This series of videos will introduce the total beginner to basic electricity and then electronics involved in robot building.
The simple difference between the two terms electricity and electronics is that electricty and electrical circuits have no decision making capability unlike electronics and electronics circuits which do.
You talk about electricity when you are talking about the wiring in your house (for at least before smarter houses) and you flip a switch and power goes the wires and the basic circuit to turn on the lightbulb. Whereas when you talk about electronics then you may be talking about the sensors and relays inside your car that work with the various circuits in there or maybe you are talking about your television and your smart phone and the electronics inside of it.
Another way to define the difference is to talk about energy forms.
One could say that electricity or electrical devices simply “convert” the electric energy into another form of energy like a light bulb, heat or a noise. Electronic devices are more about “controlling” the flow of electrons for some job to be done.
A basic understanding of electricity will cover things like the flow of electricity thru from a battery aand thru a circuit. We will cover the positive and negative side of a battery and how electricity can go through both serial and parallel circuits to do something like turn on a light with a switch or start a motor.
Terms like current, voltage, amps will be explained using some great training kits.
We will then explain what goes on with electronics when we talk about diodes and transistors and semi conductors and integrated circuits etc.
So basically it all starts with tiny microscopic things called atoms and the fact that electrons which carry a negative charge spin around them and are able to go around a circuit from one end of a battery through to the other.
So we quickly define current and voltage like this.
Current is the flow of electrons in one direction and voltage is the pressure or force that moves the electrons around the circuit.
Electrons will flow from the negative voltage end of a battery through to the postiive side and that is the current.
Metal is a type of conductor which means it makes it easy for the electrons to flow and to slow them down or stop them you have resistors like the plastic around the wires which stop electrons from going through or electric devices that you place in a circuit to block some current called resistors.
Now we will have two kinds of voltage the battery type DC (direct current) which is just about perfectly safe to work on with robots and the AC (alternating current) the kind which involves plugging into the wall and this kind could kill you.
We just need to know the basics to start working with robots as long as we stay with DC power.
We need to understand enough about small batteres like 1.5 volt $2 dollar store batteries as compared to lipo lithium polymer batteries and what kind of power is used with Arduino boards and whatever types of servos will be needed and what separate batteries will be powering them.
You will soon start learning about the low voltages with your arduino and you will hear about different voltages being applied to large servo motors and linear actuators used to move heavy 3 foot legs on a life sized robot.
So start slow with toy sized robots and gradually the ability to power your battery for large robots will make more sense.
Lets swing now more into the topic of electronics and the parts like diodes, transistors, bridges, integrated circuits and the topics of breadboards and pinouts and the parts of the servos that we will deal with like the PWM (pulse width modulation).
The two main types of electronic circuits are called conventional and integrated.
The conventional circuit will have electronic components attached (with solder) to a PCB (printed circuit board) and an integrated circuit is a tiny chip with components on it that can go onto a conventional circuit.
When we open up a robotic like toy such as a Furby or a Robosapien we will not see an Arduino microcontroller in there but we will see one or more printed circuit boards inside and maybe an IC chip if the toy is quite advanced.
Of course there will be a certain number of sensors in there as well along with diodes, transistors, bridges, resistors, power supply, a speaker with microphone.
The Furby and most toys like this will make sounds when the sensors are activate and you wonder how that happens.
Well….its sort of complicated but basically the manufacturer makes a custom circuit board with specialially designed circuits on it.
Some cheaper toys like Halloween dancing Santas have a circuit which has prerecorded sound modules built into its circuit board. The sensors trigger the toy to start playing the sound files and with more modern toys or with Arduinos doing the controlling, you are able to make your own sounds or even attach up to the cloud and take advantage of text to speech or artificial speech.
Now if you search around the internet where they have hacked open the Furby you will learn what seems to be the electronics components inside….
It uses a common speech chip for toys from Texas Instrument called the TI50C04 and a main ic circuit board and a daughterboard circuit board and an EEPROM etc
Back in the 1980s everyone in the hacker community was talking about burning their own EPROMS and were working with game machines and toys etc. It was basically a way to put code onto a smaller chip and there were devices called Eprom burners.
Many say that the main board on a 1998 Furby is a SPC81a but that is not confirmed or really important at this point.
So we move on and define a few more terms like a diode which prevents current from flowing in one direction and is considered a switching device.
They are used as switches and also what is called a rectifier which is used to convert ac current to dc current.
Transistors are used to amplify a signal or switch a circuit on and off. We could talk about p and n junctions but that gets too complicated for right now.
There are several types of transistors including the FET field effect transistor.
Now 3 types of passive components are resistors, capacitors and inductors.
Resistors reduce the amount of current flowing through a circuit and an inductor and capacitors store energy.
Often an older electronic toy or electronic keyboard or piano doesn’t work properly because the capacitor is leaking from old age and must be replaced.
This is very common also in many older 1980s vintage computers that you might find at a yard sale or a thrift store and aren’t working at all or properly.
Now we can speed ahead and talk about digital circuits which count and compare signals and deals with everything as 0s and 1s or on and off.
We could say a few things now about components in this area like LEDs, photoelectric cells, sensors and then we get up to the topic of microcontrollers like the Arduino and its smarter cousin the full blown processor the Raspberry Pi that can run a full operating system like Linux.