Step #2: Select a Power Supply
- The first thing that you need is a DC power supply (AC to DC power adapter). This will power both the LEDs and the control circuit.
- Use a power adapter with an output voltage of at least 5V. It is also helpful if the output voltage of the power supply is a multiple of the LED voltage. For example, if the LED voltage is 3V, then it is easiest to work with a power supply whose output voltage is either 6V, 9V, or 12V. But this isn't 100% necessary. If the voltage of your power adapter is not a multiple of the LED voltage, then you will need to add a series resistor to each set of LEDs wired in series.
- I am using a 12VDC 200mA power supply. But other power supplies can also work. The only difference that it will make is that a power supply with a different output rating will be able to power a different number of LEDs.
Step #9: Connect the Power Cord and the Switch to the Circuit Board
Feed the power cord into the housing of the lamp head. Then solder the wires to the appropriate place of the circuit board. Also solder the lamp switch to the appropriate place on the board. If your lamp does not have an easily accessible switch, you will need to add one. Any small latching switch will work.