Sometimes the hardest lessons are the ones you have to learn multiple times. When getting started with Electronics circuits, there’s a handful of things that can ruin a day (or experiment.) Here are 6 mistakes I made when I got started, and mistakes I see in the beginner classes I teach. In fairness #6 isn’t one I did starting out, because Fritzing wasn’t around. However, it took me a while to learn the value of providing a schematic, even a simple sketched out block diagram.
1. Shorting out stuff on breadboards
Breadboards are made up of groups of columns and rows. For electronics beginners, the little squares seem like a disconnected grid of, well…., little squares. If you don’t understand how these squares are connected, you might end up causing a short circuit!
2. Changing connections while powered
Here’s the #1 take away tip from this whole list:
NEVER CHANGE CONNECTIONS WHILE POWERED
By far, the easiest way to damage a circuit is to change a connection while the circuit is powered. It is way too easy to put a wire into a wrong hole or, more likely, briefly touch some exposed metal by accident. You want to know the scariest thing? You might cause damage and not even know it.
Not all damaged components fail immediately!
It is entirely possible to touch the leg of a part and cause a short circuit that lasts less than a second. You may not notice it happened, until days (or weeks) later when your circuit stops working suddenly!
3. Treating ESD sensitive devices, like they’re not
Electrostatic discharge (or ESD) is when electricity suddenly flows between two electrically charged objects. You don’t always need direct contact for a discharge to occur. The most common way for a ESD event to happen is when you touch a component. You’re probably familiar with static electricity. When you touch a metal object like a heater or door knob and feel a small shock, that’s an electrostatic discharge (ESD). If that happens when you touch an IC or component like a MOSFET, you will actually damage the component. Over time that damage will result in a failure, if the part doesn’t fail immediately. Here’s the key to remember: you don’t always feel the discharge. Not all ESD shocks that damage electronic components have enough energy for you to feel it.
Just because you don’t feel a shock, doesn’t mean you don’t cause ESD damage.
When you’re working with your circuits, consider using an ESD strap with an ESD mat. Here’s the Elenco set I use, available on amazon (affiliate link ).
4. Misusing the terms Volts, Amps, and Power
Electronics engineering is a very technical subject. Interestingly, many of the terms used, are used in everyday life. So as a hobbyist or a beginner, it might be difficult to use those terms correctly. People often mix up “voltage” and “power” when talking about electricity. For example I have heard phases similar to “USB provides 5volts of power” when referring to phone “chargers” (another mis-used term.) The simplest way I like to think about these three terms is this way:
Voltage is Pressure Current (Amps) is Flow Power is Work
What this means is that you apply some electrical pressure (Volts), current/electricity will start to flow (Current), and the heat or light generated is the work (Power). The difference between Voltage, Current, and Power is covered in this AddOhms video. By the way,
Never use the term “Amperage.”
Please, just say “Amps.”
5. Current Limiting LEDs
LEDs require current limiting. To understand more about how LEDs work, read this tutorial on LED Basics. There are tutorials on the web that say Pin 13 of Arduino boards have a built-in current limiting resistors, so you can connect a LED without a resistor. These are WRONG. While it is true there is a resistor, it is only there to limit the current for the on-board LED! Here’s another AddOhms video. This one is on LEDs and Current Limiting resistors. In it, I even show what could happen if you don’t limit the current (the LED burns out.)
Always remember to use a current limiting resistor
(or some other method) to limit current to a LED.
6. Messy Fritzing diagrams
Fritzing is an open source software project aimed at making design electronic circuits (and boards) easy. The free software runs on Windows, Mac OSX, and Linux. You can create schematics and PCBs and even breadboard diagrams. These breadboard diagrams are often used by beginners when asking questions in forums. These can be an interesting tool, except when the lay out is messy, like the left picture.
Which one is easier to follow, left or right? Even if you included the Fritzing file (which most people don’t), it’d be nearly impossible for anyone to understand what you’ve done… and provide a response!
Quick tip on how to add “bends” in Fritzing. You can’t bend a wire until after you’ve made a connection. Once you have your connection, right click on a wire and select “Add Bendpoint”. Repeat to add multiple bend points.
Also in the content menu is the ability to change the wire’s color. This is also really helpful. Keep in mind,
clean layouts aren’t limited to the virtual world.
When connecting things on an actual breadboard, keep your connections clean.
These are 6 common mistakes I see beginners making. Have you made any of these yourself? Are you still making them? Or, what other simple mistakes should be avoided?