Don't forget about Watts Law
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Ok, please explain to me HOW the atty's coil has ANY bearing on altering or controlling the duty cycle
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Agreed, I think some maybe trying to explain how a wall heater works and not a PFM board .................
Ummmm.... my reply you quoted said nothing about duty cycle so I can't answer your question...
"You can use any resistance coil you want"
Not necessarily ? So anyone pushing the envelope of high power/low coil resistance can run into that.
Run into what ? how does the PWM controller know / care what coil you have on your atty ?
Couple ways this could happen...
1. Regulated mods have a limited voltage swing, both upper and lower range. If you have a very low resistance coil, and want to max out the power, the mod may not go low enough to get there. If you have a very high resistance coil, the mod may not be able to output enough voltage to get to max power.
2. Regulated mods have a maximum current they can handle, as well as maximum power. A very low resistance coil would require relatively very low voltage but very high power to get to max power. If you used a coil at or near the minimum resistance it is specified for, it might not get to max power.
The above is a little theoretical but there are a lot of mods out there, and many of them claim to handle ridiculously low resistance coils, as low as 0.1 ohm, and I see lots of threads from not very well educated vapers here asking about such ridiculously low resistance coils, like "how do I build a 0.1 ohm coil". And I shudder when I read that because I know how they are trying to push some envelopes but are clueless. So maybe not so theoretical.
Also not all mods even specify a max current output. And VW only mods often do not specify the voltage ranges they can handle. For example, my Evic-VTC Mini claims to go to 75W and handle 0.1 ohm coils. That requires 27.5A at 2.75V. I kind of question if it can go there, but I'm not going to be the one to stick a 0.1 ohm coil in there to find out
The minimum firing resistance of a regulated mod is there to protect the mod itself, too low of a resistance and there will be too high of current going through the board then it is designed to handle causing it to be damaged.
If you are responding to my post(s)... the minimum firing resistance is the minimum resistance that the mod should fire under any circumstances. Can we always assume that that minimum resistance will fire at any power level? Same for any maximum (or unusually high) resistance, specified or not. The Evic-VT, for example, actually specifies a lower max power output for the low end of it's allowable resistance range. Given the varying levels of build quality and documentation quality in the industry, I'm not sure you can assume too much here. But that is a personal opinion, YMMV.
My original point was only to suggest that those pushing the max power of their regulated mods and also pushing their coil designs ought to be familiar with Ohm's law and it's close derivations such as "Watt's Law" just in order to do a sanity check on what they are doing.
No sorry I was just referring to where this conversation has gone, and no the mod should safely be able to fire lower than the minimum resistance at lower wattages, they would set it based on the maximum power of the device, for example a mod designed to put out 150w and fire as low as .15 ohms can safely handle about 31 amps of current through it (or so they would claim, I wouldn't really trust that). It should also safely fire .1 ohms at 100 watts but since it could be turned up past that they limit it to .15 to ensure people don't over draw their devices.
Couple ways this could happen...
1. Regulated mods have a limited voltage swing, both upper and lower range. If you have a very low resistance coil, and want to max out the power, the mod may not go low enough to get there. If you have a very high resistance coil, the mod may not be able to output enough voltage to get to max power.
2. Regulated mods have a maximum current they can handle, as well as maximum power. A very low resistance coil would require relatively very low voltage but very high power to get to max power. If you used a coil at or near the minimum resistance it is specified for, it might not get to max power.
The above is a little theoretical but there are a lot of mods out there, and many of them claim to handle ridiculously low resistance coils, as low as 0.1 ohm, and I see lots of threads from not very well educated vapers here asking about such ridiculously low resistance coils, like "how do I build a 0.1 ohm coil". And I shudder when I read that because I know how they are trying to push some envelopes but are clueless. So maybe not so theoretical.
Also not all mods even specify a max current output. And VW only mods often do not specify the voltage ranges they can handle. For example, my Evic-VTC Mini claims to go to 75W and handle 0.1 ohm coils. That requires 27.5A at 2.75V. I kind of question if it can go there, but I'm not going to be the one to stick a 0.1 ohm coil in there to find out
Regulated mods (do not) have a limited voltage swing, they have whats called switching regulators which require a means to vary their output voltage in response to input and output voltage changes so you would need to incorporate a PWM or PFM that controls the input to the associated power switch, which controls its on and off time (duty cycle), nowhere in between or on any side for that matter, does the battery see the "atty's resistance".
What is of more importance is the size of the wire gauge used from the output of the PCB, that's were you will see major problems if they do happen.
There is no point in another 3 pages worth of your walls of text and me going "Please read what I initially wrote". I can't help if you opt for misinterpreting my words and taking grave offense.
I can't believe no one mentioned Amp's law. It's what keeps people from ...... on the third rail.
Do they belong to a clan?
Like, The Wu Tang Clan?
I only asked because I study Yang Style Tai Chi which also has a Sword Form:
I've taken classes with Master Yang Jun. But not for the Sword Form..
Maybe they are more like Wang Chung. (I used this video instead of Everybody Have Fun Tonight for fear it would give someone epileptic seizures.)
If it's Ok with you I will forget about "Watts Law" since in all my years of electrical engineering it's not a term I or my coworkers ever used, nor did any of my professors use the term. A watt is simply a unit of measure of power and it can apply to not just the rate of electrical energy consumed, the term can be used for the rate of mechanical energy consumed as well. After all the concept of watts and horsepower, both units of the measure of power, were made by James Watt, the inventor of the STEAM engine.
I simply refer to the measure of energy consumption as Power, and I use Power formulas to calculate how many watts of power.
Also these days "heat" is defined in thermodynamics as work and is not synonymous with "temperature". So 50 watts of heat being generated by two coils can be at different temperatures depending on the coils size (thickness and length), wicking, air flow, etc. as I believe some have stated already here. In common usage people do tend to use "heat" to mean the same thing as "hot"and "temperature", but in engineering and science they aren't.
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I agree with most of what you're saying, as far as you never using watts law, that is fine, in my career as an electrician it is something that has come up often both by professors and through textbooks, and a term I use on the job quite often. Your power formulas are my watts law, I'm not really sure how this thread turned so ugly, my entire point of starting it was more or less to say current draw on a battery is measured by P/E in a regulated mod and E/R in a mech mod, I've had so many people tell me they calculate how much current in their regulated mods by E/R because the guy at the vape shop told them they needed to use ohms law. That kind of vague information is what's leading to people having their batteries vent and explode and it's a huge pet peeve of mineIf it's Ok with you I will forget about "Watts Law" since in all my years of electrical engineering it's not a term I or my coworkers ever used, nor did any of my professors use the term. A watt is simply a unit of measure of power and it can apply to not just the rate of electrical energy consumed, the term can be used for the rate of mechanical energy consumed as well. After all the concept of watts and horsepower, both units of the measure of power, were made by James Watt, the inventor of the STEAM engine.
I simply refer to the measure of energy consumption as Power, and I use Power formulas to calculate how many watts of power.
Also these days "heat" is defined in thermodynamics as work and is not synonymous with "temperature". So 50 watts of heat being generated by two coils can be at different temperatures depending on the coils size (thickness and length), wicking, air flow, etc. as I believe some have stated already here.
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