The Circuit


These pictures show the circuit without any components. Note the brown side is where all the components are placed through and the green side has all the copper tracks which make connection with all the components.

The copper tracks are very fragile and will come away from the circuit board if the soldering is not done carefully, if this happens then the copper needs to be “bridged” with some wire. Try to avoid this at all costs at it will make the circuit not look as good and you will lose marks for the project.

This picture shows the completed circuit board with all the components soldered on in the correct place. Make sure that you solder the correct coloured wires onto the correct places. Also make sure that all the other components are soldered in the correct way around.  If they are in the wrong place they will need to be removed, this is not a difficlt job to do but you may break the copper wired and they will need to be fixed, which is a much more difficult job to complete.

When the circuit has been completed and is working the variable resistor (VR) needs to be set to give the required time. As you can see from the photograph a small screwdriver is put into the VR and it is adjusted. The further the VR is adjusted the longer the time delay and the further to the left the shorter the tme delay. Is is necassart for you to work out youre required time and the only way to do this successfully is to adjust the VR and time the delay with a stop watch. When the required time is set then the PCB needs to be fitted into the case.

2 Responses

  1. will it be possible to change the time on the V.R. after we hav finished with the makin of this project?

    • Time can be altered by turning the variable resistor. Turning to the left reduces the time and to the right increases the time.

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