High-powered LED Mag-lite Conversion

Step 4 Soldering the array together

Start by placing all the LEDs through the holes in a uniform manner. I chose to place all the negative leads (flat side) on the outer ring facing outward and facing inward on the inner ring so that all the positive leads can be soldered together. Once the positives are taken care of, attach the resistors to the negative leads. In this example, the LEDs are all wired individually, since the power source is only 4.5V. For flashlights with more voltage, it may be possible to wire the LEDs in pairs, triples, etc. Cut the positive leads and one of the resistor leads to about 3/16" and solder them together. I used a wire stripper to remove pieces of insulation from the wire I had to help insulate the resistor leads from unintentional shorts. The idea here is to wire each LED with its own resistor in parallel to all the other LEDs so that they each receive the same voltage.

I've done some calculations of my own. Since batteries lose voltage over time, I decided I wanted the LEDs to be running at around 95% of their maximum when the batteries were fresh. Here are some resistor values and their corresponding voltages:

These work with the 10mm white LEDs from besthongkong:

volts LEDs ohms
4.5V 1 47
6V 1 120
9V 1 270
9V 2 91

Comments

[maxmutant1]

For a LED current limiting resistor calculator
now and in the future, you can get LED resistor values by going to:

http://home.cogeco.ca/~rpaisley4/LEDcalc.html

[silverpapermaker]

i made this sort of maglite hack before but i got one of the biggest like 2 1/2 foot 1s and fit like 14-16 bulbs in