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This is an easy enough circuit to build, I'll go with this one, thanks.Dave.H wrote:
I'm looking to convert a flashlight I have to LED, the flashlight uses
a 6 volt "lantern battery but the LED's max voltage rating is 3.1
volts DC. What value resistor would I need for this? I also want to
run it off a 9 volt supply, again I need to know the value of the
resistor.
The LED is part # Z4251 atwww.dse.com.au.
I didn't see a constant current solution posted, probably
because it is costs more than using just a series resistor.
But constant current was mentioned, so here's a constant
current circuit that uses 1 watt resistors and an LM317
chip, and works either 6 or 9 volts input. It provides
about 347 mA to the LED.
-----
+ ----Vin|LM317|Vout---+-----+
----- | |
Adj [3R9] [47R]
| | |
+----------+-----+ I = 347 mA
|
[LED]
|
Gnd --------------------------+
The chip needs to be installed on a heat sink. I would omit the 47
ohm resistor to reduce the current to about 320 mA. That's kinder
to the LED.
Dick Smith has the heatsink for $1.25, the LM317 for $2.10 and
the resistors for 10 cents each.
Ed
Check these out. These are current regulators for Cree high powerRed. They also have blue versions but they're about 1/3 as bright as
the red/white.
That reminded me of something I saw at www.jaycar.com.au, a similarOn Wed, 23 Jan 2008 07:06:25 -0800 (PST), "Dave.H"
the19...@googlemail.com> wrote:
Red. They also have blue versions but they're about 1/3 as bright as
the red/white.
Check these out. These are current regulators for Cree high power
leds.
http://www.dealextreme.com/details.dx/sku.3256
--
A much more sensible option.On Jan 24, 3:01 pm, default <defa...@defaulter.net> wrote:
On Wed, 23 Jan 2008 07:06:25 -0800 (PST), "Dave.H"
the19...@googlemail.com> wrote:
Red. They also have blue versions but they're about 1/3 as bright as
the red/white.
Check these out. These are current regulators for Cree high power
leds.
http://www.dealextreme.com/details.dx/sku.3256
--
That reminded me of something I saw atwww.jaycar.com.au, a similar
thing for 12-13.5 volt AC/DC input. It won't run on the 6 volt
battery,. but the Cree LED's won't fit the flashlight anyway, but I'm
getting ideas for some mood lighting using the 1 watt Cree LED's. Part
# for the regulator: AA-0583, Part # for the LED I'm thinking of
using: ZD0444
Think I might just start looking for a high quality LED flashlight,
and be done with the old one.
That flashlight is something. I will definitely give that one aOn Jan 24, 6:31 pm, "Dave.H" <the19...@googlemail.com> wrote:
On Jan 24, 3:01 pm, default <defa...@defaulter.net> wrote:
On Wed, 23 Jan 2008 07:06:25 -0800 (PST), "Dave.H"
the19...@googlemail.com> wrote:
Red. They also have blue versions but they're about 1/3 as bright as
the red/white.
Check these out. These are current regulators for Cree high power
leds.
http://www.dealextreme.com/details.dx/sku.3256
--
That reminded me of something I saw atwww.jaycar.com.au, a similar
thing for 12-13.5 volt AC/DC input. It won't run on the 6 volt
battery,. but the Cree LED's won't fit the flashlight anyway, but I'm
getting ideas for some mood lighting using the 1 watt Cree LED's. Part
# for the regulator: AA-0583, Part # for the LED I'm thinking of
using: ZD0444
Think I might just start looking for a high quality LED flashlight,
and be done with the old one.
A much more sensible option.
Make sure you get a good brand one, otherwise you'll be getting the
fake asian copy LED's which aren't anywhere near as bright as the Cree
or Luxeon. Ebay is chock full of the fake ones. When you see a 3W
Luxeon light being advertised for $5, you know it's not the real deal.
Have a look here for an excellent review site:http://www.flashlightreviews.com/
I just ordered one of these Cree ones for my bike (heaps cheaper than
an equivalent output purpose designed bike light:http://www.flashlightreviews.com/reviews/fenix_l1dce-l2dce.htm
The brightness is just insane.
I ordered from here:https://www.fenix-store.com
No problem with delivery to Oz.
Dave.
You might want to sub a low drop out regulator so it will work down toOn Jan 24, 12:05 pm, ehsjr <eh...@bellatlantic.net> wrote:
Dave.H wrote:
I'm looking to convert a flashlight I have to LED, the flashlight uses
a 6 volt "lantern battery but the LED's max voltage rating is 3.1
volts DC. What value resistor would I need for this? I also want to
run it off a 9 volt supply, again I need to know the value of the
resistor.
The LED is part # Z4251 atwww.dse.com.au.
I didn't see a constant current solution posted, probably
because it is costs more than using just a series resistor.
But constant current was mentioned, so here's a constant
current circuit that uses 1 watt resistors and an LM317
chip, and works either 6 or 9 volts input. It provides
about 347 mA to the LED.
-----
+ ----Vin|LM317|Vout---+-----+
----- | |
Adj [3R9] [47R]
| | |
+----------+-----+ I = 347 mA
|
[LED]
|
Gnd --------------------------+
The chip needs to be installed on a heat sink. I would omit the 47
ohm resistor to reduce the current to about 320 mA. That's kinder
to the LED.
Dick Smith has the heatsink for $1.25, the LM317 for $2.10 and
the resistors for 10 cents each.
Ed
This is an easy enough circuit to build, I'll go with this one, thanks.