ELECTRONICS

WHAT DOES ‘ELECTRONICS’ MEAN TO YOU ?

What are the inputs and the outputs?

Check out the inputs on this formula one race car

This is the output from this CNC machine

Hot water system

• What is the inputs and the output

What controls the temperature of the water?

What would happen if we had no control over the temperature?

Solar Hot Water system

• What controls this system?

Automatic doors

• Automatic Doors are also a system.

• What are the inputs and the outputs

Inputs?Outputs?

ELECTRONICS

• The basis of electronics is the controlled movement of electrons through a circuit, usually consisting of a power supply, circuit board, wires, and a series of components.

BATTERIES are used in a wide range of applications and come in a diverse range of size and shape

BATTERIES

Batteries provide the force to create the flow of electrons ( I, current ) in most small circuits.

(RED)(BLACK) BATTERY SYMBOL

A battery can be compared to a water pump that forces water through a pipe.

The pressure of the pump can be compared

to voltage ( V ) of a battery.

RESISTORS• Resistors reduce the

amount of current flow in a circuit, and is similar to kinking a hose - it reduces the flow of water.

• Resistor come in many different values (measured in OHMS, Ω) The higher the value the more the current flow is reduced.

RESISTORS

The coloured stripes on a resistor indicate its value

RESISTOR SYMBOL

4K7

RESISTOR COLOUR CODE

Resistors also come in a variety of sizes and types.

L.E.D (Light Emitting Diode)

L.E.D.s are used in place of small light bulbs.

They use less power, cost less, and last for 50,000 hours (approx)

L.E.D SYMBOL

• An L.E.D. is a special type of diode that gives off light. As it is a diode it only conducts electricty in one direction and it has to be inserted the right way round. (Polarity)

L.E.D (Light Emitting Diode)

The short leg is the Negative leg.

TRANSISTOR

A Tansistor is used as an amplifier or a switch.

It uses a very small current to then ‘turn on’ a larger, more useful current, which can be used to then power a light or a speaker.

C

B

ETRANSISTOR SYMBOL

Transistors also come in a variety of sizes and types.

Circuit DiagramR1 56ohm R2 10Mohm

Printed Circuit Board (PCB)

Usually a fibre- glass panel that has a copper coating. This copper coating is sreen printed and then acid etched to form tracks through which electricity can flow.

The various components and wires are inserted through the holes and soldered into place

Now its over to you

• Explain how the touch torch circuit works

• What is the control in the circuit

• Describe how the control system makes the torch better, what if it wasn’t there?

• Draw the circuit diagram using conventions

• Explain what each part is and what it does