The first part of the tutorial looks inside of a Brushless DC Motor, or, BLDC. Then I show a discrete transistor circuit that can drive one. Of course, you’ll need a Microcontroller like an Arduino to drive it! Lastly, I briefly talk about an ESC.
Overall, a BLDC is better than a Brushed DC Motor (talked about those on #20) because:
- There are no brushes to wear out
- No sparks when the motor spins
- You can get way faster RPMs out of a BLDC.
Check out the AddOhms #21: Brushless DC (BLDC) Motors. Show notes are available here.
Supplyframe Hardware has published a video of a talk I gave in July 2017. This talk was at HDDG 22. The focus of my discussion was how an oscilloscope’s trigger circuit works. I built on that and talked about some of the behind-the-scenes stuff of what is going on with a digital oscilloscope. (You can download my HDDG 22 slides here.)
If you have any interest in retro computing or technology, The 8-Bit Guy is one of the best YouTube Channels. His latest video hits a little closer to home. He shows how to Character LCDs work and how to hook them up. He always does a great job with his videos, so I encourage you to check out some of his others.
He’s has some other good videos such as the one on how 8-bit video game graphics worked and, one of my favorites, how disk drives worked.
It is commonly known that ceramic capacitors change capacitance with applied voltage. What isn’t always as well known is how strong this effect can be and why it occurs. At KEMET we’ve put together a technical video that answers that question.
What is Ask An FAE?
Ask An FAE is a new video series we launched at my day job, KEMET. An FAE is a field application engineer. These engineers are very common in the electronics industry. Companies like KEMET, where I work, have FAEs who meet with customers to answer technical (and very detailed) questions about how to use their products. In UBM’s Mind of an Engineer survey, FAEs were ranked as one of the top information sources for design engineers.
At KEMET we decide to use FAEs to answer the questions. While I’m not an FAE today, I was in the past and happy to kick off the series with our CEO.
Check out KEMET’s Ask An FAE
ArcAttack is a band that performs at the Bay Area Maker Fare, among other places. They feature massive signing Telsa coils. (Here’s a video I show when I saw ArcAttack in 2013.) Singing Telsa coils are awesome. Everyone knows that. Which is why I found when Dianna Cowern, the Physics Girl, visited the band ArcAttack, electromagnets are just as cool. In addition to talking about their music, ArcAttack’s Joe does something amazing. He splits an aluminum soda can with just an electromagnet.
There are a few other neat tricks and some slow-motion stuff too. Near the end, he compresses a quarter with the scariest magnet setup I’ve ever seen. This video is definitely worth watching if you like anything related to Tesla coils–or electricity!
Ben Krasnow from Applied Science on YouTube uses his Electron Microscope to compare spinning media. The part of the video that caught my attention is the Vinyl Record. Not only does he show the groove and needle, but he puts it in motion! It’s a great look at how this technology works.
Additionally, I loved how he went into detail about how to prep the record for use in the electron microscope. (Spoiler: he had to make the record and needle conductive.) After the vinyl, he also compares a CD and DVD. The twist is that he also shows how a Capacitance Electronic Disc (CED) compares to the vinyl. You never heard of a CED?
Neither had I until Techmoan covered the RCA CED Videodisc on his YouTube channel. It appears over 1,700 movies were released in the United States alone. Check out the both videos for details on CED.
If you enjoy Electron Microscope pictures like I do, then you’ll enjoy this video.
How a Brushed DC Motor works and how to use them
This Addohms Electronics Motor Tutorial goes into the third dimension. Using a 3D model, we show what makes a brushed DC motor, well, a “brushed motor.” (Hint: It’s the brushes!) Then, as usual, we break down two simple ways to control them with a microcontroller like the Arduino. You can use a single BJT Transistor (remember those from #10?), build a discrete H-Bridge to go in both directions, or use a popular H-Bridge chip like the L293D or L298D. (Notice the ‘D’!)
The video starts with a couple of (mixed) motor examples. Do you know what a “stator” or “rotor” is? If not, that’s okay because that’s one of the first things we explain. After that, we add part like the commutator and brushes to make the Brushed DC Motor. After that is control with a transistor and an explosive reason you need a protection diode. 🙂 Then we show how an H-Bridge Works. Lastly, the advantages and disadvantages of this motor type.
You can see the full Brushed DC Motor Tutorial on YouTube or on the AddOhms page.
A couple of weeks ago I wrote about four current flow direction myths. As a follow up to that popular post, I decided to dedicate this month’s AddOhms electronics tutorial video to Current Flow. In episode #19, I tackle the question of which way does current flow.
You might have heard about “conventional flow” and “electron flow.” In conventional flow, we assume that current flows from the positive voltage towards the negative voltage. In digital, the “negative voltage” is usually called ground. However, that’s not how the electrons move nor is it how they carry the charge around a circuit path.
Electron flow is the description of how electrons carry a charge. Which is the negative voltage towards the positive? This confusion is a result of Ben Franklin mistakingly identifying how electrons moved so many years ago. Yet, we have kept the “positive” and “negative” labels as they are today.
The key though is that it doesn’t matter which method you use to analyze a circuit. Electrons move in a closed path. So whether they travel from positive to negative or from negative to positive, doesn’t matter!
AddOhms #19: Current Flow Direction
Check out the full AddOhms Electronics Video Tutorial on Which Way Does Current Flow on the AddOhms YouTube Channel.
I was invited to speak at the 11th Hardware Developers Didactic Galactic group at the Supplyframe office in San Francisco. I talked about the misconception that capacitors are a simple device.
Chris Gammell recorded the discussion and posted it via PHY Media. This video is about 50 minutes.
In this talk, I break down a few things to know about Ceramic, Aluminum, Tantalum, and Supercapacitors. You can see the full video via PHY Media’s YouTube Channel: They’re JUST Capacitors. For links and the slides, check out this post.
Quick timelapse video of Bright Bricks building a life-size BB-8 unit. Surprising to me was that I always imagined these builds solid with LEGO pieces. Turns out, they are built an internal structure, which makes more sense really. Either way, watching this short LEGO BB-8 build is fun.