miatafrank Posted May 23, 2010 Share Posted May 23, 2010 It's time for electronics 101, and how it applies to PVs. Current flow (measured in amps) is the movement of electrons through a conductor. These electrons are sent out by the power source (volts) to act as the workers, and resistance (measured in ohms) is in the path of current flow and will slow the electrons (workers) down. Power (measured in watts) is the measurement of work being performed in the circuit, and will always manifest itself in the form of heat (doesn't that sound like heating up an atomizer to you?). Of course too much heat (power/watts) will pop the atty. Now for the math, and I promise it's not that complicated: A physicist by the name of George Simon Ohm discovered that there is a tight relationship between voltage, current, and resistance. This relationship can be described and predicted by mathematics, which has become known as "Ohm's Law". The basic statement of this relationship is that voltage and current are directly proportional (when we increase voltage, current will increase as well), and that current and resistance are inversely proportional (when we increase resistance, current will decrease). Voltage = current multiplied by resistance Current = voltage divided by resistance Resistance = voltage divided by current Power = voltage multiplied by current Now let's apply Ohm's Law to a PV: A 3.7v device with a standard atty; Voltage 3.7v divided by an atty that is 3ohms = 1.23amps The heat produced by this is determined by the power in watts which is 3.7v multiplied by 1.23amps = 4.563watts We know this works, and we can use these numbers to compare the performance of the other combinations. A 3.7v device with a LR atty; 3.7v / 1.5ohms = 2.46amps 3.7v * 2.46amps = 9.126watts (remember, this is the heat) A 5v device with a standard atty; 5v / 3ohms = 1.66amps 5v * 1.66amps = 8.33watts (remember, this is the heat) A 5v device with a LR atty; 5v / 1.5ohms = 3.33amps 5v * 3.33amps = 16.66watts (remember, this is the heat.....POP) A 6v device with a standard atty; 6v / 3ohms = 2amps 6v * 2amps = 12watts (remember, this is the heat...on the bourder of POP) A 6v device with a HV atty; 6v / 4.3ohms = 1.395amps 6v * 1.395amps = 8.372watts (remember, this is the heat....is this really any better than a standard atty at 5v?) My ohm values for the attys are approximate, but you get the picture. This really answers all the questions "will this work with this?", "will that work with that?". I also think that anyone dabbling in making their own mods should understand these basics when choosing components that will work well together, and avoid injury. Jeffb, Uma, lazymorulz and 5 others 8 Link to comment Share on other sites More sharing options...
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