VV/VW General Discussion/Observations of a geek.

[Confuzzled1969]

I has a confused. When you say the battery is reading 3.8 volts do you mean the battery charge?

....and to answer your question, most all APVs use something called pulse width modulation (PWM) to regulate the voltage. It's not really AC as the electrons are only moving in one direction.If you Google it, you should find an explanation as to how this works.

It's a pulsed signal yes, but still it's only going in one direction, so it's not alternating current. It never crosses 0.

Well, technically speaking, any variance in peak voltage is going to behave as AC in a circuit.

The components in the circuit don't care if the baseline is 0 or not. You can have an AC signal that is alternating between 1000 volts and 100 volts, it may not be what is traditionally thought of as AC, but it is alternating, it just doesn't go negative. It is the rising and falling magnetic field that matters, not the polarity.

And you can have AC that rests entirly above the 0 volt baseline that most folks are accustomed to, but that doesn't mean it isn't AC. A square wave is still AC, it just isn't a sine wave. The curent is still alternating, it is just alternating between two positive states instead of positive and negative. And of-course it can be alternating between two two negative states and have the same characteristics as well.

 

[roosterado]

My Seigeli 20 and 30watt Do not. I have watched several Phil B Regulated Mod reviews where he shows devices that do not Buck Down also a minus to Him-and Me sometimes. Best to build coils on a non Bucking regulated Mod with high enough resistance that its not an issue IMO

 

[Ed_C]

I'm not an expert or EE, but everything I've ever read says that AC is bi-directional and usually sinusoidal.

 

[Confuzzled1969]

I has a confused. When you say the battery is reading 3.8 volts do you mean the battery charge?

....and to answer your question, most all APVs use something called pulse width modulation (PWM) to regulate the voltage. It's not really AC as the electrons are only moving in one direction.If you Google it, you should find an explanation as to how this works.

I'm not an expert or EE, but everything I've ever read says that AC is bi-directional and usually sinusoidal.

That is "usually" true, but also irrelevant when looking at circuit behavior. A falling magnetic field is a falling magnetic field, regardless of the potential. You may not be an EE, but think about it. Capcitors and inductors react based upon a rising and falling magnetic field, they do not react to voltage or the number of electrons flowing, those things are the limits of the physical parts, the real magic happens as a result of the magnetic field.

That is how engineers manipulate things into doing what they want, the end result is the physical characteristics of the device, but the design is based upon the job at hand. The physical characteristics are merely a result of what is required to reach the end result.

AC is an acronym for alternating current, a manmade definition that "usually" means something according to us. In the world of physics, our definitons are irrelevant, the characteristics of the device determines the result, not our definitions.

Ok, I apologize, that was a tad bit out there, but true none the less...

 

[AndriaD]

What you are seeing the charge left in the battery. It comes off the charger ≈ 4.2v and goes down as the power is depleted.

But you've got a 1.8Ω coil and have set the watts at 12 - to get 12w you need ≈ 4.65 volts. How can it do that? That's what a Boost circuit does. It's boosted the power up to where you have set it and it will stay there until it can no longer reach that level, when it will blink to be charged.

Similarly, if you put a fresh 4.2v battery into a device with a 1.8Ω coil and set it for 7 watts, it will buck the voltage down to around 3.6 to produce the wattage you set it for.

Re: amps

4.65 x 4.65 /1.8 = 12.0

12/4.65 = 2.58

4.65/1.8 = 2.58

√12/1.8 (6.66) = 2.58

I'm so glad I have so many vw devices. All that math makes my eyes cross and my head hurt, and a square root sign just looks like a check mark. Viva variable wattage!!

The Math Anti-Geek (i.e., math doofus)
Andria

 

[Confuzzled1969]

I has a confused. When you say the battery is reading 3.8 volts do you mean the battery charge?

....and to answer your question, most all APVs use something called pulse width modulation (PWM) to regulate the voltage. It's not really AC as the electrons are only moving in one direction.If you Google it, you should find an explanation as to how this works.

I'm so glad I have so many vw devices. All that math makes my eyes cross and my head hurt, and a square root sign just looks like a check mark. Viva variable wattage!!

The Math Anti-Geek (i.e., math doofus)
Andria

That's OK AndriaD, none of us do math anymore, we all sit behind a key board and the machines do the math, they're better at it anyway...

 

[The Ocelot]

I'm so glad I have so many vw devices. All that math makes my eyes cross and my head hurt, and a square root sign just looks like a check mark. Viva variable wattage!!

The Math Anti-Geek (i.e., math doofus)
Andria

It is a check sign, I can't find a square root symbol on my computer.