PD End of Term Test

What is this?

Battery Clip

Function of Batteries

A portable power supply which is connected to the the circuit via the battery clip. Batteries contain chemicals that store energy. When connected to a circuit the chemical energy is converted into electrical energy that powers the circuit

What is this?

Hegner Saw

What is this?

G-Cramp

What is this?

LDR

What is this?

Transistor

Function of a Transitor

Simplest form of an electronic switch by allowing a small amount of current to switch a larger amount of current on or off. Has three legs: base, collector and emitter with the emitter connected to 0V

What is this?

Motor

What is this?

Push to make switch

Function of a Push Switch

A simple switch that can be on or off. When the switch is activated (pressed), the input pin is connected to the positive battery supply, providing an on signal to the microcontroller

What is this?

Piezo buzzer

Function of a Piezo Buzzer

Sounding device that produces tone and alarms/sound. Contains a piezo ceramic disc that moves up and down with voltage- movement of disc generates sound

What is this?

IC socket

Function of an IC Socket

Acts as a holder for an IC chip. Allows the safe insertion and removal of IC chips which can be damaged by heat when soldered

What is this?

IC chip

Function of an IC chip

They are microcontrollers which are purchased “blank” and then a program is written on a computer and downloaded onto the chip. Contains memory processing units and input/output pins in a single circuit. Replaces parts or even a full circuit.

What is this?

Wire strippers

What is this?

LED

Function of an LED

Gives out light and requires a small amount of current to work- more efficient than bulbs. Has a long positive leg and a short negative leg with a flat edge on the plastic casing

What is this?

Picaxe stereo download socket

Function of a Picaxe Download Socket

Allows program to be downloaded by letting the computer and the micro connector “talk”. A cable connects the USB port on computer to socket

What is this?

Resistor

Function of a Resistor

Resists the amount of current flowing through a circuit. The higher the value, the higher the resistance so less electricity is able to flow through the circuit. Used to protect components. Value given in ohms.

What is this?

Printed Circuit Board (PCB)

Function of a PCB

Mechanically supports and electrically connects electronic components using conductive tracks tracks and pads etched from copper laminated onto a non-conductive substrate. Used in all electronic product

What is this?

Steel rule

What is this?

Solder

What is this?

Belt Sander

What is this?

Pliers

What is this?

Solder extractor

What is this?

Soldering Iron

What is this?

Helping Hands

What is this?

Vice

What is this?

Cordless Electric Drill

Steps of soldering

1. Place the components in the PCB, making sure they are facing the right way.

2. Turn the soldering iron on. Allow it to warm up.

3. Clean the soldering iron in the soldering iron cleaner.

4. Put the tip of the soldering iron in the tip tinner.

5. With one hand, hold some solder at least 5cm away from your fingertips to the leg of the component.

6. Use the soldering iron to melt the solder and rotate it slightly to make a good solder joint

7. Allow it to cool

What is it called when you have too little solder?

Loose connection

What is it called when you have too much solder?

Short circuit

Wave soldering

1. Check the components are attached and add weights to hold them down

2. Place it on the conveyor belt

3. Spray it with flux so the solder adheres (sticks) to the silver pads

4. Heat it to the optimum temperature

5. A wave of molten solder attaches the components

6. It is cooled with electric fans

Reflow soldering

1. Solder paste is applied to the silver pads of the components using a stencil

2. Put the components on- the paste is sticky so they stick on and stay in place

3. Put it in an oven above the melting point of solder. The solder reflows and attaches to the components.

4. The circuit board is left to cool