Meet the Modules

Most of the parts can be wired together using a screwdriver using the chocolate-block connectors. Also included are a few crocodile-clip wires that can be used to wire things up quickly to test things if you require. You will find it easier to unscrew the choc-block terminals a little to allow the end of the crocodile clip something to grip onto when you connect it.

The components are mounted on pieces of wood and you should find the following modules in the box:

Power

A Battery pack

This looks like this:

This is obviously where you get the energy to run all the circuit elements. The red wire is positive (+), the black wire is negative (-). If you use larger C-batteries, they will last longer but also included is an AA-sized battery holder. Just unclip the connector from the large holder and clip it to the smaller one if you wish to use that instead.

Switches

The main switch module contains two push buttons and a toggle switch.

This looks like this:

Pushbutton Switch

(on the switch module)

This allows current to flow as long as the button is pressed. This is exactly how a doorbell switch works. There are two pushbutton switches so you can wire them up to different things at the same time if you want.

A toggle Switch

(on the switch module)

This is like a normal light switch. It stays on until you turn it off again. This particular switch has three connections rather than two. Two terminals are connected when the switch is off and the third terminal is connected to the common one when the switch is moved to the other position. This means when the switch is in one position, one thing can be on (such as a light), and when moved to the other position, the light will go out and something else can be turned on instead.

A microswitch

This looks like this:

The microswitch can be mounted on a door or in a cupboard and you can use it to trigger an alarm when the door opens (or closes). You could use the lamps or the buzzer for this.

A Relay

This looks like this:

The relay can be used so that one circuit can switch another one. It is an electric-switch and was one of the first components used to build a computer before they invented microchips. A computer made of relays would be as big as your house so they are used for other things these days. Two of the connections are marked with the word 'coil'. If you provide power to the coil, you will hear the relay click. This is the electric switch turning on. Two of the other terminals will then connect. Turning the power to the coil off will make the relay click again and the switch will open.

A Diode

This looks like this:

A diode is like a one-way door, it allows current to flow through it one way but not the other. Diodes are used everywhere, you find them in just about every piece of electronics in your house.

Indicators

3 light-bulbs

This looks like this:

There are three bulb holders on this block and you can use either just one, or wire them up in series or parallel (more on that later). There are three bulbs included in the box. Two of these are rated at 6V, and one is 3.5V - you can see this written on the side of the bulbs. The 3.5V bulb will appear much brighter than the others but it will not last as long as the others because it is being over-driven from a 6V battery pack. It can be used safely when wiring in series (see later).

A buzzer

This looks like this:

This makes enough noise to annoy your parents so best not use this too much while they are around, use the light-bulbs instead! Note that the buzzer has one red wire and one black wire. It needs to be connected the correct way round in a circuit with red going to (+) and the black wire going to the (-) battery terminal.

A Light Emitting Diode (LED)

This looks like this:

This is the modern replacement for a light bulb. You see smaller versions of these on all sorts of electronic equipment. It needs to be connected the correct way round in a circuit because it is a diode. It is a semiconductor device so needs a little more protection than a bulb or buzzer as semiconductors can be destroyed if connected up incorrectly. You will notice a couple of other components soldered to the wires. One of these is a diode (so the LED won't be destroyed if connected the wrong way around in a circuit). The other is a resistor which limits the current flowing in the LED to a safe value to stop it being destroyed.