LEDs in flashlights?

[DaveC]

Such as this one:

http://www.brightguy.com/detail.html?cart=1090077700192795&sku=OPA3W

how are the LEDs configured? Are they paralleled? Each with a series
resistor? Regulator?

In this application, the source is 2.4-3.0 volts, depending on type of cell.
Any idea?
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[Gareth]

DaveC wrote:

Such as this one:

http://www.brightguy.com/detail.html?cart=1090077700192795&sku=OPA3W

how are the LEDs configured? Are they paralleled? Each with a series
resistor? Regulator?

In this application, the source is 2.4-3.0 volts, depending on type of cell.
Any idea?

There are switched mode power supply ICs designed to drive white LEDs.
It could well use one of these. Certainly that would give the constant
light output they claim:

"The light output of the NewBeam LED module maintains a perfectly
constant level for almost all of the batteries' useful life"

For an example of such an IC have a look at:

http://pdfserv.maxim-ic.com/en/ds/MAX1553-MAX1554.pdf

Gareth.
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[dan]

What's that Lassie? You say that DaveC fell down the old
sci.electronics.basics mine and will die if we don't mount a rescue by
Sat, 17 Jul 2004 08:17:11 -0700:

Such as this one:

http://www.brightguy.com/detail.html?cart=1090077700192795&sku=OPA3W

how are the LEDs configured? Are they paralleled? Each with a series
resistor? Regulator?

In this application, the source is 2.4-3.0 volts, depending on type of cell.
Any idea?

They use a switching power supply. Ask about it and other LED drivers
here:
http://www.candlepowerforums.com/ubbthreads/ubbthreads.php
--

Dan

 

[Watson A.Name \"Watt Sun]

DaveC wrote:

Such as this one:

http://www.brightguy.com/detail.html?cart=1090077700192795&sku=OPA3W

how are the LEDs configured? Are they paralleled? Each with a series
resistor? Regulator?

In this application, the source is 2.4-3.0 volts, depending on type of cell.
Any idea?

I have two Opalec Newbeams installed in my mini maglites, and I use them
all the time.

The Newbeam is not focused, so turning the head of the maglite does
nothing but turn it on/off. There is a circuit encapsulated in epoxy,
so you can't see what's in the circuit. My guess is that there's a chip
in there and the three LEDs are in series. Buy one and find out.
Another model is the Techass MagmaLED which is a single LED, and it is
focusable. www.techass.com