Bob, Eddie, and all,
Yes, the diode is just for reverse voltage protection, but remember
(silicon diode) there is a constant .7 volt drop across it. It is a
simple 1N4001.
There are no parts on the back of the board with the exception of the
positive wire. You can see the solder connection for it on the front.
I have posted a picture of the board at
Front http://www.citlink.net/~bjacobs1/public_html/LED/TL-1.JPG
I have posted a picture of the back of the unpopulated board at
Back http://www.citlink.net/~bjacobs1/public_html/LED/TL-2.JPG
It will be easier to see what is happening without the parts.
There are 8 resistors. They are 220 ohms, 1/4 watt.
The lamp is not real efficient as about 1/3 of the energy is used in the
resistors. The whole assemble draws 0.120 amps. This is 1.5 watts.
The resistors use 0.4 watts. I do not feel that is a problem with a 100
amp hour battery. The fix would be expensive. It would about double
the cost of the board. This would save 2/10 watts It may add to the
life expediencies of the LED's but I am not running them hard as it is.
The are operating at 1/2 rated current.
The board is 2.4 x 3 inches.
I have hung one of the boards from the crank handle on the fixture in
the Trade Wind and sat on the couch and felt the light was bright enough
for reading. That was my only "output" test.
The wiring is very simple, Plus 12 volt, diode, resistor, 3 led's, ground.
I will not go into cost or supply as maybe in the future, I may want to
sell a few of them.
I think this answers all the questions. If you have more, ask.
When I get 6 of these built and installed in the fixture and I will send
an update. It may not be as bright as the 1156's in the fixture now,
but it will supply a good amount of light and use only the 60% of power
of one bulb. 9 watts for the total fixture as opposed to about 100.
bill
25 ft Trade Wind in WV
> Hi Bill,
>
> I have a couple of bags of LEDs here that I have been playing with as
> well. Yours looks very polished. I see what looks like a diode for
> reverse voltage protection, am I right? Does each LED have a separate
> resistor with some hidden on the back?