way to 6, then it's still only going to push 4.74ish volts to the coil - because if it did push more, it would be pushing more than 15 watts to the coil, and 15 watts is over the circuitry's limit. Too low resistance = a loss of potential voltage range.
The same thing happens in reverse if you use a resistance that's too high. For example, put a 3 ohm atty on there, and you'll never reach 15 watts - at the SVD's max 6 volts, you'll only be able to push the coil at 12 watts. Doesn't matter the mode you're in - voltage mode only goes up to 6 volts, and in wattage mode you can set it to 15, but the device will only be pushing 12.
In order to get the full range of voltage and wattage on the SVD, I have to build my coils to 2.4 ohms, because it takes 6 volts to push a 2.4 ohm coil to 15 watts - the most the SVD can handle in either volts or watts.
As I said before, with mechs the controllable variable is atty resistance and battery voltage is the constant. With APVs, the battery voltage is the variable - so the atty resistance should be a constant, unless there is some other reason to run a different resistance coil. I would assume a 1.5 ohm coil and a 2.4 ohm coil of the same gauge wire, run at the same wattage will result in the same heat?
I guess the point of all this is, why isn't it common knowledge to build coil resistance on an APV to match it's full output range?
Or is it, and I just missed it?
