Coleman Sentinel Mod

White LEDs

The Coleman Sentinel is a self powered light which uses the Freeplay mechanism to charge 3 AA NiMH batteries inside the case. By spinnning a crank on the side you charge the batteries. Although it works very well with its 2 filament incandescent bulb, I decided to make it "even better" by converting it to LEDs. I had 12 LEDs to work with. Originally I was going to set it up with 10 LEDs only. They would use an LM2621 booster board for "high" mode and direct drive of the LEDs for "low" mode. After a series of mishaps which destroyed all of my remaining LM2621 boards I elected (had no choice, really) to direct drive the LEDs, adding 2 to the board for the "low" setting and running the original 10 for "high". With the original bulb, 30 seconds of cranking would result in about 8 minutes of light on "low". With the LEDs, 30 seconds of cranking will result in 40 minutes on "low" which gives plenty of light to see by, and about 8 minutes on "high" which actually produces more light than the incandescent bulb on "low".

Lux and Runtime based on 30 second charge
Runtime (minutes)
Incandescent Bulb High
Incandescent Bulb Low
~ 8
LEDs High (10)
~ 8
LEDs Low (2)
~ 40


First board
Trimed and bent leads for eletrical paths
Soldered Leads together for circuitry
Test OK
Added 2 LEDs for "low" mode
Rear of board - 2 added LEDs (at picture bottom)
Trimmed board and installed

Double-face foam tape stuck down board and added glowsheeting around the array of LEDs

Low mode - 10 Lux at 1 meter

High mode - 50 lux at 1 meter

James S. also made a mod of this light, but used LED reflectors to position the LEDs directly on the lens. Hot glue was then used to fill the spaces around the LED lenses and to hold them in place. A framework was made with the LED leads and soldered together with wires plugged directly into the sockets as I did. The center 2 LEDs run on "low" and the surrounding 8 LEDs are used when switched to "high".

Thanks James!

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