Some Math, or Way Too Much Text

Okay, so I'm out of tech and need to start back in on this subject. I need to buy another Arduino because mine is buried in the set, but I can still write about some details that are important.

Let's say you've got a mess of LEDs and a request to make some things light up. You don't need any fancy effects, just static light in some practicals or mounted somewhere on your set. It's not as straightforward as connecting the LEDs to a battery or wall wart and calling it done. An LED is not a resistive load, like a light bulb. The current through an LED is determined by the resistive elements of the circuit, while the voltage drop across its terminals is constant (Anywhere from 1.7V up to 3.5V are common values, depending on the color and brightness of the LED). What this means is that wherever you're using an LED, you'll probably use what is known as a current limiting resistor. This resistor is how you select the current flowing through your LED.

You're likely at least passingly familiar with Ohm's law, that is: V = IR. This is probably the most basic electrical relationship, and one every electrician should know about. Voltage equals Current times Resistance. There's a load of resources out there on the web that will tell you more than you ever wanted to know, so I'll speak specifically to how we want to manipulate this equation to calculate the value of our current limiting resistors.

So you've got a boatload of these diffused LEDs, like the ones I used in the buildings for As You Like It last year. If you scroll down that page, you'll see the specifications, and these are important. The big numbers to be aware of are the Forward Voltage and Continuous Forward Current. The forward voltage is the value required to make the LED light up (yes, it will probably glow at a lower level, but the color will be wonky and it will be very dim) and the forward current is how much current the LED is capable of handling before bad things happen. You can vary the current to vary the brightness (there are several techniques to accomplish this, and we'll talk about it), but you'll always need to provide these particular LEDs with 3.4V.

So say you're building a little glowing hand-prop. You already have rechargeable AA batteries on hand, and some 4 cell battery holders, so that's how you'd like to power the LED going into this prop. You want it as bright as possible, so you'd like to calculate the value of current limiting resistor that will provide you the 350mA of current we're looking for. It's simple. Our 4 AA batteries, in series, will provide us 4.8V (many rechargeable types provide only 1.2 volts per battery, rather than 1.5). We subtract the forward voltage of the LED, 3.4V and we have 1.4V 'left over.' Plug that into Ohm's law, along with our forward current of 350mA (For the record, the equation is in Volts, Amps, and Ohms, meaning we'll plug in 0.35 for our current), then divide to isolate R, giving us a value of 4.

This is a good place to mention that resistors come in sort of goofy values(wonder why?), so instead of our ideal 4 ohm resistor, we'll find either a 3.9 or 4.3 value. Typically err on the side of more resistance.

So now we've got our LED, our batteries, and a resistor value. Next we should determine what power rating we need for the resistor. If you push too much current through a resistor, it'll get quite hot (that's exactly how your toaster or electric oven works), so we want to be sure we have some headroom. Power can be calculated with one of two easy equations, either P = VI [power equals voltage times current] or P = I^2 * R [power equals current squared times resistance]. Using either of these, we discover that the power dissipated in our resistor is 0.49W. Resistors commonly come in 1/8, 1/4, 1/2 and 1 watt packages, so we could probably go with a 1/2W unit and be okay. Typically I will increase the resistance value, lowering the current below the maximum continuous forward current, this allows me more headroom with my resistors, reduces heat output of the LEDs (which is not completely negligible with these higher-powered units, and becomes something to account for with very high power units) and probably makes them last longer (though that's hardly a concern.)

There also exist numerous web-based calculators for finding these values, only a google search away. They'll often even spit out the 'real' resistor value and power rating. That's no fun, though.

The last thing you need to know is that an LED could be hooked up two ways, but will only function in one orientation. Don't worry, if you hook it up backwards, you won't hurt anything, it just won't light up, turn it around and try again. The two legs of the LED are commonly referred to as the anode and the cathode, the former being the 'positive' side and the latter being the 'negative.' The two legs will be different lengths, the longer one is the anode. You can also identify which is which visually (and you'll find yourself doing this at some point, no question), as I've indicated in the following photos. I've drawn an arrow pointing at the cathode, in each case.

What this means is that you'll connect the positive terminal of your battery or battery pack to the anode, and the negative terminal the cathode, with the resistor somewhere in between, it doesn't matter whether it goes before or after the LED, as long as it's in series. 

Your LED should be lit up, and once you add some sort of switching mechanism (just interrupt one of the wires going to the battery pack with the switch) your static LED should be stage-ready. If you find that it's too bright, you can increase the value of your resistor (and conversely, to make it brighter, reduce the value, but be aware that if you try to run more current than the continuous value in the specifications of the LED, you will probably significantly shorten the life of the LED, and possibly destroy it outright.) 

I hope this is helpful to some of you, look for more on the topic soonish. 

Bits and Baubles, or the components you'll use.

If you follow me on twitter, you probably have seen me ramble on about LEDs. I think they're great, and believe they're one of the singularly most useful components a theatrical artist can keep stocked. I get most of mine from Super Bright LEDs. They have a good selection of products suitable for use in props and practicals, and their store is easy to browse, providing good information about each part. (I am a big fan of these in particular).

If you're getting into electronics for the first time, I recommend picking up some kind of starter kits for basic components: resistors, capacitors and maybe some other sundry bits. These basic components are important when it comes time to build any circuits. Don't forget to pick up that new Arduino!

That kit at SparkFun includes a few linear regulators, which will be an important thing to have on hand if you build your LED related props the way I do.

Getting power to the project is something you can accomplish in a few different ways. If it's a hand prop, then batteries are the obvious choice. The Arduino board contains regulators, and can easily powered with anything from 6-20v. This can be batteries, or a simple wall-wart if you project doesn't need to be mobile.

For initial design phases, I really recommend a decent-sized breadboard, this will allow you to build circuits without soldering, to test ideas or just play around with electrical concepts. You'll also want a multimeter, either a basic one, which will serve you just fine as long as you remember to turn it off, or a slightly fancier one. Auto-ranging is a nice feature to have, and might save you from blowing a fuse.

A soldering iron is important, and I will never recommend something from radio shack. This seems like a decent option, for relatively little cash. I'll admit my own soldering station is fancier, but I'm particular about my tools.

Basic hand tools, diagonal cutters, needlenose pliers, maybe one of those fancy automatic wire strippers. Hookup wire. Maybe some switches and cheap, low-power LEDs for output purposes. If you stick with electronics you'll see yourself gathering a fair bit of stuff, but it's all useful.

I don't think I've missed anything that you'll want to get started playing, but if you've got any questions definitely let me know.

The Arduino in theatre, or why you should be putting computers in your sets.

I've decided that this subject might need to be split into a couple parts, for my own sanity in the organization of information, if nothing else.

For my money, the Arduino is the greatest thing to be available to theatre props and electrics departments for a long time. This $30 board gives anyone with a computer easy access to low-level computing. Microcontrollers have a lot going for them: They're cheap, they're tiny, and you can power them just about however you'd like. Until the development of the Arduino, there was a significant technical barrier to entry. One had to purchase a programmer and deal with datasheets hundreds of pages long. To accomplish basic tasks, registers had to be massaged and timers coaxed.

An example of running an atmega328 on protoboard.
The only support components here are the crystal just
to the right of the chip, the two capacitors, and whatever
you decide to use to provide 5v power.

No more. The Arduino platform offers the user an inexpensive, all-in-one prototyping and development platform. Using the capable Atmega 328, the Arduino offers plenty of I/O, flash and RAM for any prop/practical related purposes. Taking your Arduino projects off the dev board is trivial, and with the ability to purchase mega328 chips with the Arduino bootloader pre-installed for $5.50 (with the required support components costing another few dollars) any number of places online means your projects can fit anywhere you can find space for a small protoboard, available at your local decently-stocked Radio Shack.

A microcontroller is a small computer, built into a single chip. These computers contain everything needed to run programs, and offer basic logic-level outputs and inputs. They can be used for something as simple as blinking some LEDs in a repeated pattern, or as complex as your imagination allows. In the world of theatre, they allow us to build small, low-power dynamic effects that can fit anywhere, be built very quickly, and updated 'in-system' for fine-tuning.

Arduino is programmed with easy-to-read, C++-like syntax called Wiring. Here's a sample, from my latest project:

void increment() {
    for(j = 0; j < 4; j++) 
      values[j] += directions[j]; 
      analogWrite(leds[j], values[j]); 
      delay(10);     
}   
    for(i = 0; i < 4; i++) { 
      if (values[i] < 25 or values[i] > 175) { 
      directions[i] *= -1; 
    }
  }
}

As you can see, if you've done any programming at all in the past, this is pretty straightforward. The really useful additions are commands like 'analogWrite()' which offer easy, one-line access to powerful features of the microcontroller. analogWrite() is used to set a PWM (pulse-width modulation) level to one of the output pins, allowing you to easily dim an LED or control the speed of a motor.

The biggest strength of this approach to dynamic effects, in my mind, is that they can be programmed and put into place, then powered from a dimmer. This means you can have complex effects anywhere you have a free dimmer, without the need to run a control signal. Alternatively, plenty of folks have implemented DMX on the Arduino and other microcontrollers (and this is actually on my list of projects to tackle), meaning you could easily assemble inexpensive automation controllers or anything else you'd like to control from your light console.

Stuff everything in a box and hide it.

In my next post, in the next day or two, I intend to delve into the basic electronics knowledge you'll need to start building the most interesting props and practicals you've ever used. Stay tuned.

On knowing

I know a lot about my field. I'll be the first to tell you that I have a lot more to learn, but I have a wide knowledge base, and I'm proud of that.

I think I've briefly mentioned the feeling that I get sometimes, in which I think to myself, "My area of expertise seems somewhat simplistic." I think that because I look back on my engineering classes, and all the things I didn't know then, and I feel convinced that I could teach anyone what I know in short order. But if I really sit down and ponder it, I know that's not true. I know that while perhaps a majority of the concepts related to the nitty-gritty of my job aren't extremely difficult (for example, it's not hard to understand the purpose of most of the hardware involved with stage lighting. There is a lot of it though) and most of the skills are not beyond a precocious high schooler. That being the case, it is a very wide skill set that takes years to accumulate.

I sometimes struggle with the idea that perhaps my profession is below my potential, just because so many of the skills seem so basic. If it wasn't for constant reminders in the form of inexperienced crewmembers, I might forget that it's not inherently obvious what to do with DMX or how it is a gobo functions. I might forget that people won't immediately understand what rotating the lamp/lens of a PAR would do to the light, or why you shouldn't touch high output halogen lamps.

I once tried to teach, in brief, a group of people about the very basics of operating the sound equipment at my college. Twelve seconds into my planned lecture, I realized that I hadn't communicated basic ideas about gain structures and the layout of a sound board that were, in my opinion, vital to any real understanding of the subject. I stumbled through, but it really opened my eyes to the concept of intrinsic knowledge.

I do wonder, though, if an electrical engineer ever feels that he's not living up to his potential? I could convey a lot more about being a master electrician in an afternoon than he could about being an engineer, I think. At least as far as useful fundamental skills go.

What kind of day is it?

I don't think I'll ever be able to walk into a space in the morning and tell you what the day's going to be like. I mean that in the most basic sense, that I just can't tell, at 8am, whether at lunchtime I'll be where I want to be. There are too many factors involved that are beyond my control.

Once, I discovered that the local crew had, instead of using the paperwork provided as part of the advance, created their own instrument schedule for the purpose of documenting circuits. Needless to say, I was, and still am, confused by that. They had gone so far as to rename positions (which is especially baffling, to me) pretty extensively.

My immediate course of action was to ask them to print out a copy of my instrument schedule and transfer circuit information. Well, they printed out the channel hookup, which didn't make the job easier for the girl they had doing the copying. It was then we discovered that the house-created paperwork had at least a few errors in it, such as specials being listed in two positions. When they handed me my channel hookup and I started my patch. Once I started checking channels, stuff just wasn't right, it didn't make the transition from paper to paper well.

The point of this is that here was a day that was going pretty well, my mover hang was fast and relatively uncomplicated, cabling wasn't a huge headache to deal with, my sound towers got hung pretty quickly and I even had my full balcony rail position, but now I had to have the electrician do a dimmer check. Once we got the circuits sorted out, they powered through what was probably the fastest focus I've ever had, and I knocked out my mover focus and we were more or less ready to go with plenty of time, in spite of a 7pm curtain.

Up until the trouble reared its head, I had no reason to believe this wouldn't be my best day yet, and it almost could have been, even in a challenging space. At the end of the night the crew set a record for load-out, the TD nailed a great pack on the truck and we were out of there. There was just that one little difficulty that no one could have expected that was the wrench in the works.

Admittedly, the fluid and unpredictable nature of the business is part of its allure for me, but sometimes I wonder if I'll ever get to a point where this kind of completely unexpected speed bump won't phase me too much.

Tomorrow, I hear, our space is going to be challenging. We'll see how it goes. Until next time.

On One-Offs

Don't get me wrong. I love what I do, and can't imagine doing anything different. I love touring, I love doing theatre, what else could I ask for but to do both at the same time?

What I don't love is what the one-nighter does to touring. I wake up at seven in some new city, pile off the bus and into the venue. I push through load in and the show and load out, finishing up after midnight. Then we get on the bus and start driving to another city... the next morning I wake up at seven and do it all over again.

I would just love to have the chance to explore some. To see some sights, even if they aren't the sights, you know? I want to take some pictures, enjoy some places.

After summer, my goal is to land a job with a company that'll land me in a city for two or three days at a time. That's a pretty decent goal, I think.

Changing Roles

So, as I've mentioned, I am on the road as ME for The 39 Steps.

In my last post I touched briefly on what I believe to be my greatest stumbling block: acting in a supervisory role. In my previous work, it's mostly fallen to me to do the vast majority of the work, from physical to mental. Every time I've been an ME I've participated in a large portion of the hang and focus myself. Don't get me wrong, I've led crews before. I've taught, directed and scolded. But I've never been in quite the position I am now. I hold sole responsibility for the implementation of my show the way it was designed, and to that end I have a number of crew members that require specific direction to accomplish tasks. In order to finish my load in, I simply can not be 'hands on' and do most of the physical work myself. I have time to hang one of my movers, just to make sure the crew knows how. I've got time to demonstrate what I mean by, 'Run the data to that end,' and have to trust that it gets done. I'm learning to be completely explicit about what I need (one day the strobes missed the DMX train, for example, costing me a good ten minutes while I fixed it) and that I can't sugar coat my requests. There simply isn't time.

I have trouble with that. I find it difficult to be stern. It's hard for me to say "This is what I need and I would like it done five minutes ago." Even though I usually actually want it done ten minutes ago, I just feel like such a tool being any sort of 'boss.'

The worst, though, is when I send a couple folks to retrieve circuiting information or to hang a position, only to discover at my next check-in with that crew that what they've done is just wrong. Now I have to be even more stern, and I just hate that. I don't want to be perceived as 'that dick roadie,' because I really don't think I am. It does seem, though, that local crews don't feel the time crunch the same way, and that's a problem. Why should they rush around if they don't know how desperately behind I feel?

Right now my schedule is something like this:

8am - Truck opens and boxes start coming. I know now how I would approach labeling cases, the next time I'm gearing up for a tour. It's not how I did it this time. Hopefully by now I've taped my electrics so the crew can just start hanging once I get the pipe.

10:30 - First break. My goal at this point is to have my fixtures hung and cabled, and the cables run to the distro. At this point I'll set people on getting my atmospherics set up and cabled, and set up my board. This leads into:

12:00 - Lunch. Right now I would be in a great place if I was ready to start focus right after lunch, though so far there have inevitably been problems preventing that. Conventional focus can be time consuming for any variety of reasons, but it's getting better. The majority of my instrumentation is dedicated to six washes, so with a competent crew I can describe the first area in detail and then just focus the hotspot and they'll get the cuts while I get the next light up. Usually the spikes are going down while I start my focus, so when I've finished the FOH washes I can hit the specials on that pipe.

After I finish conventional focus, I have to hit mover focus. I'm getting more confident in this, but a lot of it still comes down to my SM/ASM to tell me where stuff is. I've only seen this show from the front once, during an understudy rehearsal, which is a big hindrance for me. I just don't know what these things are supposed to look like, so I'm doing what I can.

~6:00 - Dinner. I'm getting to the point where my focus is completely done at this point, and now I can check my practicals and presets, and do whatever other pre-show stuff I have.

--

It's a lot of stuff, and definitely the most responsibility I've ever been saddled with. I wouldn't trade it for anything, and I know I've gained a boatload of new skills that will help carry me forward in my career.

I am definitely looking forward to a summer rep season, though.

On the road again.

So my last post was depressing.

Things have, since that last entry, changed quite a bit. I've just hit the road with a national tour of The 39 Steps. We had a somewhat difficult tech process, owing mostly, I think, to a master carpenter who broke his ankle days before he was supposed to fly out.

Difficult tech weeks are part of the business, though, shit happens right? Well, we got through it. My first load in was... not good. I was much less prepared than I thought I was, and the show looked terrible. I was dealing with a local crew who moved at a fairly glacial pace, and just couldn't seem to complete a hang position without a mistake or two, and circuit information was just not recorded well or consistently.

I pushed through as much of my focus as I could, and managed to at least light the stage, though the show didn't look much like its intended design. I was also learning how to run the Hog, as our tech process had left me with no time to familiarize myself with it. (The lack of any kind of ability to directly control dimmers is a huge downfall in my opinion.)

We did two nights in our first venue. The second day I was able to sort out the circuiting information by being a little more stern than I like with the local crew, but we got it done. Then I was able to push through my focus and get shit looking right. The second show looked great, I'm told, and I'm much happier about it.

We're en route to Iowa now, having stopped in Missouri for the day. That's all I've got for now, I'll try to write about my experiences living on the road later.

Oh, by the way, I have already lined up my summer job as Principle Elec/Board op at Shakespeare & Co. in MA.

Will hang lights, reinforce sound for food

The job search might be the single most soul-crushing and existence sapping experience I know. Being possessed of a somewhat... specialized skillset and no desire to perform duties unrelated to those skills, my work opportunities are painfully limited. I know that my current mood would only deepen further and further under the saddle of employ in the field of fry cookery or shelf stocking or customer service punching bag, so for as long as I can humanly avoid activities such as that, I will continue to fight.

Today I was informed I would not be receiving a position I was very excited about. It was close to home, it was enough hours to support myself, I had a chance to sublet an apartment with some excellent people, and most of all it was in my field. It's not to be. I don't know how to express the disappointment that comes with news like that, the sheer pointless patina that everything adopts in that sort of light.

So now what do I do? Continue sending out resumes I guess. Hope that weird interview I had turns into a summer stock at least. Who the hell knows what I'll do for that fall, or until may. What if I don't get a summer job? I'm so tired of wasting all of my time.

The now.

I haven't written anything in particular for a while. It's tough to find the inspiration, motivation, and time for writing. I need to have all three at once, and they just don't coincide often. Now, in the steady grasp of sleeplessness, might as well be as good a time as any.

Tonight we're in Brooklyn, with a show at Brooklyn College tomorrow. Our sound tech (who toured with this company last fall) insists that tomorrow will be an excellent crew, and numerous. That's always nice. Today's (Monday?) crew was pretty exceptional. We had already played the space (Strand Theatre, Lakewood) once on this tour, and just last week Encore went through. They're well practiced this year. I think it was the fastest in we've had. The out was up there, too, but I think it was a few minutes shy of the record. I didn't write the record down so it's hard to be sure.

We've only got two more shows this week, and then we're off for thanksgiving until Monday. We'll be spending the break on Long Island, so I might spend some time exploring the city in somewhat greater detail than I have had the opportunity to, so far. So far, in my somewhat limited experience, I do like New York. It's a whole other sort of thing from any of the cities I've spent time in previously. Granted that's not much of a surprise to anyone, whether they've been here or not, but it is significant enough, I think, to be mentioned; even though we all know it already.

The tour is coming, rapidly, to a close. I can't say I find myself disappointed, and if you've read any of my recent writings I think you'd guess that without any mention. I like the idea of being on the road, but I want to be on the road with a show that challenges me, that gives me more than 15 minutes or so a day of troubleshooting, even perhaps a show into which I had some level of input. I know that I couldn't stomach touring forever. It's not the environment I need, but I do like the travel, the seeing of new places.

So where do I want to be? Really with any company that's regularly producing work (New, old, original, rehashed) with a proper creative team (so community theatre is not a great option, in most cases) who is actually interested in expressing something beyond the text. What role do I envision myself filling there? To be honest I think I could be happy in my electrician/carpenter/welder/audio engineer/wizard role from college, or in a more standard ME position, or as an LD, or some blend of all of those. Give me the chance to express myself and to create again. That's all I really want. And probably all I really need.