Components on Bald Engineer

STOP! Using the Wrong Capacitors | Teardown 2024

Thu, 20 Jun 2024 02:04:11 +0000

Learn more about Teardown 2024 Google Slides Download Slides (PDF) Links Circuit Break Podcast #434: The Other VCC Circuit Break Podcast #141: It Depends MLCCs with James Lewis YouTube: Bald Engineer’s Capacitor Videos Hioki USA: Unlocking the Secrets of Capacitor Impedance Plots Murata: SimSurfing Yageo Group / KEMET: K-SIM

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Picking I2C Pull-Up Resistors (Correctly)

Thu, 07 Mar 2024 13:22:00 +0000

A long time ago, I made a video suggesting math was unnecessary to determine proper pull-up resistor values. Like most generalized statements, that suggestion is not always true. For example, in data buses like I2C, speeds like 400 kHz and 1 MHz are common. At those speeds, the pull-up resistor and the bus capacitance form an RC filter that fundamentally limits the data transmission speed. Or. It limits the range of pull-up resistor values. In this Workbench Wednesdays video, I show how to estimate I2C bus capacitance, measure that capacitance, and pick pull-up resistor values.

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Aluminum Polymer Capacitors on EE Journal's Chalk Talk

Mon, 30 Oct 2017 22:38:05 +0000

What are aluminum polymer capacitors? These are a solid type of capacitor that replaces the liquid electrolyte with a solid polymer material. Sometimes you might hear these capacitors called “organic aluminum.” Technically, they are still “electrolytic” capacitors. However, the colloquial term of “aluminum electrolytic” refers to the traditional wet electrolyte-based capacitors. In this video, I meet with Amelia Dalton of EE Journal, and we discuss these capacitor types. Mouser and EE Journal developed the video in joint with KEMET. (Previously I talked on Amelia’s Chalk Talk about SSD Capacitors.)

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Voltage Dividers as Regulators?! | AddOhms #22

Mon, 16 Oct 2017 13:00:15 +0000

Can you use voltage dividers as regulators? What if you add a Zener Diode? In this AddOhms episode, I show what happens when you try to power a complex circuit like an ESP8266 with a voltage divider instead of a regulator. (Spoiler: Get a voltage regulator.) This video tutorial is related to a write up I did recently on Zener Diodes. For questions or comments visit the AddOhms Discussion Forum. Behind the scenes A significant change for this AddOhms Episode is that I moved from Final Cut Pro X to Premiere Pro. I also shot the entire video in 4K, even though the output is 1080p. Animations were still done as 1080p compositions. One snag I ran into, the color corrections I applied in PPro, didn’t seem to get exported. You might notice when the breadboard is on screen, it has a very slight yellow tint to it.

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Op Amp Circuits by Bob Pease

Wed, 27 Sep 2017 17:45:07 +0000

Op amps are one of the most versatile ICs in electronics. A purely analog device, they can be used for amplification, summing, integration, and a whole host of other circuits. AN-31 from Texas Instruments is 32 pages of op amp circuits. (Note: this document was created before TI acquired National Semiconductor.) Even more amazing is that the author is Bob Pease. If you never heard of Mr. Pease, please spend a few minutes right now reading this TI page dedicated to him. His contributions to electronics are nearly immeasurable. (Sadly, he was involved in a car accident after attending the funeral of his equally famous engineering friend, Jim Williams.)

Zener diode makes for a lousy regulator

Wed, 20 Sep 2017 12:57:08 +0000

The Zener diode is often used to create a reference voltage. In tutorials and even college texts, there are mentions of creating a Zener diode based regulator. The idea is that the Zener maintains a known voltage drop. The problem is that current matters. This post looks a quick Zener diode overview and shows what happened when I tried to power a microcontroller using a “Zener diode regulator.” Zener diodes overview Just a brief overview if you are not familiar with Zener diodes. Like typical diodes, Zeners have low forward voltages. Typically you voltages are around 0.7. However, different material sets can offer different forward voltages.

Why ceramic capacitors change capacitance

Fri, 06 Jan 2017 23:18:03 +0000

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.

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They're JUST Capacitors?

Wed, 08 Jun 2016 00:20:22 +0000

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.

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Switching Voltage Regulator Tutorial

Wed, 13 Apr 2016 13:00:04 +0000

A switching voltage regulator is one of my favorite circuits. In school, they were the first circuits I built where I understood how transistors worked. In fact, they were the first circuit I saw an inductor being useful! Switching regulators are incredibly efficient when designed properly. Of course, this detail about design is important. They are not as simple as a linear regulator, which is basically an IC and two caps.

Cool learning resource: KEMET Engineering Center

Wed, 16 Sep 2015 13:00:21 +0000

Whether you are an engineer with enough experience to be called a graybeard or a novice that keeps grabbing the wrong end of a soldering iron, there is one component that eludes everyone working in electronics. It’s the humble capacitor. A seemingly simple device, turns out, to be incredibly complex. While the basic electrode-dielectric-electrode structure sounds simple, the materials used in that structure drastically changes the characteristics of the device. KEMET Engineering Center Screenshot, Courtesy of KEMET Corporation.

P-Channel MOSFET Tutorial with only Positive Voltages

Thu, 09 Jul 2015 01:20:55 +0000

On every page of my blog, you might notice a chat window. If I’m not busy, we can chat in real-time. If not, the messages come to me by email. Here’s one I got from Matt the other day: Let’s talk a bit about how (and why) you would use a P-Channel MOSFET. Matt, and he’s not the only one, is probably asking this question based on the “myth” that P-Channel MOSFETs require “negative voltage” supplies.

Can a 1µF decoupling capacitor be too much?

Wed, 01 Apr 2015 14:06:12 +0000

To save time, breadboard pins or just lack of knowledge people try to skip adding even one decoupling capacitor to a circuit. Either on IRC or in Forums you can almost always see it coming: “randomly, my circuit stops working” And then, “what do you mean a decoupling capacitor?” question. While working on breadboard Arduino, I came across some unexpected measurements. Initially, the only capacitors on the breadboard were the two 22pF from crystal to ground and the capacitor connected to RESET for Auto-RESET.

How does a transistor work by Veritasium

Fri, 26 Dec 2014 16:05:17 +0000

One of the best ways to describe a transistor is as an “electronic switch.” They are solid state devices that make up almost everything in our world. This video by Veritasium, which is a bit older, covers how n and p-type transistors actually work. This complements the Addohms videos on BJTs and MOSFETs, which are more about how to use them.

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The 4 best transistors to keep in your parts kit

Mon, 21 Apr 2014 15:00:38 +0000

When your project needs a transistor, there are tons of choices. Which makes answering the question “Which transistor should I use or buy?” a daunting task. Fear not, before wading through spec sheet after spec sheet, consider one of these four general purpose transistors. Every electronics enginerd’s toolbox should have a few of each. Transistors are one of the most versatile discrete components in electronics. In digital circuits, they switch on and off while in analog circuits they are used to amplify signals. For most projects, they are used to turn on a load that would kill the I/O pin of a microcontroller or microprocessor. For most circuits either a BJT or MOSFET can be used, depending on the load current you need to switch.

AddOhms #8: LEDs and Current Limiting Resistors

Mon, 10 Feb 2014 12:00:49 +0000

The idea for AddOhms #8 has been around for quite some time. I’m always trying to find ways to explain why current limiting resistors are necessary. So while working in the shop one day, I decided to play with some LEDs and a bench-power supply. Then I decided to record what happens.

Electronics: Introduction to Breadboards

Wed, 18 Dec 2013 23:32:05 +0000

Soldering every circuit you build probably isn’t practical. At some point you are probably going to want to use some type of temporary method to connect different components together. One of the popular methods is using a breadboard. This simple (and cool) looking device only needs a few instructions before you can begin Layout of a Breadboard There are various colors, shapes, and sizes that breadboards come in. However, they all generally look about the same and have the same basic functionality. The board shown in Picture 1 is a pretty common “medium” sized breadboard.

Ouch. The Arduino GSM shield has a pretty serious design flaw, with its capacitors.

Sat, 14 Sep 2013 02:44:39 +0000

Tantalum is a really misunderstood capacitor. Well, all capacitors are misunderstood, but that’s a subject for another post. I ran across this post on the Arduino forums on the Arduino GSM shield. In the post, ddewaele, reports that the shield blew up, catching fire. At first some might think it was due to abuse by the user. While it is possible that reversing the polarity or applying over-voltage could cause a catastrophic failure, it is also possible that the user doing nothing wrong could result in the same failure mode!

Voltage Regulator Tutorial and Basics

Sat, 06 Oct 2012 20:41:30 +0000

Regulator Types Fundamentally there are two types of voltage regulators: linear and switching. The names come from how they operate and how they achieve voltage regulation. Linear regulators tend to be a little cheaper to implement, but they aren’t as efficient as their more complex switching variants. There are also some “cheap and dirty” methods that some designs use. Below is a brief description and example of each. Linear A simple way to think of a linear regulator is to think of it as an active series resistor. It will vary its effective resistance so that the output voltage remains the same. The upside to such a design is that it is cheap, simple to implement, and provides a relatively clean output. The downside is that the regulator dissipates a relatively large amount of power.

LED Tutorial - Learn the basics

Wed, 21 Dec 2011 03:13:39 +0000

Nearly every consumer device makes use of the Light Emitting Diode (LED). This highly versatile device offers an easy way to add an indicator to any project while drawing a relatively small amount of current. Once their operation is understood, adding them to any project is a simple task. This tutorial is a simplified explanation of how a LED works and how to select a current limiting resistor. The LED tutorial here is enough to use LEDs in a project but is not intended to be a thorough explanation.