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

Mooshimeter Review – Smartphone Multimeter

Can your phone replace your DMM?

Mooshimeter Review

For fifteen years I used my Radio Shack 22-168A digital multimeter as my go-to meter. A couple of years ago I bought a Fluke 115. Not because the RS meter lacked a measurement, but because I wanted a backlit screen. Here’s the crazy thing though in 20 years of multimeter development, there hasn’t been much innovation. Well outside of maybe auto-ranging.

All three meters I have, plus the Virtual Bench I reviewed about a year ago all continue to have the same limitation: they can only perform one measurement at a time. That’s one feature that makes my latest meter, the Mooshimeter, unique. It can measure both voltage and current at the same time. Oh, and it doesn’t have a screen.

Continue Reading »

Fading LED: analogWrite millis() Example

Add a fading LED without delay()

Fading LED millis() Example

It’s a well-known fact of engineering: LEDs make everything look better. And that means a Fading LED is even better. Using Arduino’s analogWrite(), fading a LED is just a matter of a loop. If you use delay(), you can’t easily add other actions. What can you do? Well, Fading a LED with millis() is pretty simple. Here’s the code to do it and a quick explanation.

Continue Reading »

Measure PWM Current with a Modified Moving Average

How do you measure a signal that keeps changing?

Measure PWM Current with MMA

Pulse Width Modulation (PWM) makes it possible to dim lights, control the speed of motors, and (with the help of filters) generate analog reference voltages. When measuring the voltage or current of a PWM signal, there are unique challenges. You can use this tutorial to measure PWM current with a modified moving average (MMA).

Continue Reading »

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’!)

Tutorial Contents

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.

Social Media Guide for Engineers, a How-To

Click here to find the 1 magic trick to using social media ;)

Social Media Guide for Engineers

Engineers are notorious introverts. An untrue generalization is that introverts hate being social. Like all humans, introverts are social creatures. We just prefer only to discuss the topics which are of interest to us. We will listen to anything. This social media guide for engineers explains why and how you can participate in social media, without being social.

Let’s address something head-on. Gone are the days of just “here’s what I ate” or “I’m in the bathroom” social posts. Social media channels are mature platforms for communication. Sure, junk still exists. However. You can filter out the signal from the noise when you following my social media guide for engineers.

Continue Reading »

3D Printer Tips I wish I knew 3 years ago

Here's how I stopped getting annoyed

3d printer tips by bald engineer

While I bought my 3D printer a couple of years ago, in March of this year, it only had 75 hours of use. Since March, my counter is over 300 hours. Why? After spending some time doing the right tweaks my printer is printing crazy good. Here are some of my 3D printer tips.

Maybe you’re in the market for a printer, use one at school, get access to one through a maker space, or (like me) used to use yours for a desk ornament, these 3D printer tips are likely to help.

Continue Reading »

5 Common Arduino Programming Mistakes

Code compiles but doesn't work? Check these 5 mistakes.

5 common arduino programming mistakes

Whenever someone sends me some code that doesn’t work, there are a few common Arduino programming mistakes that I check. Some of these mistakes I make myself.  In most cases my code will compile just fine. Sometimes, these mistakes won’t generate any compiler error.

When my Arduino code is acting up, these are the first things I check. Here are my 5 common Arduino programming mistakes, I use to debug non-working code.

Continue Reading »

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.

Arduino Bootloader, What is it?

This simple code does important things

arduino bootloader

Almost all microcontroller (and microprocessor) development systems use some form of a bootloader. Often called firmware, mistakenly, the Arduino bootloader is one example. Since it is a rather popular platform, let’s use it as an example. Let’s talk about what a bootloader does and how it works.

When a microcontroller turns on, it only knows how to do one thing.  Typically, that one thing is to run an instruction found at a specific memory location. Often this location address 0x0000, but not always. Usually, this memory location will contain a jump instruction to another place in memory, which is the start of the user program. The bootloader, however, exists in a slightly separate memory space from the user program.

On power-up or reset, a bootloader is a section of program memory that runs before the main code runs. It can be used to setup the microcontroller or provide limited ability to update the main program’s code.

Continue Reading »