Bimmerboy
Flashlight Enthusiast
I'm planning an upcoming LED lantern mod, and while I can certainly choose a driver myself, I could use help in picking out the most ideal one in terms of efficiency for the power source, and LED being used. Here are the details.
The lantern is an old, fairly ugly, plastic (red, white, and black), no-name incan thing, and uses large PR base bulbs (not for long... muahh ha ha haaaa). The emitter is a Cree P4, and the power source is a 4D series battery holder, sized and shaped as a direct replacement for a 6V lantern battery. This particular item is fantastic, as with the use of dummy cells, it will let me choose anywhere from 1.5 - 6V, obviously in 1.5V increments. The springs and other metal parts look quite beefy, with excellent connections all around, and looks like it would easily handle 4 Li-ion in series.
Anyway, the goal is to make a fully variable light that goes from very dim to very bright, and is capable of extreme runtime when turned down. As mentioned, I'm using the Cree P4, so I'm wondering if 4.5V allows for better efficiency because of the closer match to emitter Vf, or if 6V is better since I could really run the alky cells totally bone dry? Also, I'd prefer current control over PWM, but it's not absolutely imperative.
So far, I think a buck circuit is what I need, but would a boost design be better, running 1.5 - 3V? Probably not, but it's worth asking to make sure. Given the variable aspect, I'm thinking about a George's80 board, but am open to all suggestions.
This is where I begin to not have much of a clue. Learning a lot more electrical theory is one of my upcoming agendas, but in the meantime, what would be my ideal driver?
Edit: It does NOT have to be very small. I've got some pretty decent space to work with inside the bulb pedestal/lampshade holder.
The lantern is an old, fairly ugly, plastic (red, white, and black), no-name incan thing, and uses large PR base bulbs (not for long... muahh ha ha haaaa). The emitter is a Cree P4, and the power source is a 4D series battery holder, sized and shaped as a direct replacement for a 6V lantern battery. This particular item is fantastic, as with the use of dummy cells, it will let me choose anywhere from 1.5 - 6V, obviously in 1.5V increments. The springs and other metal parts look quite beefy, with excellent connections all around, and looks like it would easily handle 4 Li-ion in series.
Anyway, the goal is to make a fully variable light that goes from very dim to very bright, and is capable of extreme runtime when turned down. As mentioned, I'm using the Cree P4, so I'm wondering if 4.5V allows for better efficiency because of the closer match to emitter Vf, or if 6V is better since I could really run the alky cells totally bone dry? Also, I'd prefer current control over PWM, but it's not absolutely imperative.
So far, I think a buck circuit is what I need, but would a boost design be better, running 1.5 - 3V? Probably not, but it's worth asking to make sure. Given the variable aspect, I'm thinking about a George's80 board, but am open to all suggestions.
This is where I begin to not have much of a clue. Learning a lot more electrical theory is one of my upcoming agendas, but in the meantime, what would be my ideal driver?
Edit: It does NOT have to be very small. I've got some pretty decent space to work with inside the bulb pedestal/lampshade holder.
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