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The 555 Fan
1 The PCB build
- In this project you're going to build a desktop-fan, whose speed can be controlled using a component called a potentiometer.
- The circuit uses a 555 timer chip to control the fan.
- You've had plenty of experience of soldering PCBs by now, so minimal guidance has been provided. However, putting together the actual fan takes time, so you are better off starting early.
- Here is the board you will be soldering together.
- First, you need to add the rectifier Diodes. Make sure you put them the correct way around, you can also add the 3 resistors.
- Next add the 2 ceramic capacitors. Be careful, there are 2 values 10nF (103) and 100nF (104).
- You can also add the TIP122 transistor. Make sure this is the correct way around.
- You need to now cut 2 sets of red and black wires.
- 130mm (13cm) for the motor.
- 60mm (6cm) for the switch.
- These can now be soldered to the motor and the switch. Please note how the wires are soldered in a particular direction on the motor.
- The wires for the motor can now be fed through the housing and then soldered to the PCB.
- Make sure they go through the strain relief hole.
- You can now solder the switch to the PCB.
- Again, make sure you use the strain relief hole.
- Finally, add the Potentiometer to the PCB and it is now ready to go into the housing.
- Take photos of the solder and component side of your board, and the leads to your switch. Your badge will be awarded according to the quality of your work.
- Now it is time to test your board.