Kibbles & Bytes Blog

In my last segment in Kibbles and Bytes I did my best to cram in as much introductory information as I could about alternating current. I talked about the difference between AC and DC and why we use AC at the electricity grid level. For the most part though I didn’t get into some of the finer details about AC, other than that it’s current that alternates and this makes it very easy to transform the voltage of AC power.

One of the most difficult things to wrap your head around when it comes to AC is the fact that at any given time, the voltage is different. If you charted AC voltage on a graph with time on the x-axis, you’d see a sine wave.

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All waves have some general properties such as amplitude, frequency and phase. Amplitude and frequency you’re probably familiar with already from radio, and in the case of AC they mean the same thing. In the US, the frequency of AC power is 60Hz. This means that it cycles up and down 60 times every second. In other countries around the world the frequency is 50Hz. Actually, only North America, large parts of South America, Saudi Arabia, the southern part of Japan, North and South Korea and Taiwan use 60Hz. Generally speaking, the frequency of the AC power won’t negatively affect electronics as long as the voltage is the same. Most of the areas that use 50Hz also use voltages in the 220-240 range though. Sometimes the 60Hz frequency is used to drive clocks in electronics, though with digital circuitry, this is less common today. So if you had a piece of equipment with a clock that was driven by 60Hz AC, using 50Hz AC would prevent the clock from being accurate.

Amplitude of AC is where things become a little less straightforward. In North America, standard household power is 120VAC. You might think this means that the AC signal oscillates between +120VAC and -120VAC, but this is not the case. Actually, a 120VAC signal will oscillate between +169.7VAC and -169.7VAC. Why do we call it 120VAC power then? Well, think about the AC wave. At any given time its value is different. When describing the power, what value should you use? 169.7? Why not 40, or even 0? As you can see, choosing any voltage on the AC waveform would be arbitrary and not representative of the power being delivered. 120VAC is the RMS (“**root mean square**”:https://en.wikipedia.org/wiki/Root_mean_square) of the AC signal. The math behind this starts to get complicated, but at least in the context of electricity, the RMS of the AC signal is a representation of the average power delivered by that signal. In other words, the amount of power delivered by a 120VAC signal is equivalent to 120V of direct current.

Do you wish that was the end of the story? It’s not. When we talk about power delivered in this case, we have to talk about power delivered into a purely resistive load. This is because once again, AC is a sine wave. Now we arrive at the third property of a wave: its phase. The phase can be described as when the signal passes through 0 to go from negative to positive or positive to negative. In AC power, phase is very important because certain types of loads (capacitive or inductive) can shift the phase of components of the signal. Normally we would think about an AC signal as two things in one: voltage and current. The voltage goes up and the current goes up with it proportionally ??in phase??. This is not always the case however. Using inductive or capacitive loading, you can cause the phase of parts of the signal to shift so that, for example, the voltage leads the current by half a cycle.

Let’s try to round this out. In AC circuits, the concept of direct resistance doesn’t really apply the same way that it does in DC circuits. This is, again, because the voltage in AC is constantly changing. A changing current will create a changing magnetic field, and based on the properties of Lenz’s Law, a magnetic field will be proportional to the electrical current that created it, but it will be in direct opposition to it. In a way, it’s analogous to Newton’s third law of motion. These generated magnetic fields can provide a resistance to changing current via certain devices like inductors. This causes the current component of the signal to advance its phase ahead of the voltage component in the case of inductive loads and behind the voltage component in the case of capacitive loads. This “resistance” in AC circuits is called impedance and the combination of inductive and capacitive factors in a circuit forms the imaginary concept of reactance.

Don’t feel bad if all of this seems very confusing. When I took some electrical engineering classes in college (not my major, I took them for fun), they were the only classes I really struggled with. I’ve actually learned more and understood things better by watching “**videos on YouTube**”:https://www.youtube.com/user/jeriellsworth/ and reading “**books**”:http://www.wiley.com/WileyCDA/WileyTitle/productCd-0764542001.html. I also learned a lot in designing and assembling my photovoltaic power station. I think anybody can learn this stuff, and it’s very rewarding when you do.

I was fortunate enough to get my hands on and receive the new iPhone 7 Plus on release day. I skipped the iPhone 6s when it came around so when the 7 was announced I jumped at the chance to upgrade and I haven’t regretted it once. Despite the suggestions from my co-workers I’ve yet to drop my phone into a glass of water…perhaps that review will come in a future issue. For now, I’ll still be playing it a bit safe!

Like many of you, I’ve read some of the reviews out there and some reviewers are less than impressed with the phone, especially the camera. Coming from an iPhone 6, and after a few blunders with my first few photos, I can say it’s clear that there are significant improvements in the quality of the photos. I am not a professional photographer by any means but I enjoy taking photos and I take a lot of them. For the first few photos that I took with the phone it appeared that the phone was struggling to focus on the object I was trying to take a photo of. Once the camera focused, there hasn’t been a single hiccup with my photos, but briefly, I did wondered if I’d gotten a defective phone. This past weekend I took my phone to the local fair and became truly impressed with the camera. In showing the photos to friends and co-workers we can clearly see the difference in the quality. I’m most impressed with the fact that it seems no matter the lighting, the pictures come out clear and crisp. Inside, outside, the photos are just as great. My biggest surprise has been that I’ve had little need to use my flash, even when taking nighttime photos.

I’ve noticed a significant increase in speed with with 7, especially with the fingerprint recognition. The speed is so fast when I put my thumb on my phone I actually thought I forgot to set the passcode protection. There is almost no delay when I go to unlock my phone and I’m instantly at my home screen. The larger screen of the plus now also means that I can utilize landscape mode in multiple applications. This isn’t new to the 7 but is a feature of the plus that I’ve been missing out on! I love that I can look at my e-mail in landscape and easily toggle through my inbox. The dual speakers have also made for a much clearer listening experience. Don’t get me wrong, it’s not the same experience as with the iPad Pro but it’s a significant improvement.

Lastly I’ve not missed the lack of of a headphone jack. Early rumors and reports had me wondering, but with most speakers systems and headphones running wirelessly it’s far less of a obstacle than originally feared.

Have you upgraded to Mac OS X Sierra yet? I know that some people wait awhile to upgrade but I have been running Sierra for some time and you will want to upgrade. It is a rock-solid upgrade, it is free and it brings a lot of new features to the Mac. In the words of one big loser, “what do you have to lose?”

Okay, political commentary aside, one of the most exciting and useful features of Sierra is that Siri, finally, has come to the Mac! You know I have been playing around with Amazon’s Echo and I can definitively tell you that Siri is way smarter than Alexa. I still like Alexa but she pretty much is good for telling me dog and pirate jokes.

You can access Siri by clicking on the menu bar icon in the upper right-hand corner of your Mac’s screen or by clicking on the Siri icon in the dock. If you do not see those, you might not have Siri activated so go to System Preferences > Siri and check the box to “Enable Siri”. There you will find the check box to “show Siri in menu bar” which you can toggle on and off as well as options to choose Siri’s language and voice. You can also choose a keyboard shortcut if you would like, F7 is the default.

But, don’t you want to just say “Hey Siri”? That doesn’t necessarily work out of the box but you can make it work! Make sure you activate enhanced dictation in the keyboard system preference. Then, you can go to System Preferences > Accessibility > Dictation to set up the voice command that will activate Siri with a “Hey Siri”.

So, what can ask Siri to do for you? Well, start out by asking her what she can do. You will get a nice long list of things. You can ask Siri to launch apps, tell you the weather, get the Cubs score, FaceTme a friend, get directions to your meeting and so much more. I have been using Siri to find particular files, launch my apps and most of all to settle trivia bets.

Remember PDAs? Not public displays of affection, the other PDA – Personal Desktop Assistant. Well, Siri finally has made that a reality on your Mac. Use Siri to manage your calendar, remind you of appointments or bills to pay, play music for you or just a huge range of tasks. Here’s one “huge list”:http://osxdaily.com/2013/02/05/list-siri-commands/ of Siri commands.

One of my favorites is searching mail. I can say “find me emails from Hapy” and Siri will give me those almost instantly. Better yet, I can ask Siri to email someone about that Kibbles & Bytes special or set a calendar appointment for the meeting with my service team. I think you are going to like Siri on the Mac!

It is officially autumn and right on schedule we have some cooler weather in store for us here in the Green Mountains. More and more colors are appearing on the hillsides as we enter fall foliage season. We are doing our annual Apples to iPods promotion with the Vermont Department of Tourism. They hide wooden apples in the various pick-your-own orchards which when found, can be traded for iPods and other prizes we supply to the state.

I got my new Apple Watch series 2 and so far, I am very pleased. Yes, it is almost totally waterproof, it is brighter (I had to turn the brightness down a bit) and definitely faster when launching apps. If you haven’t upgraded to Watch OS 3.0, I do recommend it for a number of reasons although my favorite is still the ability to unlock my Mac automatically when I am wearing my watch. I also, finally, got a shipping notice on my new iPhone 7+ so Emily won’t be able to flaunt hers any longer. I can’t wait to try out the new camera.

There were rumors this week about Apple buying some car companies including McLaren and Lit. Opposite ends of the spectrum but I’ll gladly drive either of those! I love my Chevy Volt, though, and have been averaging about 110 miles per gallon on the plug-in hybrid and like showing off CarPlay. I loved the self-driving cars in movies like “Minority Report”, “I, Robot” and with the comical android driver in “Total Recall.” With predictions of driverless taxis within 5-years, future shock is real.

This week’s “**Kibbles & Bytes exclusive**”:http://www.smalldog.com/wag900002392 is a Hammerhead charger bundle. This week, you can get two Hammerhead 2-port USB wall chargers and a Hammerhead 2-port automobile charger for only “**$24.99!**”:http://www.smalldog.com/wag900002392 That’s over half off the regular price. You can never have too many chargers and these can charge an iPhone and iPad simultaneously.

Lastly, I’d like to take a moment this week to bring up an important cause. Over the years I’ve had the pleasure of meeting so many wonderful individuals within our sales channel and Amanda Haddock is one of those people. Please consider supporting the “**Dragon Master Foundation**”:http://www.dragonmasterfoundation.org, a cause she along with her family are deeply rooted in and help fight brain cancer.