We are living in times where data is considered the new gold, and in such a world, don’t you think there is a strong need to protect your data from theft? If you’re a corporate, many of your employees will be on travel and they would be accessing your server from different parts of the [...]
The post Why You Should Use VPN for Enhanced Security? appeared first on Electronic Circuits and Diagrams-Electronic Projects and Design.
When you start learning about circuits, you’re bound to ask “what is ground?” at one point or another. Are you actually suppose to connect your circuit into the ground??
First of all: grounding in electronics is different from grounding in high voltage electrical systems. And this article is about electronics (although I’ll mention the other case at the end).
I got an email from a reader a little while back:
«The ground symbol keeps appearing at different points in a circuit and I could not understand why a particular place was chosen for grounding. What is ground?»
Grounding something simply means connecting it to ground.
And in electronics, ground is just a name we give to a certain point in the circuit.
For example, in a circuit with one battery (with a positive and a negative terminal), we usually refer to the negative terminal as ground.
And to simplify drawing the circuit, we use a symbol.
So instead of drawing lines to all the places that should be connected to minus, you instead place the ground symbol there. This makes the circuit diagram much cleaner when there are a lot of connections to minus.
To see how the current flows in a circuit diagram with ground symbols, just connect all the points that have ground symbols. That is what you do when you build the circuit.
In some schematic diagrams, you’ll find a connection to a positive terminal, a negative terminal, and a ground terminal.
This is common in for example amplifier circuits:
So, how does this work?
In this scenario, the ground is the middle-point between the positive and the negative terminal. You can create these three voltage points by connecting two power sources in series:
Since the ground terminal is in the middle between +9V and -9V, it’s normal to call it zero volts (0V).
Click here to learn what negative voltage is.
Sometimes though, the ground term refers to an actual connection to the ground/earth. But that is usually when talking about high-voltage systems.
That’s not my field, but for the curious ones – read more here: http://en.wikipedia.org/wiki/Ground_(electricity)
Questions? Let me hear ’em in the comments below!
Copyright Build Electronic Circuits
I was first introduced to logic gates when I was around 14 years old. I had heard that computers consisted of ones and zeroes. But I didn’t understand what that really meant.
So I asked my father to explain it. And I loved his explanation because it was so simple and easy to understand. Read that article first if you’re not sure what a 1 and a 0 is yet.
Logic gates are components that we use for “doing stuff” with the 1s and 0s. You can combine them to create building blocks like flip-flops, adders, and more. Which you can use to build calculators, Arduinos, and even smartphones and computers!
Below, you’ll find an overview of the logic gates, their logic gate symbols, and how they work.
The simplest logic gate of all is the NOT gate. It takes one bit as input (A). And it gives as an output (Y) what is NOT on the input. So if there is a 1 on the input, its output is 0. And if there is 0 on the input, its output is 1. It’s also called an inverter.
| Input (A) | Output (Y) |
|---|---|
| 0 | 1 |
| 1 | 0 |
The AND gate takes two (or more) inputs and gives out a 1 if all the inputs are 1. Otherwise, it gives out a 0.
The truth table is below, but all you really need to remember is that the AND gate needs a 1 on input A and input B to give out 1.
| Input A | Input B | Output Y |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
The OR gate takes two (or more) inputs and gives out a 1 if any of the inputs are 1. Otherwise, it gives out a 0.
The truth table is below, but all you really need to remember is that the OR gate needs a 1 on input A or input B to give out 1.
| Input A | Input B | Output Y |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |
The NAND (or NOT AND) gate operates in the opposite way of the AND gate. It’s like if an AND gate had a NOT gate on its output:
| Input A | Input B | Output Y |
|---|---|---|
| 0 | 0 | 1 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
The NOR (or NOT OR) gate operates in the opposite way of the OR gate. It’s like if an OR gate had a NOT gate on its output.
| Input A | Input B | Output Y |
|---|---|---|
| 0 | 0 | 1 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 0 |
The XOR (or Exclusive OR) gate outputs 1 if its two inputs are not equal.
| Input A | Input B | Output Y |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
The XNOR (or Exclusive NOT OR) gate outputs 1 if its two inputs are equal. It basically works like an XOR gate with an inverter on the output.
| Input A | Input B | Output Y |
|---|---|---|
| 0 | 0 | 1 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
A logic gate can be built with transistors and usually comes as an Integrated Circuit (IC).
There are two classic IC series that contain a lot of the same functions; the 7400-series and the 4000-series.
The 7400-series is the oldest series. The 4000-series was introduced as a lower-power and more versatile option to the 7400. But today, several families of the 7400-series exist, some with similar properties as the 4000-series.
List of common 4000 series IC with pinouts, explanations, and example circuits
Complete list of ICs in the 4000-series
Complete list of ICs in the 7400-series
Copyright Build Electronic Circuits
I learned how to use an oscilloscope pretty much on my own. The first time I tried one, I only got some simple instructions, then I was left to myself to figure things out.
But I found that it wasn’t really that hard…
The oscilloscope can be a bit overwhelming with all its functions. But you don’t need to know every detail of it. You can actually come a long way by knowing just a few simple things.
So I want to pass those simple things on to you, so that you can start using an oscilloscope on your own.
Knowing how to use an oscilloscope is very useful when building electronic circuits. When your circuit is not working, it will help you figure out what is going on.
The oscilloscope measures voltage over time. This means that it lets you see the signal in the circuit as it changes with time.
For example if you measure the voltage to a blinking LED with an oscilloscope, you’ll see something like this:
The orange line represents the voltage. When it is on top, the voltage is high and the LED is on. And when it’s at the bottom, the voltage is low and the LED is off.
But when do you need this?
Let’s say you build a music player. But when you plug in the power, it doesn’t work. There is no sound coming…
With an oscilloscope, you can measure different points in your circuit where the sound signal should be and see if it’s actually there or not.
Something you wouldn’t be able to do with a multimeter.
This makes it much easier to debug the circuit:
First, you can measure where the sound signal enters the circuit.
No signal? Aha! Then there is a problem with the sound source.
If there is a signal there, you continue to the next part of the circuit that the sound goes through. No sound there? Well, then that part must be the problem. And so on…
A typical oscilloscope looks like this:
All these buttons are a bit intimidating right? Well, don’t worry, I’ll teach you a shortcut in just a second.
The wires you use to measure with, are named probes.
So the first thing you do, is to attach the probes to what you want to measure. The oscilloscope measures voltage. And since voltage is always measured between two points, you need to connect both the negative and positive side of the probe.
In most situations, you connect the negative probe to ground or minus in your circuit. Then connect the positive side to the thing you want to measure.
When connected, it’s time to set the oscilloscope to the right settings.
But there are sooooo many buttons! So here is a super secret (or not-so-secret) trick on how to use an oscilloscope:
Push the «Auto Set» button.
This button will analyze the signal and try to set the settings of the scope to what is best. It doesn’t always work – but in many situations it does.
What if you want to know how to use an oscilloscope without the «Auto Set» – like old-school analog oscilloscope for example?
Then, there are two main knobs to focus on:
If the signal you are looking at has large voltage swings, you need to adjust the vertical knob marked «Volts/Div» to a large Volts/Div setting. If it has very small voltage swings, you need to set it you a tiny Volts/Div setting.
If your signal is not in the screen, then scroll up or down on the vertical knob marked «Position» to find your signal.
Then use the horizontal Sec/Div knob to set the time per division on the screen. If you have a signal with really high frequency, you need a low Sec/Div setting to see it properly. If you have a very low frequency signal, you need to set it higher.
These settings are basically all you need to get started.
Now that you know how to use an oscilloscope, it’s time to get yourself one. A very good oscilloscope that’s useful for beginners, as well as more advanced circuit builders, is the Rigol DS1054Z.
If you want to save some money, look for USB oscilloscopes. These are scopes that you plug into the USB of your computer and look at the signal in some computer software.
Or you can learn how to build your own super simple Arduino oscilloscope – but keep in mind that it’s simple for a reason (it’s also pretty bad).
Do you have any questions about how to use an oscilloscope? Let me know in the comments below!
Copyright Build Electronic Circuits
