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Components

Category
Components

Can a 1µF decoupling capacitor be too much?

1uF Decoupling Capacitor Circuit

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.

Keep reading to find out what happen when I added a 100nF and a 1µF cap. A bunch of scope traces and surprising results follow.

Breadboard Arduino with no Decoupling Caps
Breadboard Arduino with no Decoupling Cap
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Blog

How does a transistor work by Veritasium

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.

If you’ve never watched a Veritasium video, do yourself a favor and set aside a few minutes. He’s like the Alton Brown of science.

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Blog

The 4 best transistors to keep in your parts kit

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.

[Edit Note]  Jan (comment below) points out that there are European Equivalents that may be more available for those located in that part of the world. For NPN Check out the BC547, for PNP the BC557.

Here are some more details on each of these.

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AddOhms

AddOhms #8: LEDs and Current Limiting Resistors

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.

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Components

Electronics: Introduction to Breadboards

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

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