As far as I know, all VV regulators, whether buck (step-down) or boost, use a similar method of voltage adjustment: a variable resistor, called a potentiometer. This may be implemented mechanically by a rotating circular dial that is turned by fingers (as in Kens VV boxes), thumb (as in the Buzz Pro and Infinity Pro), jewelers screwdriver (as in madvapes VV boxes, original Buzz, etc.), or implemented electrically by pushing buttons (as in the ProVari, Darwin, and LavaTube) for a precise and discrete incremental increase/decrease in voltage.
The advantage of an electrical pot with a built-in voltage display is precision. You get the same increase or decrease with every button push. The disadvantage of this method is that it may require many button pushes to get the voltage where you want it. For some vapers, this is fine. For others, it can be a major pain in the you-know-what. Some folks dont like having to push an electrical button switch 20 times to move the voltage up or down by 2 volts.
Different but equally obvious problems plague mechanical pots with rotating dials. One problem is the lack of precise certainty. Many of these variable resistors are wildly non-linear. This means that if the dial has a total turn arc (from lowest voltage to highest) of 180°, or half a turn of the dial, the increments of voltage adjustment within that arc are not even. If the lowest setting is 3.3V and the highest 6.5V (this varies depending on the regulator chip used), then the voltage change over the entire arc of dial turning is 3.2V. So, 3.2V over 180° of turn should mean that 30% turn of the dial alters the voltage by about .5V. Unfortunately, that is often not the case.
In some VV mods that use dials, turning the dial from lowest to middle adds only a single volt, but then the next 30° of turn shoots the voltage up by two more volts. If the sweet spot you want is in that very compressed area, hitting the target voltage can be very difficult.
First off, extreme non-linearity of the dials adjustment range means that you really cant get to your desired voltage by feel or by eye. No, youll need to hook up a voltage display at the atty connection, by using either a standard VOM with leads (which is dreadfully awkward and can even short out the connector) or an LED digital voltage display (which must be screwed onto the connector, but wont work at all with pulsed regulators).
Even with the addition of an external voltage display, sometimes the throw on that compressed section of the dial is so small that a tiny increment of turn causes overshoot of the desired voltage, meaning that it takes multiple adjustments of the dial back and forth to actually hit the voltage you want.
Lets say you want a setting of 4.6V unloaded. With a non-linear dial, you may sit there with your jewelers screwdriver and external voltage display and miss your target again and again. You start at 4.2V and turn the screwdriver a tiny bit, but the voltage jumps to 5.1V. You then turn the screwdriver ever-so-slightly back in the opposite direction, but the voltage collapses down to 3.9V. Just as some people dont like pushing a switch 20 times to reach their desired voltage, non-linear dials force us to micro-adjust with the screwdriver or fingers that same 20 times back and forth. This is barbaric, not to mention frustrating.
With my Madvapes VV boxes, Ive gotten pretty fast with the whole process. I can usually set the voltage exactly where I want it within about 30 seconds from beginning to end: screw on the LED display, set the voltage with the screwdriver, unscrew the LED, screw on the atty/carto/tank, and vape. Half a minute for the whole procedure, but I would still like it to be quicker and easier.
How easy and accurate is the Buzz Pro? The thumb-adusted dial (called the "hit control" by NotCigs), with its green, yellow, and red paint marks, is the most linear, stable, and predictable dial Ive used. First of all, the wheel turns very smoothly, with the perfect resistance to being rotated (so that it won't change settings on its own or by your hand brushing against the dial). That's terrific.
With the yellow mark lined up with the white reference mark in the center of the "window," my Buzz Pro is always at 4.4V unloaded. Same with the others markers---red is always 5.2V, while green is always 3.4V. Halfway between green and yellow is always 3.8V, meaning perfectly linear, which is good news.
The bad news, however, is that the least linear section of the wheel is just after the yellow mark. To be correctly linear, the halfway point between the yellow and red paint marks should read 4.8V. Unfortunately, this is where my particular Buzz falls far short. A tiny movement of the dial past yellow moves up the voltage to 5V way too quickly (at only a quarter of the arc between the yellow and red paint marks, so that hitting increments of voltage accurately between 4.5 and 5.0V (which is right in the area of my sweet spots) is quite difficult, and nearly impossible to achieve by eye-balling the dial.
If the dial were truly linear all through its rotation arc, Id give the Buzz Pro a perfect score and A rating as a brilliant VV. As it is, with the non-linear distortion from 4.4V to 5V, I have to knock down the grade to a B. It is, however, my current favorite VV (and I own 13 of them).
The advantage of an electrical pot with a built-in voltage display is precision. You get the same increase or decrease with every button push. The disadvantage of this method is that it may require many button pushes to get the voltage where you want it. For some vapers, this is fine. For others, it can be a major pain in the you-know-what. Some folks dont like having to push an electrical button switch 20 times to move the voltage up or down by 2 volts.
Different but equally obvious problems plague mechanical pots with rotating dials. One problem is the lack of precise certainty. Many of these variable resistors are wildly non-linear. This means that if the dial has a total turn arc (from lowest voltage to highest) of 180°, or half a turn of the dial, the increments of voltage adjustment within that arc are not even. If the lowest setting is 3.3V and the highest 6.5V (this varies depending on the regulator chip used), then the voltage change over the entire arc of dial turning is 3.2V. So, 3.2V over 180° of turn should mean that 30% turn of the dial alters the voltage by about .5V. Unfortunately, that is often not the case.
In some VV mods that use dials, turning the dial from lowest to middle adds only a single volt, but then the next 30° of turn shoots the voltage up by two more volts. If the sweet spot you want is in that very compressed area, hitting the target voltage can be very difficult.
First off, extreme non-linearity of the dials adjustment range means that you really cant get to your desired voltage by feel or by eye. No, youll need to hook up a voltage display at the atty connection, by using either a standard VOM with leads (which is dreadfully awkward and can even short out the connector) or an LED digital voltage display (which must be screwed onto the connector, but wont work at all with pulsed regulators).
Even with the addition of an external voltage display, sometimes the throw on that compressed section of the dial is so small that a tiny increment of turn causes overshoot of the desired voltage, meaning that it takes multiple adjustments of the dial back and forth to actually hit the voltage you want.
Lets say you want a setting of 4.6V unloaded. With a non-linear dial, you may sit there with your jewelers screwdriver and external voltage display and miss your target again and again. You start at 4.2V and turn the screwdriver a tiny bit, but the voltage jumps to 5.1V. You then turn the screwdriver ever-so-slightly back in the opposite direction, but the voltage collapses down to 3.9V. Just as some people dont like pushing a switch 20 times to reach their desired voltage, non-linear dials force us to micro-adjust with the screwdriver or fingers that same 20 times back and forth. This is barbaric, not to mention frustrating.
With my Madvapes VV boxes, Ive gotten pretty fast with the whole process. I can usually set the voltage exactly where I want it within about 30 seconds from beginning to end: screw on the LED display, set the voltage with the screwdriver, unscrew the LED, screw on the atty/carto/tank, and vape. Half a minute for the whole procedure, but I would still like it to be quicker and easier.
How easy and accurate is the Buzz Pro? The thumb-adusted dial (called the "hit control" by NotCigs), with its green, yellow, and red paint marks, is the most linear, stable, and predictable dial Ive used. First of all, the wheel turns very smoothly, with the perfect resistance to being rotated (so that it won't change settings on its own or by your hand brushing against the dial). That's terrific.
With the yellow mark lined up with the white reference mark in the center of the "window," my Buzz Pro is always at 4.4V unloaded. Same with the others markers---red is always 5.2V, while green is always 3.4V. Halfway between green and yellow is always 3.8V, meaning perfectly linear, which is good news.
The bad news, however, is that the least linear section of the wheel is just after the yellow mark. To be correctly linear, the halfway point between the yellow and red paint marks should read 4.8V. Unfortunately, this is where my particular Buzz falls far short. A tiny movement of the dial past yellow moves up the voltage to 5V way too quickly (at only a quarter of the arc between the yellow and red paint marks, so that hitting increments of voltage accurately between 4.5 and 5.0V (which is right in the area of my sweet spots) is quite difficult, and nearly impossible to achieve by eye-balling the dial.
If the dial were truly linear all through its rotation arc, Id give the Buzz Pro a perfect score and A rating as a brilliant VV. As it is, with the non-linear distortion from 4.4V to 5V, I have to knock down the grade to a B. It is, however, my current favorite VV (and I own 13 of them).
