1. A 555 TIMER PROJECT FOR KS3/4 DEVELOPED BY WWW.AJBOX.CO.UK FOR WWW.NELC.NET 2010

2. An electronic circuit A way to make things move A variation of a 555 Astable circuit The core of an Art project A way of developing electronic assembly skills

3. Battery powers the circuit and a motor 555 chip controls the charge on a Capacitor When Capacitor voltage is low (3 volts), 555 switches so the Capacitor charges up When Capacitor power is high (6 volts), 555 switches so the Capacitor Discharges Length of time to charge and discharge Capacitor is set by a couple of variable resistors

4. 555 chip uses the capacitor charge to decide when to switch its output pin (3) on When Capacitor is CHARGING, output pin 3 ‘sources’ current, lighting the RED LED When Capacitor is DISCHARGING, output pin 3 ‘sinks’ current, lighting the Green LED AND turning the motor

6. In the FULL version, everything is joined to a single circuit board including the battery and motor In the CIRCUIT Version, only the Main components Are ‘Onboard’

8. This view shows the full PCB as it would appear if made industrially Notice it has a white ‘silkscreen’ layer to show where components are to go It also has holes and cut-outs to hold components and fix the motor in place, these would be drilled and cut by robots These PCB’s are expensive to make in small quantities

9. This view shows the ‘mask’ layer It is used to create the copper tracks that carry the electricity round the circuit The final copper tracked PCB can be created by chemical etching or cutting processes, from this mask All black areas on the mask will end up as copper areas so it is important to get it EXACTLY right

10. Keep your Mobile lightweight and balanced Dangler has low power so will not turn heavy objects Think about using shapes and colours that look very different from varying angles Sharp mobiles are a Health and Safety risk

11. This is the last slide of this presentation about the Dangler project Lots more details are included in the worksheets, videos and guides accompanying it Please go to www.nelc.net for a free copy of this projects files DESIGNED, DEVELOPED AND PRODUCED BY WWW.AJBOOKER.CO.UK FOR NELC - 2010WWW.AJBOOKER.CO.UK