Measuring ESR with the PEAK ESR70 | Workbench Wednesdays Review

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There are three capacitor measurements you need to know how to make: capacitance, leakage current, and equivalent series resistance. Capacitance is easy to measure if you have a current limited supply or can use a resistor. Apply a voltage, then time how long it takes to charge-up. You might need to use an oscilloscope or even an Arduino for the second part.  Leakage current is the easiest of the three, apply a voltage (ideally through a resistor) for a few minutes, and then measure the current. ESR requires some special tricks. Since it is the resistance of the “wires” connecting to the capacitive element’s anode and code, you have to measure resistance without charging up the capacitor. (Otherwise, you get leakage.)

In the post Measuring Aluminum Electrolytic Capacitor’s ESR, I go through those methods in more detail. I also introduce the PEAK Electronics ESR70. It’s a pocket-sized instrument that measures both Capacitance and ESR. There’s a button you can touch, or it detects when a new capacitor is connected. Check out my Workbench Wednesdays review where I go into depth about how the meter works (and whether or not I like it.) Oh one bonus feature, it works while in-circuit!

As of this post, it has been almost six years since I first wrote about capacitors on my blog. The article was the Arduino GSM Shield’s capacitor has a serious design flaw. Wow, how time passes.

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Bald Engineer’s ESD Must-Haves | Workbench Wednesdays

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Electrostatic Discharge (ESD) damage can occur without you knowing it. That’s bad. However, the good news is that with little effort you can prevent it. Duratool has a kit of the most common tools for any electronics workbench. It includes a large mat, grounding cable, wrist strap, ESD-safe cleaner, and a simple electronic tester. Don’t get shocked by electrostatic discharge; add these simple tools to prevent it.

This review is on a kit that includes:

  • Large ESD Mat
  • Ground Cable
  • Wrist Strap
  • Wrist Strap Tester
  • Electrostatic Discharge Mat Cleaner

Even if you aren’t interested in ESD, you might want to watch the first 30 seconds. Hopefully, the clever thumbnail explains why. 🙂

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Tenma 72-2660 Portable Hand Held Supply | Workbench Wednesdays

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The TENMA 72-2660 portable power supply offers bench supply capability in a backpack friendly package. The single output is capable of 45 watts with up to 30 volts and 3.75 amps out. The built-in USB ports offer an easy way to power 5 Volts Arduino or Raspberry Pi projects while limiting their current. See how this portable supply performs, the things the Bald Engineer likes about it, and the points to consider before buying

This $100 power supply, model number 72-2660, is cool. It’s about the size of a digital multimeter but can output 45 Watts. Both voltage and current are adjustable. It can output up to 30 volts and 3.75 amps, but not at the same time. It does have a flaw in its design though. Fortunately, I was able to find and apply a fix for it. Overall, if you want a portable adjustable supply, this one is worth checking out.

If you are new to bench or lab power supplies, check out this bench power supply basics video.

To answer a common question: yes, I did injury my shoulder. Right before shooting the A-Roll, the parts with me on camera, I tripped. As I went to catch myself falling, I tore two of the muscles in my shoulder. It took about 6 weeks to completely heal. Yuck!

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FPC1500 Review, a Rohde & Schwarz Spectrum Analyzer

An entry level spec an with VNA features

R&S FPC1500 Review

Everyone’s first piece of test equipment should be a multimeter. Next is probably a power supply with current limiting. For many engineers, the next step is an oscilloscope. At least those working on digital electronics. Even if you are not working with RF, do not overlook a spectrum analyzer. The Rohde & Schwarz FPC1500 is three instruments in one: a Spectrum Analyzer, RF Signal Source, and a Vector Network Analyzer. In this post, I combine an FPC1500 review with an introduction to these frequency domain tools.

tl;dr; I recommend buying the FPC1500.

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I have been soldering circuits for twenty-six years. Well, except for the last 6 weeks. I have had a Weller Zero Smog EL fume extraction unit in my lab. It has changed the way I solder. When I first used it, I thought “yes, this is nice. But not a necessity.” Then the other day I didn’t feel like moving the extractor to my secondary workbench. I was immediately irritated with myself for being lazy. The smoke was so annoying. I don’t know what else changed me so quickly.

The unit under test is the Weller Zero Smog EL Fume Extraction Kit. They sent it to me in partnership with element14 as a Roadtest review. (My previous review was on the 10 MHz Picoscope.)

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picoscope 2204a on element14

Previously, I wrote up a hands-on with the PicoScope 2204A. At the time I only spent a few minutes with the device. I used it to “debug” an I2C bus between an Arduino and OLED screen. Since that initial hands-on, I’ve used the PicoScope in my lab. Most notably, I hosted another “hands-on” via an AddOhms Live Stream. I used it for another live stream where I talked about op-amps. Unfortunately, the video isn’t watchable due to some technical difficulties.

However, both of those activities plus debugging a new project I’m working on, gave me a chance to understand this humble USB-based oscilloscope. Now that I’ve held well over a month of bench time with it, I can say I am happy with the 2204A. If you’re looking for a low-cost, but fully featured oscilloscope, give the PicoScope 2204A a consideration. For more details on why I feel that way, click the button below to see my full write review on element14.

Full PicoScope 2204A Review on element14

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Aeroscope Review

Can a Bluetooth Scope replace the one on your bench?

Aeroscope Review

Previously, I reviewed the smartphone DMM, Mooshimeter. It is a great meter. One feature I didn’t spend much time on in my review was the ability to graph. Some see it as an “oscilloscope alternative.” The past couple of weeks, I’ve been using Aeroscope. It is a Bluetooth-based oscilloscope about the size of an older active probe. The Aeroscope runs $199 direct from Aeroscope Labs. The question I address in this Aeroscope review: is it better to buy this, a USB-based, or standalone scope for about the same money. How does it measure up?

My Aeroscope review looks at the specifications, the App that runs it and breaks down the key features. Let’s probe deeper.

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Test Equipment Alternatives (Suggested By You!)

Your ideas for test equipment alternatives

test equipment alternatives

A couple of weeks ago, I asked my subscribers for their favorite test equipment alternatives. The reason I asked, was because I recently picked up a Mooshimeter. It is a modern take on the multimeter. However, I will cover that in more detail soon.

While I am fortunate that my bench has the usual equipment like an adjustable power supply, oscilloscope, multimeter, and function generator, I know that not everyone else does. I also had to think back to before I had this equipment, what did I use to troubleshoot my circuits.

Sometimes when working on a project, whether hobby or professional, you just don’t have the tools you need on hand. Or worse, you cannot afford it. So here are some of the responses you all sent me.

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Benchmarking Arduino’s digitalWrite() with a Logic Analyzer

Just how fast is digitalWrite()?

digitalWrite with Logic and Arduino Uno

Recently I picked up a device called Logic from Saleae. It’s a 4-channel USB-based logic analyzer. While learning how the simple, but effective, UI works I ran some timing benchmarks on my Arduino Uno. The subject? digitalWrite(). I wanted to know how fastdigitalWrite() could turn on two (or more) pins.

Almost all Arduino users start out with the simple “blink” sketch. Turn pin 13 ON, delay, turn it OFF, and delay again. The heart of this version of “Hello World!” is the digitalWrite() function. Many Arduino users never even think about all of the stuff this single function call hides.

In this post, let’s compare the speed of digitalWrite() to direct port manipulation, using a logic analyzer.

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