LED building lighting

01/09/2006 LED building lighting
Now that I have a good understanding of LED lighting and have settled on a system to use for my building lighting I have mode up my first module to go into the Farmhouse kit I am currently building.

I have decided to go for a full rectified circuit to reduce flicker. The first module pictured here is for driving two white LEDs. It uses 4 diodes connected as a bridge rectifier and a 390 Ohm resistor. I put a bit of yellow paint on the LEDs to make the light a bit warmer

I placed the second LED on a length of wire to allow the second LED to be installed some distance from the first. I anticipate using some hot-glue to hold the mini circuit board in the base of the model.

The LEDs are 3mm in diameter and the circuit boardlett is 19mm x 13mm

Update 2006-01-29: this is the circuit schematic:

I used:
4x 1N4001 diodes
2x 3mm white LEDs 20mA-30mA 3.3V forward voltage
1x 390 Ohm resistor (2006-03-23 update: 390 Ohms is probably too small since the peak input voltage is in fact 21V in a 16VAC RMS supply. One should use at least a 500 Ohm resistor for a 30mA circuit and about 820 Ohms for 20mA)

Total cost of components: about $1.16