e-learning in e-learning in ElectronicsElectronics

The Design ProcessThe Design Process Lesson 1: Circuit SimulationsLesson 1: Circuit Simulations

Crocodile clipsCrocodile clips

Lesson 2: Design DecisionsLesson 2: Design Decisions Modular circuit designModular circuit design

Lesson 3: Realising my DesignLesson 3: Realising my Design Crocodile clips + modular circuit designCrocodile clips + modular circuit design

Lesson 4: Building the PrototypeLesson 4: Building the Prototype BreadboardingBreadboarding

Lesson 5: ManufactureLesson 5: Manufacture PCB design / Automatic manufacturePCB design / Automatic manufacture

Lesson 1Lesson 1

Circuit Simulations Circuit Simulations Crocodile clipsCrocodile clips

ObjectivesObjectives AimAim

Develop a students electronics design skills though e-Develop a students electronics design skills though e-learning. learning.

Develop confidence and knowledge in the use of crocodile Develop confidence and knowledge in the use of crocodile clips.clips.

ObjectivesObjectives Construct simple circuits using crocodile clips.Construct simple circuits using crocodile clips. Make informed decisions over the choice of switches used in Make informed decisions over the choice of switches used in

electronics circuits through practical experience of their electronics circuits through practical experience of their operation.operation.

Incorporate logic gates as a means of controlling decisions within Incorporate logic gates as a means of controlling decisions within basic circuits.basic circuits.

Discover ways of monitoring circuit action using probes, on Discover ways of monitoring circuit action using probes, on screen messages and graphical images.screen messages and graphical images.

Investigate the action of Astable and Monostable clocks using the Investigate the action of Astable and Monostable clocks using the prepared circuits in the package.prepared circuits in the package.

1. Navigation and Tutorial1. Navigation and Tutorial

HTML link to HTML link to crocodile clipscrocodile clips

Crocphys.exe

The Crocodile TutorialThe Crocodile Tutorial

The 2 tutorials under Help The 2 tutorials under Help provides an effective route for provides an effective route for investigating the initial workings investigating the initial workings

of crocodileof crocodile physics.physics.

Activity 1Activity 1 Follow the Electronics tutorial. Follow the Electronics tutorial.

This will provide you with the This will provide you with the initial skills required to investigate initial skills required to investigate this package.this package.

2. Switching2. Switching

In order to provide a clean transition In order to provide a clean transition from 0 to 1 in TTL logic circuits from 0 to 1 in TTL logic circuits switches should be pulled cleanly switches should be pulled cleanly between 0V and 5V. This is done between 0V and 5V. This is done

using a pull down resistor R of 470Ωusing a pull down resistor R of 470Ω

Activity 2 – Using JU1_switchesActivity 2 – Using JU1_switchesSet the circuit with a logic monitor on Set the circuit with a logic monitor on the output, then investigate the the output, then investigate the action. action.

Extension:Extension:The circuit you have made is The circuit you have made is commonly known as a Pull Up switch.commonly known as a Pull Up switch.Try designing a pull down switch.Try designing a pull down switch.

Sketch solution opposite:-Sketch solution opposite:-

3. Logic Gates3. Logic Gates

Activity 3: Investigate the operation of the AND gate using the components provided Activity 3: Investigate the operation of the AND gate using the components provided in JU1_And, then replace the AND gate with the OR gate provided. Now try in JU1_And, then replace the AND gate with the OR gate provided. Now try completing the truth table for the OR gate below.completing the truth table for the OR gate below.

4. Output Displays – The LED array4. Output Displays – The LED array An LED normally needs a forward An LED normally needs a forward

voltage drop of 2V and sufficient voltage drop of 2V and sufficient light is emitted with 10mA. A light is emitted with 10mA. A resistor is usually added to resistor is usually added to protect the LED from damage.protect the LED from damage.

Activity 4: Find the value of the Activity 4: Find the value of the resistor needed to control the resistor needed to control the current at 10mA when the supply current at 10mA when the supply voltage is 5V. (Use JU1_LED) voltage is 5V. (Use JU1_LED)

Extension:Extension: Add an Ammeter in series with Add an Ammeter in series with

the LED, Resistor and find the the LED, Resistor and find the safe current which turns on the safe current which turns on the LED.LED.

Fill in Answer here = Fill in Answer here = Now retry this with a voltage of Now retry this with a voltage of

9V as shown opposite. What 9V as shown opposite. What protective resistor is needed in protective resistor is needed in this case?this case?

JU1_switches_NOTJU1_And_gatesJU1_LEDs

5. Monostable v Astable Clocks5. Monostable v Astable Clocks

Monostable.Monostable. A trigger pulse produces a A trigger pulse produces a

single pulse of fixed single pulse of fixed duration.duration.

AstableAstable This is a free running and This is a free running and

produces a continuous produces a continuous supply of pulses at the supply of pulses at the output.output.

Creating my First ClockCreating my First ClockActivity 5: Using the models – Examples – Electronics Examples – Oscillator 1 provided investigate the Activity 5: Using the models – Examples – Electronics Examples – Oscillator 1 provided investigate the

settings required to produce an Astable clock with a frequency of 1Hz or period of 1s. You will need settings required to produce an Astable clock with a frequency of 1Hz or period of 1s. You will need to alter the resistor that starts as 22k. Use the pulse in the graph to monitor the output frequency.to alter the resistor that starts as 22k. Use the pulse in the graph to monitor the output frequency.