Friday, May 30, 2014

Book Recommendation (Two, Actually...)

After setting up my 5V DC regulated power supply, I was left with some questions about capacitors. I sort of understand the chemistry involved, and I know the bare necessities for selecting capacitors and how to wire them properly into a circuit, but there's still a lot I don't know. I'm the kind of person who really digs into a subject when I'm interested, so I often head to my existing library before looking elsewhere for information on a subject. Luckily, I had two books on the shelf that helped expand my knowledge of capacitors and provided me with some basic circuits that use capacitors in interesting ways.

The first book is from an author you're probably already familiar with -- The Encyclopedia of Electronic Components Volume 1 by Charles Platt. (No, I don't own stock in Maker Media!) I bought this book back in 2012 after a quick scan of its contents and it has turned into a very reliable and useful source of info. Two more volumes are planned, but this one covers Power Sources & Conversion -- namely resistors, capacitors, inductors, switches, encoders, relays and transistors. Plus power sources. It's right there in the title. (Volume 2 is showing a September 2014 release date.)

This is not a book you just sit down and read. Maybe you can... but not me. Instead, I've used it a number of times over the last few years as a reference for finding the right component for a circuit. In the case of setting up my regulated power supply and my questions about capacitors, I turned to Chapter 12 and read through the 15-page section on capacitors... it's by no means comprehensive, and if you're looking for actual circuit schematics, that's not what the book is really about. But still... definitely recommended reading for what I call Experiment 0 that uses two different capacitors. My version uses three because I lacked a .33 microfarad and needed to put a 0.1 and 0.22 in parallel to mimic the behavior. Right there on page 106, when "two or more capacitors are wired in parallel, their total capacitance is the sum of their separate capacitance." Put capacitors in series, and you might get a surprise you weren't expecting... or not.

I've gotten quite a bit from this book -- helped me with understanding stepper motors better as well as motors in general. I'm now re-reading the chapter on voltage regulators (that other key component used in your regulated power supply). Like I said... I tend to sink myself in a subject when I have questions.

It's a great resource, especially if you're working your way through either of Charles' electronics books.

The second book is a bit older, but I've had fun with it here and there. It's Forrest M. Mims III's Getting Started in Electronics. It's a bit unusual to read at first... hand sketches and hand written notes on lined paper. But you'll be amazed at what extra info you'll pick up in its128 pages.

I seemed to recall it had something about voltage regulation, and sure enough on page 101 there's a simple circuit labeled Voltage Regulator, but this one uses silicon diodes and a resistor... no capacitor and no voltage regulator component needed. As a matter of fact, there's another version on page 103 that uses what's called a Zener diode. (And look at that... Zener diodes are covered in Chapter 26 of Charles' Encyclopedia!) There's even the simple algebra equations needed to calculate the desired diode value(s) and current and resistor value. Very useful!

This book is just too interesting. Want to wire up a simple voltage doubler? Page 102, but take note of the WARNING about high voltage! Oh, look... schematics for voltage triplers and quadruplers. Those could come in handy.

Page 100 to 128 provides 100 electronic circuits to play around with and use. (Hmmm... maybe another Hands-On blog-project idea... wire up all 100 circuits.)

Great book. Love the hand sketches of components and the easy-to-read notes -- Mr. Mims has some excellent hand writing.

Alright... back to prepping Experiment 2.

Thursday, May 29, 2014

Experiment 1 (Chapter 1) : Glue and Glowing LED

Okay, time to get moving. Experiment 1 ranks up there with Make: Electronics' (Book 1) unusual requests to lick a battery, burn out a battery and fuse, and cut open a relay. This one doesn't even involve a breadboard... just a simple piece of cardboard. 

The setup is simple -- wire up a 2N2222 transistor so it provides current to an LED. There's some important discussion in this chapter on the difference between a 2N2222 and P2N2222 and how the leads are oriented. I also learned a nice mnemonic for NPN transistor identification -- NPN for arrow "Never Points iN." I can remember that.

The other components used in Experiment 1 are a simple 9V battery and harness, a 220 ohm resistor, and some patch cords. I also added in two copper gator clips, but I'll tell you now that they were a bit of a pain because they don't hold two wires together well. Use the tighter clips with the rubberized covers if you have them. (I do have them, but was too lazy to go digging... yet another reason for me to take this weekend and go through all my electronics components and tools and supplies and inventory exactly what I have.) Oh, and you'll need some white glue and two jumper wires to keep the glue off of your clips.

After wiring it up, I touched one of the jumper wires very near the beginning of the glue trail -- near the thicker end. Sure enough, the LED lights up. And just as the text explains, as I moved the jumper wire further from the thicker end of the glue trail, the LED fades and fades until I get nothing. You can watch a video of this first test below.

After testing this "circuit," the text suggest removing the transistor completely to see if you get the same results. If you have a solid understanding of how the purpose of this particular transistor, then you already know what the results will be -- here's another video that shows those results.

For the next video, it's a bit tough to tell but the transistor is reversed... I basically just flipped it over so the CBE leads are now EBC (reading from the top of the cardboard down). The only way to really tell is that the rounded part of the transistor is now facing up (to me) instead of down. Charles explains that using a transistor incorrectly can damage it, and that makes sense. But I had to test it anyway. Here's the results:

My final test for Experiment 1 was to take the "damaged" transistor and put it back in the circuit in its original configuration. As the video shows below, I still get a positive result (LED lights up), but I know I cannot trust this transistor in future circuits.

So, I've tucked this damaged transistor into an envelope (and yes, I know I wrote the label incorrectly -- all those Ps and Ns and 2s get confusing after a while, and yes, I know it's Experiment 2, not 3) and am saving it for the next experiment -- the final paragraph in this chapter suggests using it in Experiment 2 to test its performance against a new transistor... and I plan on doing just that. As you can also see, I have no issues writing in my book and I certainly highlight a LOT of stuff. Not sure what your own plan is for working through the book, but I typically read through a chapter twice... once to get a general feel for the chapter's contents and then a second time where I highlight components I'll need, variations that I should perform, and other important facts that might impact later experiments.
Saving the damaged transistor for Experiment 2.

One little mini-experiment from Chapter 1 that I did not perform was testing the resistance of de-ionized water. I performed a version of this back in Exercise 1 for Book 1, and my understanding of how salt ions increase conductivity in water is pretty good. Feel free to repeat this exercise if you didn't already do it while working through Make: Electronics.

Wednesday, May 28, 2014

Off-Topic: A Simple Electronics Project

As I continue to read forward into the book, I'm quickly realizing that I won't be posting updates on experiments every day. Some of these experiments are monsters -- likely to take days or even a week of careful wiring and testing before I can share results. Charles warned me about this at Maker Faire, but did I listen? Nope.

My Bluetooth-powered Arcade Controller
So, in between writing up my results and thoughts on the 36 experiments in the book, I figure I can share a few odds and ends here and there, and maybe point readers to some interesting books or projects or websites I've found (or find) that might be relevant to the electronics hobby.

I'll start out with one I built a few weeks back. I wrote about this project in greater detail for and you can read the original post here, but here's the nutshell version:

I like to play old Atari 2600 games as well as 80s/90s-style arcade games on my computer and I've been wanting to introduce my 7 year old (and maybe my 4 year old) to some of these games. I found an interesting project over at involving creating a small handheld box with a joystick and a few buttons on top... pair it up via Bluetooth to a computer or laptop and play away. I also have a Mac laptop and an Apple TV connected to the flatscreen in our living room, allowing me to put whatever is on the screen of my laptop on the big screen... this was looking good.

Some of the components for building the Arcade Controller.
Total parts purchased were under $40 (if I remember correctly) for the tiny Bluetooth keyboard device, some buttons, and a joystick. I bought the box for $3 or $4 at a hobby shop. The small Bluetooth device required a tiny amount of soldering. I painted the thing purple, powered it with some rechargeable AAA batteries (and a battery harness I already owned), and what do you know... Atari 2600 games once again on a big TV screen. (I've also really been enjoying playing Joust on my flatscreen with some unusual looks from the family.)

Here's a link to the online instructions to build your own.

And here's a link to Stella, the Atari 2600 emulator.

And here's a link to grab some of the Atari 2600 games. (I own a LOT of original cartridges, so I don't think I'm violating any laws here...)

The Atari 2600 game Adventure on a flatscreen.
Yeah, that's Adventure. And yes, the very first Easter Egg is still tucked in there if you know where to look. (I found it back when I was 7 or 8 and had no idea what it was. It was totally accidental, using the Bridge at one particular point and hearing that blip that indicated you'd picked something up... to see that glowing little dot was quite strange.)

Total time to wire it all up was about an hour... drilling the holes and painting the box actually took the most time. I highly recommend hunting down those special jumper wires that insert onto headers... saved a LOT of headache not having to solder to header posts... which I hate doing. Radio Shack Part # 2760151 and worth every penny.

You'll get some practice on using your multimeter to verify connections as well as with your soldering rig. Follow the instructions carefully and you'll also understand how the joystick works -- each position (Up, Down, Left, Right) is nothing but a signal that is triggered by four small switches inside the joystick device. These are interpreted as keyboard presses -- the Stella or MAME software that runs games uses keyboard presses to simulate firing, jumping, etc... you're just using the small Bluetooth device to send a handful of signals as keyboard presses to your computer. It's really quite cool.

A peek inside the box as wiring was being done.

Tuesday, May 27, 2014

Experiment 0 (Preface): I Have The POWER!

Multimeter reading 4.91 volts -- close enough to 5V for me to be happy.
Today I wired up the schematic from Figure S-2 (page xxvi of the Preface) on one of my new breadboards. I didn't make it all pretty like the one that Charles wired up for Figure S-1, but I'll probably clean it up a bit once I get a simple problem solved (more on that in a moment), but as you can see here, it does deliver almost 5V (4.9V give or take).

My 5VDC regulated power supply is now working... but it doesn't look exactly like the one in Figure S-2. First, I didn't have a 0.33 microfarad capacitor. (Actually, I probably do, but sometime in the past my nice organized capacitor collection became disorganized. I'm not going to point fingers at either the 7 or 4 year old boys in my household, but I'm certainly looking in their direction.)

Closeup of 5V DC Regulated Power Supply
To solve this, I went back and refreshed my memory on combining capacitors. I seem to recall that putting capacitors in parallel (versus series) was the way you added their values together. I sure hope this is true, because that's exactly what I did. I put a 0.1 microfarad and a 0.22 microfarad in parallel and no puffs of smoke have appeared.

As with Figure S-2, I added in a green LED but the more I think about it a red LED is more likely to make someone think *DANGER* so I'll swap that out later. I had plenty of 2.2k resistors in my collection as well.

Teeny tiny switch -- $0.95US
One other difference in my power supply is the On/Off switch. Charles uses what appears to be a SPDT switch but I could not find the PC-mount type to save my life. Radio Shack didn't have it, and even my trusty Atlanta-based ACK Electronics store was coming up blank until one of the associates there pulled out this little gem of a switch -- it has the low profile of a simple pushbutton component and inserted quite easily into the breadboard. Total cost -- $0.95US.

I'm not using a 9V battery. Instead, I pulled out the variable wall wart I purchased back when I was working through Make: Electronics. The ends are stripped and I soldered on a piece of red wire and black wire and added some shrink wrap to identify the leads. Those go into the breadboard as shown in Figure S-1 and after double-checking my wiring... I flipped the little power switch. The LED began to glow and no smoke was seen coming from either capacitor. (Remember: if you're using capacitors that actually have polarity, wire them up the right way -- the black stripe on the side goes towards GND.)

Here's the video describing my setup:

If you've watched the video, you now see my slight problem. The breadboard doesn't have voltage continuity down the left or right side. Maybe this breadboard requires jumper wire to connect the power and GND lines, but since the breadboard came with no documentation the only way for me to be sure is to open one up. I'm going to test this problem with the other two breadboards -- if they have a continuous power and GND line, I'll cut this first one open and share a photo of its guts in a later post.

Reading 0V when jumper wires moved down a bit.
One final observation I'd like to make about this new breadboard -- the holes are tight! Inserting jumper wires and components was tricky, and a few bent posts required a pair of pliers to fix. While I like the idea of this breadboard and how it matches some perfboard, if I continue to have these issues inserting components and wire I may very well switch back to the old standard. I'm going to give these new breadboards a few tries before making a final call.

My next tasks are transferring this wiring to a new breadboard (or two) to test the continuity of the power and GND lines as well as the ability to easily insert wires and components PLUS testing out Experiment 1.

Monday, May 26, 2014

Still Gathering Supplies

I'm still gathering a few supplies before I begin documenting my work through the new experiments. I've read ahead through Experiment 6 and I'm fast realizing that I have a LOT of supplies already in my workshop although many components are buried in various boxes and containers!

NOTE TO SELF: come up with better organization solution for all the electronics stuff I've collected over the years!

Early in the book, Charles shows two analog gauges that he purchased to enhance Experiment 2. These gauges are NOT required for the experiment, but I do want to try and tackle any extra challenges or observations he recommends in the book, so...

I could not find the 0-10 microamp analog gauge he uses, but I did find a 0-20 microamp for about the same price. I did find the 0-50 milliamp analog gauge, however. The eBay seller is gardenthing and each device was approx $5US and shipping was free.

Hopefully any of you following along and wishing to own these two gauges will find the price the same on the items as well as free shipping. My total was $10.29US (no shipping charges) and I'll be sure to post a nice pretty picture when they arrive in a week or so.

Speaking of ordered equipment -- my three new breadboards arrived along with the jumper wire (three bundles, one per breadboard!). That order was placed on May 19 and the package arrived on May 24th. Not bad.

Variable voltage plug on left (from first book), three new breadboards on right.
These new breadboards are thinner... and inserting the voltage regulator required a bit more pressure to seat properly. I was worried I would bend the prongs, but it inserted okay with no damage. I may have to trim the leads on the variable voltage adapter (purchased during my work in the first book) so they can be inserted a bit deeper into the new breadboards... just feels like components must be inserted a bit further than with my older breadboard. Will have to experiment with this a bit, and I'll be sure to let you know what I find.

I'm almost ready to go... another day or two, and I should be tackling Experiment 1. Stay tuned...

Thursday, May 22, 2014

The New Breadboard

Just a quick note about breadboarding in the new Make: More Electronics book. For this new book, author Charles Platt chose to use a different breadboard design. This one has a single column of holes running down the left and right sides of the breadboard. The reasoning here (and I'm in agreement) is that having the traditional two columns (one red, one blue) running down both sides of a traditional breadboard can cause confusion for novices (and pros) as they wire up schematics. I know that I've fallen into the trap of inserting a wire into the wrong location many times.

Charles also points out that this breadboard layout also matches most designs of perfboard, so transferring a breadboarded project to perfboard is even easier.

In my quick searches, I was unable to find this type of breadboard locally, but I did manage to find them at a decent price on eBay per Charles' recommendation. I purchased three of them because I have a feeling I'll be wiring up multiple projects at once or possibly debugging a previous experiment while moving on to another one.

Here's a link to the one I bought -

The price is $5.89US and the seller tosses in a 65 piece jumper wire set -- and I can always use more jumper wire. Shipping was cheap, too $0.79US each.

If you find this type of breadboard locally or at a cheaper price, please share in the comments so other readers can obtain one or more at the lowest price possible. It's quite possible that MakerShed may eventually offer up a Parts Pack for the new book (as they did with the first book) that might include this type of breadboard, but right now I've heard nothing about a Parts Pack being considered.

Tuesday, May 20, 2014

The Book Is In My Hands!

Bought the very first copy at Maker Shed
I enjoyed my visit to Maker Faire 2014 in San Mateo, California this past weekend, and I was able to get my hands on a copy of Make: More Electronics.  (As a matter of fact, I bought the very first copy from Maker Shed as I walked in when the store opened, found the book immediately and was fourth in line... no one else had a copy, so GEEK moment!)

 Even better, Charles Platt was signing copies for buyers in Expo Hall a few hours later. Although I've communicated with him a number of times over the years as I worked through Make: Electronics, I had never actually met him until this weekend. It was a real pleasure to get to visit with him for a while and chat about a number of things, not just electronics.

On the flight home, I took the chance to read through a number of the early chapters as well as skim many more. It's going to be an interesting collection of projects to try out, and I'm looking forward to sharing my results here. If you're looking for some details on the book, here you are:

* 37 chapters and 2 appendices -- a total of 36 experiments/projects to perform

* As with the first book, this one is in full-color

* Appendix B contains very detailed components lists organized into groups of projects (experiments 1-14, 15-25, and 26-36) along with itemized project-by-project listings if you wish to purchase items on a per-experiment basis.

* Errata for the book can be found here -

I'm already collecting some tools and components as I prepare to start working through the 36 experiments. Surprisingly, I have a lot of stuff left over from my working through the experiments in Make: Electronics that will save me some money.

I can't say when I'll be starting my work on the book's projects, but it will be soon. Tomorrow? Unlikely? Next month? Too long to wait. Give me this week or next and I expect to have enough of my tools and components pulled together to get moving.

I'm also going to leave comments open for your own thoughts, questions, observations, etc. I'll leave comments open as long as they are not abused. If I start getting a lot of spam, I'll turn on the approval process that will require me to approve a comment before it's added -- just letting you know in advance that might be coming, so don't worry if your comments stop showing up immediately... I'll get to them.

Thanks for joining me for this project -- I learned so much during my explorations for Make: Electronics, and I'm certain that Make: More Electronics will provide just as much education for all of us working through the book.

Charles Platt (left) and me

Wednesday, May 14, 2014

Heading to Maker Faire!

My plan is to still get a copy of the print version of More Make: Electronics and to work through it and document my work. I see the book is scheduled for a May 29 release, but I'm attending Maker Faire this weekend (May 17-18, 2014) and crossing my fingers that advanced copies of the book may be on sale in the Maker Shed.

Once I get a copy, I'll do an initial scan of the book to determine what components I will need to gather -- this could take a few days or a few weeks. My electronics collection has grown substantially and now includes many more components and tools than I ever needed for the original book. Still, I suspect I will need to do some sourcing and pricing to find out how best to gather supplies and not spend a small fortune. It's quite possible that the Maker Shed may already be planning one or more Parts Packs as they did with the first book (that one had two Parts Packs created for it), so I'll check that out and ask around at the Shed and share what I learn here.

On a similar note, I will be teaching a basic introduction to electronics and robot building to some campers this summer. At this point, I have 22 kids signed up for a weeklong camp where we'll learn about the basics of voltage, current, resistance and capacitance as well as get some hands-on practice with reading schematics, wiring them up on a breadboard, soldering, and, of course, building a real robot. I've been looking forward to this for some time, and if the camp goes well my intention is to teach more each summer and at different locations. I've got a parts supplier and a curriculum in development that I will use this first camp to help refine. The camp is $300 per camper (and I'm told this is quite low for a camp of this nature -- other non-technical camps in and around Atlanta can run $400, $500, even $600 per week. My camp filled up fast (I had originally set the cap at 20, but two extra campers managed to sign up before the school where I'm hosting it pulled the plug), so apparently parents and kids are seeing the possibilities here.

At the end of the camp, I'm inviting the parents to come and listen to their kids talk about their experience, show off their robots, and I'll have a chance to point these parents to additional resources like the Make: Electronics book and the follow-up book.