Electricity & electronics - Robotics, learn by building

In response to numerous questions about circuit boards available around the world, I explain the more common boards you'll find and how to use them.

Let's start from zero: Just what IS electricity and electronics anyway? We'll discuss electrical safety and DC electricity.

Let's now move on to AC electricity and how it's different than DC. We'll talk more about electrical safety as well as AC voltages tend to be far higher than DC.

We take a short segue to hopefully stem some confusion about AC and DC currents.

Continuing to learn the basics of voltage/resistance/current, we'll now show what Ohm's law is (along with really bad puns), how to use it and easily remember it.

Student's requested a short lesson on how to use the multimeter. So, here it is!

So what good is a "resistor" anyway? And what happens if we hook them up in different ways? We find out in this lesson.

Schematic diagrams are simply drawings which are like blueprints for electrical/electronic circuits. Here we start learning the basics of schematic drawings so we can build a circuit from any schematic we can get.

Variable resistors are a very useful part, but are mysterious in how they work. in this lesson we remove the mystery by opening one up and then making one for ourselves from scratch.

What is a capacitor? We remove the mystery by actually scratch-making one for use later on in a circuit, and then discuss just how these very simple components work.

In this lesson we are introduced to our very first semiconductor, the diode. We then move on to Light Emitting Diodes which are now extremely common.

Give your new found knowledge a run for its money. Test your knowledge with this quiz.

In this lesson we remove the mystery of the "breadboard" which is an actual, professional tool used by electronics engineers to design and prototype electronic circuits. We actually crack one open so you can see how they work, and then use one to build up our first simple circuit.

In this lesson we take a look at an annoying and surprisingly common problem with breadboards. We then look at the solution to the problem.

Now that we've used a breadboard, we'll get introduced to our first microchip and put it to use in making a simple, flashing LED circuit with the ever popular 555 timer microchip.

Uh oh! Our 555 timer circuit didn't work! Why not? This is common when building circuits, so let's go through the troubleshooting list to see if we can figure out what happened.

In this lesson, I explain the answer to a frequently asked question regarding calculating the resistor value when used as a current limiter for diodes.

Using the 555 timer and breadboard, we'll make a tone generator and discuss the theory behind what it's doing.

Using the circuit we built in the previous lesson, we'll now put our scratch-made electronic components to use, using them in an actual circuit.

Soldering electronic circuits is a bit of an art. A little bit of knowledge and practice will go a long way in helping you to make permanent, good quality electronic circuits.

Voltage dividers are a simple, yet essential part of electronic circuits. In this lesson we learn what a voltage divider is, where it's used and why, and then built a Voltage Controlled Oscillator (VCO) which has a miriad of uses. Please note: April 2018, an error was pointed out to me. In the original video lesson and in the original schematics, I had written that an increase in voltage on pin 5 increased the frequency. This is wrong. An increase in the voltage decreases the frequency and a decrease in voltage increases the frequency. I have updated the downloadable schematics with the correction.

VCO's are very versatile, and we'll make use of one here to make a police car siren circuit.

In this lesson we'll learn what an inductor is by first making one. We'll then learn where we find them, how they work and learn of some of the things we have to watch out for when we use one.

Now that we've learned a raft of simple electronic components, we want to be careful not to inadvertently destroy them. In this lesson we learn about how they are rated and why, and how to protect them from damage.

Switches and relays may seem simple at first, but when you pick up a simple switch that has 8 wires coming out of the back of it, it suddenly doesn't seem so simple anymore. They are, and in this lesson we learn the different types of switches and relays and how to use them. We then build an LED flasher and relay control circuit to use our relay.

In this lesson we learn first of all what a transistor is and how to use it for switching, followed by building a circuit which switches with a transistor.

You've probably heard the term "heat sink" and may not even understand what it is. This lesson explains this very simple, but important part.

In robotics, MOSFET transistors are very useful. They operate very different from bipolar transistors and so in this lesson we learn how to use them, and then put that knowledge to use by building a circuit with them.

Pulse Width Modulation (PWM) is a very versatile and effective way of controlling motors and lights by altering the electrical signal. It's also used in a few other, not-so-obvious ways like controlling servo motors. Here we learn what PWM is, and build a circuit to speed control a DC motor.  Please note: I actually made a mistake in the circuit build for the filming. For some mysterious reason, the circuit worked anyway!  So the downloadable schematic for the circuit is correct.  I also made an alteration to the original circuit: R5, a 4.7k resistor was swapped out for a 3.3k resistor to remove those beat notes I referred to in the video lesson.

Hobby Servo motors are the roboticist's best friend. Cheap and readily available, they are super simple to use BUT, require a pretty sophisticated circuit to control them. Here we use a PWM circuit specifically designed for controlling servo motors, and hook it up to a servo motor.

Taking a servo control circuit a step further, we use some of our variable resistors - like a temperature controlled resistor, to control a servo motor. Useful in things like environmental control and automated/robotic systems.

In robotics, we use electric motors incessantly. But, even small DC motors take a surprising amount of power. In this lesson we learn how to control the direction of a motor using an "H-Bridge".

Student feedback showed a surprisingly strong interest in very high power control, like mobile tank robots and electric cars. In this lesson we'll learn what doesn't work, and what does work for controlling very large power with many MOSFET transistors.

In a previous lesson we learned how to control a hobby servo motor. In this lesson we'll get into the guts of a servo motor to see exactly how they work and so be able to figure out how to build our own of any size we want.

In this lesson we actually take apart a hobby servo motor and show how it can be hacked into a speed controlled, reversible drive motor for robots.

Alright, let's run your newfound knowledge through its paces over what you've learned in this last section.

In this lesson we learn about power supplies which provide multiple power sources, and explain in detail this mysterious "ground" connection we always hear about.

Previously we used transistors for switching. Amplifying with transistors is much more tricky, and we discuss the theory behind simple transistor amplifiers.

Learning more about transistor amplifiers, we look at dual-supply amps and show what the "perfect" amplifier would be and why.

After learning about the "perfect" amplifier, we now introduce the closest thing to the perfect amplifier: the Operational Amplifier. Op Amps are very versatile and we're going to use them for very sophisticated jobs in robotics.

The LM386 is a microchip, a type of Op Amp with a high power output for audio circuits. Dead simple to use, we go over multiple, simple circuits we can build to make use of this chip.

After discussing what "bionics" is, we dive into this exciting field of robotics which is a melding of the human and robot. We start by making our own homemade sensors for reading signals from the human muscle.

In order to effectively read the extremely small electrical signals from human muscles, we'll need to use differential and instrumentation amplifiers. This lesson shows just what those are, why and how they work.

The bionic servo circuit is large and complicated. This lesson is devoted to troubleshooting potential problems in your circuit.

Op Amps generally require dual power supplies. Sometimes you just don't have one. So let's talk about how and when you can use a single power supply.

This fun project uses op amps to listen to the sounds in the room, and light up different coloured LED's according to the frequency of sound. A little dance-party light.

Red-Green-Blue (RGB) LED's are very common now and quite useful. We experiment with one in this lesson.

Electronics involving light are common and fun. Here we learn what optoelectronics are and how to use them.

A special kind of diode, the zener is useful in power supplies and some scientific research. Here we learn what they are and how to use them.

Before we look at building our own power supplies, we'll look at getting parts for those power supplies by scavenging from scrap electronics. This presents a great way to get FREE electronic parts.

No, we're not talking about autobots (even though this is a robotics course). The lowly transformer has a miriad of uses, but especially in power supplies. Here we learn what they are and how to calculate their output.

In this lesson we'll learn about a modification to transformers called the center tap. We'll also learn how all of this fits together in household power systems.

Some students may have already experimented with converting AC to DC and discovered that the voltages are quite different. In this lesson, we explain why, and how to calculate what the voltages will be.

In this lesson we'll go over the basics of building power supplies, including using voltage regulators. We then briefly discuss where you can get pre-built power supplies, often for dirt cheap or free.

In robotics, we'll often have to deal with high power, like drive motor power and electric vehicle power. In this lesson we discuss why the electrical grid boosts their voltages so high and directly relate it to the design and construction of our robotic systems.

At the request of many students, this lesson explains how to calculate resistor and capacitor values on 555 timer circuits, and how to customize the chip to get it to do what you want.

In this bonus lesson, we look at the RC constant (Resistor-Capacitor constant), what it is and where we might use it. Oh, we also cover the maths. We then take a look at using capacitors (and in particular, supercapacitors) as power supplies. This is an area of research for use in devices such as cellular phones because of the incredible charge rates of capacitors over batteries.

In response to a couple of student questions, we'll explore the world of comparators and their use in robotics.

In this bonus lesson, we examine what hysteresis is and one practical application to modern robotics