This is part 2 of my look at the Wismec Reuleaux RX200S. To read part 1, look here:
Here is the 0.2Ω load consisting of five 1Ω power resistors. The wires are 18 AWG.
The wires could have been thicker, and the solder joints more solid, but the point here is to have a consistent resistance, not necessarily the lowest one possible.
In any case, I’m measuring the voltage at the atomizer deck, so the voltage drop in the wires is not going to affect these measurements.
And here is the entire test setup.
The RX200 is connected to the load. The oscilloscope is connected to the center pin, and grounded at one of the negative posts on the atomizer deck.
Oh look, there’s a heartbeat.
There is one pulse every 200ms. Each pulse is about 450mV.
A closer look at one of the pulses. They vary somewhat in duration and shape, but in general they look like this.
The duration of each pulse seems to be somewhere between 5 and 10 ms.
Ok, enough of that. Let’s get to the meat of the matter.
Firing the mod
The Wismec RX200S still reads the load as a resistance of 0.23Ω.
I will measure the mod at the following settings: 5W, 10W, 20W, 40W, 80W, 160W, 200W and 250W.
At 5W the mod displays a voltage of 1.07V. The scope agrees.
At 10W the mod displays a voltage of 1.52V. The scope agrees.
At 20W the mod displays a voltage of 2.14V. The scope agrees.
At 40W the mod displays a voltage of 3.03V. The scope displays 3.06V RMS. Close.
At 80W the mod displays a voltage of 4.29V. The scope says 4.42V RMS. Only 3% too high in voltage, but closer to 6% too high in power (85W).
At 160W the mod displays a voltage of 6.07V. The scope says 6.32V, which is 4% too high. Convert to power, and we get more than 8% too much, at 173.66W.
At 200W the mod displays a voltage of 6.78V. Oscilloscope RMS is 7.06V (still 4% too high). Power is 216.71W which is still at 8% too high.
At 250W the mod displays a voltage of 7.58V. The scope said 7.81V during the first test, and 7.95V during the second, when the batteries were slightly discharged.
At 7.95V the voltage is closer to 5% too high, and the power is 274.79W, which is almost 10% too high.
Ramp up time
Looking at the shape of the graph, it is obvious that the ramp up time gets longer with higher wattage settings.
From a quick glance at the screenshot, it may look awfully long at 250W. Still, it’s only 150 ms or so at its longest.
That is probably not something you would ever notice while vaping.
Zoom & Enhance
The signal does look a bit hairy. Here’s the knee, just as the mod reaches the full voltage at its 250W setting.
And here is a closer look at the flat part, at increasing zoom levels.
This digital “ripple” seems to have an amplitude of about 0.4V give or take, which is ~5% of the total voltage. The frequency looks like 150 kHz or so.
I doubt that anyone would be able to hear, feel or taste any of that.
The RMS voltage is on the high side
When firing at full blast, the mod says that it’s outputting 7.58V. At 0.23Ω that is 249.96W and 32.96A. Very close to the selected power setting.
The scope on the other hand, said that it was measuring 7.81V RMS. At 0.23Ω that is 265.2W and 33.96A on the first try.
On the second try, the scope measured 7.95V, which is 274.79W and 34.57A.
That is a little bit lower than the measurement from my multimeter (see part 1), but still quite a bit higher than what the mod claims on its display.
It looks like the Wismec Reuleaux RX200S is a decent quality mod. Some shortcuts have been taken, but nothing too atrocious.
The mod does not have battery balancing, which is inconvenient for those of us who prefer to charge via USB. However, provided that the mod monitors the individual cells, and stops charging/discharging when it detects that a cell has gone out of bounds, this is not a safety hazard.
It does seem to fire a bit hotter than it should, especially noticable at higher power settings. Some may see this as a boon, while fussy nitpickers like me may be slightly irked. At least it doesn’t fire cooler than it claims to.
I think I can set the max output current in the Mod Range calculator to 35A, at least for now. I have ordered another handful of 1Ω resistors, so that I can make a ~0.1Ω load. When they arrive, I will see if the mod will refuse to increase the power due to the resistance being too low.
Other than that, I’m not really sure what to say about this mod. What do you think? Did I do the measurements wrong? Is the discrepancy significant? Do you prefer a mod that fires hot, to a mod that is accurate? And just how accurate should we really expect our mods to be? Feel free to let me know what you think in the comments below.