Step 7Adding the electrolytic capacitor.

The purpose of the electrolytic capacitor is to smooth out any ripple or glitches on the power supply. The circuitry derives it's own 5V supply from the main power supply and it's useful to have a small reservoir to ride out any dips or glitches that may be caused by the switching of large loads.

This component is polarity sensitive and MUST be installed the correct way round to avoid damaging it. The PCB graphic has one side marked with a "+" symbol and the side of the capacitor with the longest lead goes to that side. The negative side of the capacitor is usually marked with a stripe with a "-" symbol on it.

Refer to the picture if in doubt.

Step 8Installing the control buttons.

There are two control buttons that are used to step through the different programs and change option settings like speed or colour.

The leads have little kinks in them which makes them a snug fit in the PCB to hold them in place while you solder them.