ELEC
electronics primer

.:A Small Electronics Primer:.

electronic components

Electronics in Brief

No previous electronic experience is required to have fun with this kit. Here are a few details about each component to make identifying, and perhaps understanding them, a bit easier. If at any point you are worried about how a component is used or why it's not working, the internet offers a treasure trove of advice. We can also be contacted at info@robotgames.com or questions can be posted to the issues for our github repository.

Component Details

LED

(Light Emitting Diode)

image of LEDs

What it Does:

Emits light when a small current is passed through it. (only in one direction)

Identifying:

Looks like a mini light bulb.

No. of Leads:

2 (one longer, this one connects to positive)

Things to watch out for:

  • Will only work in one direction
  • Requires a current limiting resistor

More details on Wikipedia:

Diode

image of single THT diode

What it Does:

The electronic equivalent of a one way valve. Allowing current to flow in one direction but not the other.

Identifying:

Usually a cylinder with wires extending from either end. (and an off centre line indicating polarity)

No. of Leads:

2

Things to watch out for:

  • Will only work in one direction (current will flow if end with the line is connected to ground)

More details on Wikipedia:

Resistor

image of single 1/4 watt THT resistor

What it Does:

Restricts the amount of current that can flow through a circuit.

Identifying:

Cylinder with wires extending from either end. The value is displayed using a colour coding system (for details see the end of this page)

No. of Leads:

2

Things to watch out for:

  • Easy to grab the wrong value (double check the colours before using)

More details on Wikipedia:

Transistor

image of 2n2222 TO92 package BJT transistor

What it Does:

Uses a small current to switch or amplify a much larger current.

Identifying:

Comes in many different packages but you can read the part number off the package. (P2N2222AG in this kit and find a datasheet online)

No. of Leads:

3 (Base, Collector, Emitter)

Things to watch out for:

  • Plugging in the right way round (also a current limiting resistor is often needed on the base pin)

More details on Wikipedia:

Hobby Servo

example image of hobby servo

What it Does:

Takes a timed pulse and converts it into an angular position of the output shaft.

Identifying:

A plastic box with 3 wires coming out one side and a shaft with a plastic horn out the top.

No. of Leads:

3

Things to watch out for:

  • The plug is not polarized so make sure it is plugged in the right way

More details on Wikipedia:

Extra information here as well.

DC Motor

image of small dc hobby motor

What it Does:

Spins when a current is passed through it.

Identifying:

This one is easy, it looks like a motor. Usually a cylinder with a shaft coming out of one end.

No. of Leads:

2

Things to watch out for:

  • Using a transistor or relay that is rated for the size of motor you're using.

More details on Wikipedia:

Piezo Element

image of piezo buzzer

What it Does:

A pulse of current will cause it to click. A stream of pulses will cause it to emit a tone.

Identifying:

In this kit it comes in a little black barrel, but sometimes they are just a gold disc.

No. of Leads:

2

Things to watch out for:

  • Difficult to misuse

More details on Wikipedia:

IC

(Integrated Circuit)

image of a couple of IC chips

What it Does:

Combines any range of complicated electronics inside an easy to use package.

Identifying:

The part ID is written on the outside of the package. (this sometimes requires a lot of light or a magnifying glass to read).

No. of Leads:

2 - 100s (in this kit there is one with 3 (TMP36) and one with 16 (74HC595)

Things to watch out for:

  • Proper orientation. (look for marks showing pin 1)

More details on Wikipedia:

Pushbutton

image of a pushbutton switch

What it Does:

Completes a circuit when it is pressed.

Identifying:

A little square with leads out the bottom and a button on the top.

No. of Leads:

4

Things to watch out for:

  • These are almost square so can be inserted 90 degrees off angle

More details on Wikipedia:

Potentiometer

image of a potentiometer

What it Does:

Produces a variable resistance dependant on the angular position of the shaft.

Identifying:

They can be packaged in many different form factors, look for a dial to identify.

No. of Leads:

3

Things to watch out for:

  • Accidentally buying logarithmic scale

More details on Wikipedia:

Photo Resistor

(Light Dependent Resistor)

image of a light Dependent resistor

What it Does:

Produces a variable resistance dependant on the amount of incident light.

Identifying:

Usually a little disk with a clear top and a curvy line underneath.

No. of Leads:

2

Things to watch out for:

  • Remember it needs to be in a voltage divider before it provides a useful input

More details on Wikipedia:

Resistor Colour Codes

Examples:

560 ohms (560Ω)
green-blue-brown (56 x 10^1)
green-blue-black-black (560 x 10^0)
2,200 ohms (2.2kΩ)
red-red-red (22 x 10^2)
red-red-black-brown (220 x 10^1)
10,000 ohms (10kΩ)
brown-black-orange (10 x 10^3)
brown-black-black-red (100 & 10^2)
Shown without tolerance or temperature coefficient color bands Wiki resistor colour codes

Lead Clipping

Some components in this kit come with very long wire leads. To make them more compatible with a breadboard a couple of changes are required.

LEDs:

Clip the leads so the long lead is ~10mm (3/8"") long and the short one is ~7mm (9/32"").

Resistors:

Bend the leads down so they are 90 degrees to the cylinder. Then snip them so they are ~6mm (1/4"") long.

Other Components:

Other components may need clipping. Use your discretion when doing so.