Archive for June 20, 2013

Keeping In-Sync

Flicker, flicker, everywhere!

No I’m not referring to the regrettable boy band, nor am I going to even touch the “cloud” as it were. This is about something much more solid, more hardware.

I remember the early days of personal computing, which (for me) was the 1980s when we had the option of a spinach-green or nuclear-orange command-line interface, or, if you were lucky, one of the primitive 256 colour machines, all of which used an electron gun shot at your eye.

Back then, owning a “flicker screen” was essential. Although the monitors were capable of refreshing in sync with mains power (60Hz), sadly the computers of the day were not and you could get all sorts of eyeball-bleeding from looking at the flickering moire-patterned mess. Remember the signs they used to put on computers “Use no longer than 15 minutes”?

Last night, finding myself alone, I sat myself down to watch a movie and have a quiet evening. To watch movies, I use my media pc (an old Acer laptop with Ubuntu + XBMC) and I just love it. Such convenience at never having to fiddle with discs and control my entertainment experience. It was working fine, or so I thought.

As I start to watch the film, an art film with lovely scenery, I notice something amiss. Some nightmare born out of the 80s. Not a flicker, quite. I notice just a subtle distortion. A flickery horizontal line that starts at the bottom of the screen and slowly winds its way up to the top, only to begin again at the bottom. That just doesn’t cut it, does it?

Setting aside my initial fears that the aging laptop simply couldn’t handle high-definition footage as panic-y, I spelunk into the settings to find out a problem.

My 80s experience saved the day: it was the vertical refresh rate being out of sync with the TV’s. This meant that the computer was refreshing the screen at a different rate than the display, causing this horizontal artifact that would progress up the screen. Much like when you used to see a computer monitor filmed on television and see it vertically dance, but more subtle, more digital.

To set it back, I simply turned on the “vertical blank sync” and the problem was solved, smooth watching again.

In a strange coincidence, with refresh rates much on my mind, there was an article posted on Slashdot today concerning the flickering of LED displays. What was neat about it is that it appears some people actually notice the flicker coming off of the latest generation displays – even though the refresh rate was in sync and fast enough for a human not to care about or notice.

The type of “flicker” is a completely unrelated issue than the type we were used to from CRTs.  In order to “dim” an LED, those of you in electronics will know that you don’t simply reduce the power to the LED, you have to flash it very fast, and the frequency of that flashing gives you the apparent brightness.

Unlike lightbulbs or CRT displays, which run on alternating current,  LEDs must run on direct current. This means it is either ON or OFF not anywhere in-between. To achieve a dimming effect, you modulate the DC current in a square wave (on-off-on-off-on-off) and set the frequency (duty cycle) to achieve the desired apparent brightness. This is called “Pulse-Width Modulation” or PWM.

I, personally, have only noticed this in my own electronics projects (using a 555 timer and a LED) or on my jailbroken iPod Touch which allows me to set the brightness lower than factory. I have never noticed this on a flatpanel television or on the purdy display of my Macbook Pro.

None of this is particularly interesting of itself. Quite a dry subject actually :) . What made it interesting was the aforementioned Slashdot post. Apparently a small minority can “see” this PWM flicker, and it’s driving them nuts causing eyestrain and nausea and call on the industry to fix this.

At least two comments posted on this article assert “it’s all in your head” and put it in the same category as people who wear tin-foil hats who put microwaves in the same category as gamma radiation.

One person struck a middle ground and perhaps suggested that the 60Hz flickering of the ambient fluorescent lighting is causing an interference pattern with the display refresh or this PWM dimming.

The question is: can you see it flicker? does it bother you? would you pay more money for a monitor that doesn’t do this? does anyone care?

I’m all for no flicker, but I’m damned if I can see it. Get rid of those stupid fluorescent lights first. Those DO bother me.

The EVOD BCC

Most awesome clearo yet.

The Ecig industry has always been driven by this wonderful grassroots DIY innovation, which to me is part of its appeal. Even though they have been around for about ten years, there is this air of it being a very young hobby with plenty of room for new improvements.

When I started, like most, I bought the 510 starter kit. Like most, I found it a sad, leaky, unsatisfying shadow of the analogs I wished to rid myself of. The root of my dissatisfaction was the 510 atomizer and cartridge system. It didn’t hold enough, it wasted a lot of juice, and the atty’s quickly became clogged to the point where, you didn’t want to throw them out, but had no idea how rehabilitate them. So you either put up with a sucky vape, wasted tons of cash on new parts that quickly failed, or gave up entirely (as I did for one year).

Now, with more experience and more products on the market, I feel one particular product has finally hit the sweet spot of vaping. Now, realize this is merely my opinion, and there are as many opinions on what makes up a great vape as there are vapers. Still, I think many have agreed that the EVOD BCC from Kanger finally delivers on the promise of a consistently satisfying, hassle-free vape.

EVOD BCC Clearomizer

EVOD BCC Clearomizer

Pictured here, you can see its quite a simple device. I believe it is the fourth generation of its kind being a direct descendant of the T3 clearo but delivering a better vape (I wouldn’t know, I haven’t tried the T3). A bottom-coil clearomizer like many others.

It holds about 1.5mL of juice which I think is a nice compromise of size vs. capacity. It features an integrated mouthpiece and although some have said this is a negative feature, I find it quite comfortable especially since I can’t stand loose parts or having it fall off. Its width and height feel in perfect proportion to the eGo style batteries it’s designed for. It has two oval sight windows cut into the coloured tank covering which comes in a variety of colours. Refilling is a snap: just unscrew the base, squirt some juice in (minding not to get it down the centre post) and re-assemble. The construction is solid and the build quality good. It screws together easily with no excessive force, the threads are smooth, and the seals tight. In three months of use I have not had one single leak. Something I cannot say of 95% of the other vaping products I have tried.

The best feature of all is that when the coil is clogged or spent, instead of throwing the whole thing in the bin like other clearos, one simply replaces the coil (called a “head”) and resumes vaping. For the enviro-conscious this is a boon, since there is less plastic waste and in general less of a feeling like you are trashing something that is 90% functional but for the 10% that is broken rendering it useless. Its also for the thrifty-minded, for the cost of one EVOD, you can buy a packet of 5 replacement heads. Though I have yet to “blow” a head (burn out the coil) I find its useful life is about one month due to cloggage and burnt juice (if one is not careful of vaping voltage or dry burning it by accident).

Replacement of these heads is quite simple. Simply unscrew the base, unscrew the head from the base, screw in a new head and re-assemble. Back to vaping in seconds. No fiddly screwdrivers or flaky pressure-fit bits. Performs just like new.

I’ve been using phoenix-style RBA’s (rebuildable atomizers) for some months now at home after ditching the 510 atomizer for good. I love them. I love how a few cents worth of silica wick and kanthal wire, and a couple of minutes of wrapping a new coil, I can be back to vaping. Compare that to the cost of a new 510 atomizer! Even when I started to use clearos for convenience when I was out, I still had this distaste for the thought of throwing them out the day they go south.

A recent discovery, thanks to evelwmn on YouTube, showed me that it is possible to rebuild EVOD heads. Yes – even if your head is clogged or burned out, they can be rebuilt just like new with a bit of wick and wire. I was delighted, it’s even easier to rebuild the EVOD heads than to rebuild a phoenix RBA. Within 15 minutes, I had rebuilt five of my clogged heads and now have a perpetual supply – further reducing cost (down to a few cents per) as well as the amount I need to throw into the trash. I mean, apart from physical damage, or mangling a thread, I can’t imagine how these parts could wear out! Wick and wire are the only disposables. Watch her video for instructions. Anyone can do this.

They also seem particularly resistant to cloggage and gurgling, and I have to try hard to pull enough juice through with dry puffs before I get a gurgle. As a result, getting juice in one’s mouth is a thankfully rare occurrence. Likewise, its difficult to get juice to leak downwards into the battery well, significantly reducing the cleaning required.

If it does get a bit gunky, just rinse with hot water and keep on vaping. The occasional rinse for cleanliness and the odd replacing or rebuilding of a head covers all the maintenance. Gone are the days of blowing gunk into a tissue, getting juice all over your desk (or self), boiling, soaking, rinsing and dry-burning. No need for special screwdrivers, allen keys, tweezers, toothpicks, q-tips or complicated maintenance routines and schedules. Simply fill, vape, and get on with life.

So its leakproof, so its parts are replaceable and rebuildable, so its reasonably inexpensive. That’s all great, but how does it vape?

Excellently. I found that I can consistently produce great big plumes of tasty thick vapour all day, all night – perpetually. Its design, though simple, is quite effective at doing this reliably. The 1.8Ohm stock coil seems perfect for use with 3.7V eGo batteries. I use a variable voltage spinner myself and can dial it in to vaping perfection. The coils last a long time, I have yet to burn one out (only clogged them). The four air holes significantly reduce the possibility of the intake being clogged. Some have complained that this produces a rather airy draw, which I enjoy. For those who don’t, its simple to block up one or more of these air intakes with a drop of glue or a bit of toothpick.

In conclusion, this really is the best product I have found for a consistent, hassle free, easy to maintain vape. I currently own four of them (black, stainless, blue and green) and keep them in rotation with different flavours. I pack enough juice to last a weekend and I know they won’t quit on me.

Happy vaping!