Series. Parallel. Series-Parallel

      Here it is, what you have all been waiting for, my amazingly relevant, real-life electronics story.

Just recently I was over at my friends house and he was stringing Christmas lights in a fort that we made for his daughter when one half of the lights went out. Only one bulb was out. So why then did half of them turn off? What about the other half? What does this have to do with electronics? The answer, it has everything to do with electronics.

Series. Parallel. Series-parallel. These words describe how circuits are connected. After learning about Ohm’s Law and how voltage, current, and resistance interact, this is a great way to gain a deeper understanding in how current flows (Electron Flow that goes negative to positive. Don’t let all those textbooks fool you with conventional current that goes positive to negative. Spring that one on your teacher and watch them backtrack trying to explain why it’s like that.).

A series circuit has only one path to ground.

A series circuit has only one path for current to flow through. The current in a series circuit will remain the same throughout, while there will be voltage drops along each component. Therefor, the total resistance equals the resistances of all the resistors together or, R_t=R₁+R₂+R₃+… Think of a box, to complete a circuit it must follow the lines to get back to the beginning or starting point.

Imagine that the switch is another light. When the switch is closed, like it is right now, all the lights "light" up. When the switch is open, or in the up position, all the lights are off. 

Parallel circuit, similar to a ladder,
has multiple paths to ground.

On the other hand, a parallel circuit has more than one path for current to flow. The voltage across each path is the same in a parallel circuit while the current is reduced along each path. The math for a parallel circuit is slightly more complex, to find the total resistance you take the inverse of the all the resistor’s inverses added up. Inversely, it looks, and is, easier then it sounds. R_t=1/((1/R₁)+(1/R₂)+(1/R₃)+…). Simple. Right? Imagine a ladder where the current has many paths or rungs to take to complete the circuit.

Now to tie everything back together with the Christmas lights. When lights are placed in a series circuit, there is only one path for the current to travel down. When a singular light goes out, it acts like a switch, essentially breaking the path and not allowing the current to flow past it (Standing current) to the other lights. If one light does not get any current, then none of them do. A parallel circuit has multiple paths for current to travel down, so if a light were to go out, the current would still be able to flow through the other paths available and light the other bulbs.

Almost every mystery has been solved, save for one. Why did half of the strand go out when one bulb blew, and not the whole strand? Because it was a series-parallel strand of lights, there were two series strands attached to the same plug, meaning while one half is out, the other is still able to light up.

In a series-parallel circuit, if the light on the left was to go out, the two lights to the right would still be on because they still have a path to ground. If one of the lights on the right was out, both on lights on the right would be out because they are in series, while the light on the left would remain on.

...My mistake in "Player Piano" was my failure as a futurist. I did not foresee transistors, and so imagined that super computers would have to be huge, with bulky vacuum tubes taking up a lot of space. -Kurt Vonnegut in "Letters"

Voltage, Current, and Resistance

            I have an amazing story (okay, it’s not that amazing, but the story will help drive my point home) about a cardboard fort, a strand of lights, and a broken bulb. The story however involves details that will need some clarification first, so I am going to leave you on the edge of your seats till later in the week when I publish that one.

           

Electricity. That is the topic that needs to be addressed, and without any further ado, I present: Voltage, Current, and Resistance. My old electronics teacher hated water analogies, so I figure the best way to explain the flow of electrons is with a water analogy.

Pretend your thumb is at the end of the hose.

Imagine a hose. The valve is voltage, or the amount of pressure pushing the electrons, so the more you open the valve, the more pressure you get, or more voltage. The water is the current or the flow of electrons that is being pushed by the voltage, and when you put your thumb at the end of the hose to vary how much water comes out, your thumb becomes resistance.

Now that I got that out of my system lets look at each term individually:

·      Voltage- Voltage is the pressure in a circuit, or “Potential Difference” detailing the difference between the pressure and ground potential or 0 Volts. Voltage is measured in Volts and abbreviated with a V.

·      Current- Current is the number of electrons that flow past a certain point each second. Current is abbreviated with an I, but the measure of current is in Amperes and abbreviated with an A.

·      Resistance- Resistance as the name implies is the restriction to the flow of current in a circuit. Resistance is measured in Ohm’s and abbreviated with the symbol Ω.

When we combine those three aspects we get Ohm’s Law. Named after Georg Ohm, Ohm’s Law states that current flow is directly proportional to the voltage applied and inversely proportional to the resistance. WHAT? As resistance increases, current decreases, and as resistance decreases, current increases. From all those fancy words we get the equations: V=I*R, I=V/R, and R=V/I.

Now that I got through all that, you’re probably wondering when will I ever need to know this? Chances are unless your building circuits, fixing old electronics, matching loads with speakers in live sound settings, or you just like doing physics…never. However, It will allow me to tell in much greater detail why all your Christmas lights go out when its only one bulb that is bad.

A very simple depiction of Ohm's Law, V=I*R, I=V/R, and R=V/I.

...My mistake in "Player Piano" was my failure as a futurist. I did not foresee transistors, and so imagined that super computers would have to be huge, with bulky vacuum tubes taking up a lot of space. -Kurt Vonnegut in "Letters"

Catching The MIDI Virus...

            Out of all the inventions within the audio industry, second to maybe only the Digital Audio Workstation (DAW), MIDI has helped shaped the way music is created today. More people then ever are able to create music without knowing how to play an instrument because a couple of brilliant engineers decided they needed a way to connect their synthesizers to other manufacturer’s synthesizers.

            Largely due to two men in the early 80’s, Dave Smith and Chet Wood, we have a digital form of communication for our electronic devices. So what is MIDI? Is it music? Is it an Instrument? Is it easy to use? MIDI, to put it plainly, stands for Musical Instrument Digital Interface, and it is not music, nor does it transfer any sound files; what MIDI is, is a binary code that transfers from one device to another and can do anything from tell a synthesizer what notes were pressed, the velocity they were pressed at, duration, to just about any other performance function you tell it to do.

            MIDI was designed to be simple; it was designed to be modified in the future. When MIDI was first introduced the cable that carried the binary information had 5 pins on the connecter; however, only three pins were used. Why the extra two pins you might ask. Well, the creators, Smith and Wood had enough insight to know that their invention would most likely be modified in the future; hence the reason for the extra two pins.

About thirty years later, are the two extra pins used? Yes and no. Some manufacturers have used the two extra pins to send power to their MIDI devices to get rid of the need for a power cord. The only problem with this method is that some cable manufacturers don’t even run cabling for those two pins on their MIDI cables anymore because of how long they went functionless. So while there is no official or standard use, their forward thinking has benefited some companies.

Here is the real kicker about MIDI. When it was developed, Smith and Wood did not ask for licensing fees. Instead, they wanted their invention to be adopted and standardized as quickly as possible. Talk about good marketing; as Seth Godin put it, free ideas spread like viruses. And spread it did, within one year other synthesizer manufacturers were installing MIDI systems on their devices. Today, MIDI has spread beyond synthesizers to other audio electronic devices such as drum machines, interfaces, all the way to non-musical devices that can cue different visuals onstage such as lighting and video.

            In a world that is overrun with devices that will not communicate nicely (android to apple phones or mac to windows computers), two men gave away their invention so the world of music could have a common digital language. And what beautiful binary it is.

MIDI connector schematic.

...My mistake in "Player Piano" was my failure as a futurist. I did not foresee transistors, and so imagined that super computers would have to be huge, with bulky vacuum tubes taking up a lot of space. -Kurt Vonnegut in "Letters"

In This Digital Age, Hold On To Your Analog Identity.

If things sound better out of tune, I bet this sounds beautiful.

            As we move further into the digital age we still grasp onto older analog concepts and procedures; maybe it is to make the transition easier for the older or original generation, or maybe its because they are sound theories and concepts to begin with. As the old saying goes, “If something isn’t broke, then don’t fix it”. That saying no longer applies; instead if something is working properly, we need to find a better way to make it work “more” properly. Along the way we have lost our soul.

            A perfect example of the old, irrelevant ideas incorporated in today’s digital world would be Control Voltages (CV) in software instruments. New software synthesizers, arpeggiators, and sequencers have no need for anything related to CV, but yet there it is on multiple new plug-ins. Why? Because the concept of CV is easily explainable, and it became universal language when synthesizers first became popular in the 1960’s.

            Simply stated, Control Voltages are varying voltages that can be used to control a range of parameters from pitch to modulation controls such as rate and depth and so forth. The concept behind an old synthesizer keyboard is that each octave is broken up into a voltage range. When a key is pressed, it triggers a voltage within that specific range telling the oscillator what the pitch, or frequency, is that was selected. Different synthesizer manufacturers broke the voltages up differently (Volts per Octave/ Hertz per Volt), but the idea was the same.

            I had the pleasure to repair some of these early synthesizers and see first hand how various keyboard Control Voltages were set up, giving me a better understanding. It truly is amazing to see how some of the early keyboards worked. It is even more amazing to see how their concepts can live on long after they are no longer relevant. Even the “Analog” feature on many software instruments is a testament to how popular and sought after those early sounds are.

            In the digital age where close to perfection can be achieved, by turning that “Analog” knob we slowly detune ourselves; a reference to how vintage synthesizers needed to be tuned, and when they weren’t, they would drift slightly, creating a more dynamic, rich sound. So, why in our quest for perfection do we use old, irrelevant concepts, or “Analog” functions? Because we are not perfect, and sometimes, being out of tune just sounds better.

Basic signal flow for subtractive synthesizer with a keyboard.

...My mistake in "Player Piano" was my failure as a futurist. I did not foresee transistors, and so imagined that super computers would have to be huge, with bulky vacuum tubes taking up a lot of space. -Kurt Vonnegut in "Letters"

They Don’t Make Things Like They Used To...

            They don’t make things like they used to; or least I don’t think they do. We have all heard the stories of how our parents and grandparents didn’t go buy new electronics every two years or so; they were built to last and they had them for what they described as decades. When something broke, they fixed it. That does not always seem to be the case nowadays.

            I have an old cassette player that I found in the trash that works perfectly, and yet my audio interface that is barely two years old has a broken input. When my grandparents moved into my parent’s house when I was younger, they brought a record player that my mom used when she was little that just kept spinning and spinning. Then tell me why my Korg synthesizer that is 3 years old has problems with the 5-pin MIDI connections (No, really, tell me, because I tried updating the firmware and it’s still driving me crazy).

           

            The only answer I have is that they don’t make things like they used to. Electronics today are built to be cheap, and are built to quickly replace its predecessor that came out only a year prior. On top of that, most of the electronic components that are used today are so small that machines have to do the soldering, and people are only used for quality control.

           

            There was a certain ruggedness to old electronics. They were big, solid, and they could take a spill; good luck dropping your phone or computer today, chances are you will be buying a new one. Robert Moog, to prove the ruggedness of his early synthesizers, used to plug the synthesizers in, play a few notes, and then push them off the table onto the ground. Moog would go pick the synthesizer up, plug everything back in, and then continue to play like nothing ever happened. Customers loved that demonstration; not only was he demoing the products features, but the durability of it as well.

            Today, we don’t expect our electronics to survive the fall, we don’t expect them to survive longer then a few years, and even if they do survive we buy the new version because the old one is out of date and holds us back. Electronics failing is the nature of the beast, but it seems like the beast has a shorter lifespan and quicker temper these days. I guess that’s just the way it is. But does it need to be that way?

If we dust it off maybe it'll still work.

...My mistake in "Player Piano" was my failure as a futurist. I did not foresee transistors, and so imagined that super computers would have to be huge, with bulky vacuum tubes taking up a lot of space. -Kurt Vonnegut in "Letters"