The enthusiasm towards electronics may begin with glowing an led with a battery. In this instructables I will be explaining how you can build some cool electronics testing tools and components from easily available parts. Note that these tools are for beginners. And it is intended for low voltage applications.

I will be explaining how you can build following tools/components at home

·Continuity tester using buzzer and battery.

·Polarity tester using two LEDs and a resistor.

9 volt battery clip from an old battery.

Push button using cardboard and aluminum foil

· Breadboard using cardboard ,Aluminum foil and insulation tape.

Step 1: Continuity Tester Using Buzzer and Battery

A continuity tester is used to if an electrical path can be established between two points.

. You only need the following parts to build it at home.

·A Buzzer

·A 3 Volt coin cell

·Some wires

·Insulation tape

Fig.1 shows the circuit diagram of continuity tester.

First connect wires to the buzzer terminals
Next connect -ve terminal wire of buzzer to the 3V batteries -ve terminal.And connect a wire to the +ve terminal of battery.
By using insulation tape you can join two wires to the both sides of battery.

This can be used to check the continuity of PCB tracks, wires, transformer windings, fuse, diodes, resistors etc. It uses a buzzer to give the positive indication. The simple trick is that, if the continuity exists current flows through the probes and Buzzer turns on.

Step 2: Polarity Tester Using Two LEDs and a Resistor

This simple LED tool indicates the polarity of connection. It uses a two LEDs to give two indications. If the polarity is correct, Green LED lights, and if polarity is reversed, Red LED lights.

Things required:

2 LEDs, one red led and one green led

1 k resistor (to protect LEDs)

Wires-one black and one red wire

The above figure shows circuit diagram of polarity tester.

Connect as per the circuit diagram.and you can see the result as expected .

Here we use forward and reverse bias technique of diode to check polarity .LED(light emitting diode) is a diode which operates only in forward bias.

Step 3: 9 Volt Battery Clip From an Old Battery.

It is a great idea that you can reuse a dead 9 V battery for making battery clip. Top of 9 V battery form clip for another 9V battery.

You need the following to build this:-

An old 9V battery

·2 wires

·Glue gun /gum

·Soldering iron

You can dismantle battery by using a plier or screw driver.you can start opening battery from the place where 2 end are in contact(see figure) .

You take top and down part of Battery.You can see in the figure that i have pointed out +ve and -ve polarities.

Apply solder to the clip contact(on the back side)

Solder wires to the clip contacts .

Join top and down part of battery by using glue gun.

Note:

check continuity to ensure it works.

Step 4: Push Button Using Cardboard and Aluminium Foil

A Push Button is a type of switch work on a simple mechanism called “Push-to-make”. Initially, it remains in off state or normally open state but when it is pressed, it allows the current to pass through it or we can say it makes the circuit when pressed.

You need the following to build this:

Small piece of cardboard

·Aluminium foil

·Insulation tape

·Two wires

Follow below instructions to build your own push button out of easily available parts

Get a small piece of cardboard piece
Fold it by half
Keep wires on the both side as per the above image.
Keep aluminum foil on it and cover it with insulation tape as per the above image .
You have built a simple push button out of easily available parts.

Step 5: Breadboard Using Cardboard ,Aluminium Foil and Insulation Tape.

A breadboard is a construction base for prototyping of electronics.So for a beginner it is a great tool to start with electronics .Lets see how we can build a breadboard at home with these easily available materials.

You need the following: