Designing a simple Electronic Timer Circuit
using Crocodile Clips Software
•
Log-on to your computer
•
Open up DT File
• To install Crocodile Technology on your computer screen,
Click-on Crocodile Technology to open software
Tool Bar with five different component
libraries
• Analogue electronic components
• Electronic Picture components
• Digital electronic components
• Mechanical and
Electro-Mechanical components
• Flow chart components
Assembling your timer circuit
• From the components toolbar, click-on Analogue Components
• On the analogue toolbar, move the cursor along each window until the words
Analogue Integrated Components appears. Click-on this window
• The tool bar will have changed showing two components. One will show the
numbers 555 in the middle. Click-on this window
• The tool bar will have changed showing four different arrangements for the
component 555. Click-on the first and hold whilst dragging it onto the blank
screen area. Place it in the middle by releasing the mouse button.
• Well done, you have now placed your first electronic
component in position.
If you have not placed the
component in the correct position,
click-on the component again and
relocate by dragging and releasing
in new position
Deleting unwanted components
Deleting components
• Components can be
removed by
selecting and
pressing delete on
your keyboard
• Or you can select
the Crocodile on
the menu bar and
move it towards the
component and
when its jaw opens
on the chosen
component, click to
see it EAT it up!
Adding Picture Components
• Click-on the Picture Components on the Components Toolbar
• The toolbar above will now have changed to show Pictures of
the actual components.
• Move along the components and select a Resistor
and drag it on to the screen area and place in the position
shown. Repeat this for the second resistor.
Your screen area should now look like this
• Again from the Picture Components select another
Resistor
and drag it onto the screen area, place it to the right
of the 555 Timer and connect it to the line marked
with a number 3.
• Next select a coloured LED of your choice and
connect it to the last Resistor placed.
Your screen area should now look like this
• Again from the Picture Component toolbar, select a Red Push
Switch and drag carefully into the position shown.
• Return to the Analogue Electronic Components toolbar
and move along the tool bar windows until the cursor
indicates Passive Components and select.
• The tool bar will change to another selection of
components. Move the cursor along the row of
components until you find Electrolytic Capacitors and
select.
• The tool bar will change again showing a selection of
capacitors. Select an Electrolytic Capacitor with the
plus sign at the top and drag carefully into position to
the left of the switch.
Your screen area should now look like this
The value of the
capacitor can be
changed by selecting
the capacitor and
altering the figures in
this box
• Return to the Picture Components tool bar and
select a 9V Battery,
drag into position below the two resistors. The top
of the battery is also below the capacitor and red
push switch previously located.
• All the components for the circuit have now
been selected for connecting together in the
circuit.
Your screen area should now look like this
Battery position guidelines
Making Circuit Connections
• The first components to be connected together are the two resistors and
the battery.
• Move the mouse cursor until it touches the positive battery terminal
and press the Select on the mouse.
• The arrow cursor will change to a symbol which looks like a roll of
tape. Keeping the button pressed, drag the ‘Roll of Tape’ towards the
resistor until it touches the end of the wire and the tape changes to a
dot. This indicates it has made the connection successfully.
• Release the select button and the line drawn should remain in position.
• Try to repeat this procedure for other connections.
• To change directions using the connecting wire can be achieved
automatically by simply moving the mouse at right angles.
Connections continued:• Should a circle appear with a line across it, when you
try to make a connection, this means it is not a suitable
connecting position and you will need to select another
position.
• Connecting wires should not be dragged across
components, otherwise a connection will not be
permitted and the connection cannot be made.
• Have a try to see if you can make all the remaining
connections illustrated until the final diagram.
Replacing Damaged Components
• When the final connections are being made, it is possible some of
the components will appear to BLOW-UP!
• Do not worry, continue with all the connections until they are
complete.
• To replace the damaged components, simply select the component
using mouse select, the component will appear with a dotted line
border, press the delete key. Alternatively you can eat it up with
the crocodile.
• A decision box will appear, asking if you wish to replace the
damaged component, click yes. The component will repair itself.
Your final screen area should look like this
Operating the Timer Circuit
• Once the circuit is complete, CHECK that all the
connections and component values are correct.
• To operate the timer circuit, simply move the mouse
cursor to the Red Switch Button and click on the Red
Top on the switch.
• The button will appear to be pressed in and the Red
LED will light up for a period of time and then stop.
• Repeat this operation and notice what is occurring to
each side of the capacitor. What do you think is
happening to the Capacitor?
• How can the time period the LED is lit, be altered to
operate for a longer/shorter period?
Final Circuit with LED Illuminated
You have now completed designing your first electronic
circuit using
Electronic Communications Technology
ECT
There are many software packages available which can
used to help learn about designing, modelling,
programming, computer control and making interesting
electronic products.
Learning about Electronics is exciting and using ECT can
make it more fun than reading books.