Re: LED mast head light
Where did you get a circular piece of circuit board?
I though about doing the resistor bit, but I wanted the most
efficient setup I could get. With the resistor, 3/4 of the power used
in your light goes out the resistor as heat.
Plus, the voltage at the LEDs would vary from dim at low batt to
extra bright when charging from the motor.
I burned out three LEDs learning that the things want EXACTLY 3.6v,
all the time.
You could get this with a LM317, but you would still loose quite a
bit as heat.
That is why I went with a switching regulator (as Claton Cadmus
suggested), it runs at about 85% efficency.
I'm using 16 LED's, they have a 20 degree beam at 5600 mcd. I picked
the number because that was what they were using in the $125 bulbs
for masthead lights. Plus, 360/20 is 16! I may be brighter than
needed, but maybe that will keep me out of a collision.
Incidentaly, I'm running ALL the lights on my boat from the one
switching regulator. Cabin, reading, bow, stern, and masthead.
--- In bolger@y..., "Seabird Aviation Australia Pty Ltd"
<seabird@a...> wrote:
into an off-the-shelf mast head light lens. The LEDs were about $3
each the lens $7 and a resister to lower the voltage to 3.6 volts was
$1.50. The light has been operating for a year, it has a light switch
which cost about $9 to turn itself on and off, but because the
current draw is negligible when compared to a normal filament bulb I
doubt if this is needed.
I though about doing the resistor bit, but I wanted the most
efficient setup I could get. With the resistor, 3/4 of the power used
in your light goes out the resistor as heat.
Plus, the voltage at the LEDs would vary from dim at low batt to
extra bright when charging from the motor.
I burned out three LEDs learning that the things want EXACTLY 3.6v,
all the time.
You could get this with a LM317, but you would still loose quite a
bit as heat.
That is why I went with a switching regulator (as Claton Cadmus
suggested), it runs at about 85% efficency.
I'm using 16 LED's, they have a 20 degree beam at 5600 mcd. I picked
the number because that was what they were using in the $125 bulbs
for masthead lights. Plus, 360/20 is 16! I may be brighter than
needed, but maybe that will keep me out of a collision.
Incidentaly, I'm running ALL the lights on my boat from the one
switching regulator. Cabin, reading, bow, stern, and masthead.
--- In bolger@y..., "Seabird Aviation Australia Pty Ltd"
<seabird@a...> wrote:
> I made a mast head anchor light using 6 LEDs mounted at 60 degreequadrants on a circular piece of circuit board. This assembly fits
into an off-the-shelf mast head light lens. The LEDs were about $3
each the lens $7 and a resister to lower the voltage to 3.6 volts was
$1.50. The light has been operating for a year, it has a light switch
which cost about $9 to turn itself on and off, but because the
current draw is negligible when compared to a normal filament bulb I
doubt if this is needed.
>
> Peter Adams
>
> PO BOX 618
> HERVEY BAY QUEENSLAND 4655
> AUSTRALIA
>
> TELEPHONE: 61 7 4125 3144
> FAX: 61 7 4125 3123
>
>
> [Non-text portions of this message have been removed]
I made a mast head anchor light using 6 LEDs mounted at 60 degree quadrants on a circular piece of circuit board. This assembly fits into an off-the-shelf mast head light lens. The LEDs were about $3 each the lens $7 and a resister to lower the voltage to 3.6 volts was $1.50. The light has been operating for a year, it has a light switch which cost about $9 to turn itself on and off, but because the current draw is negligible when compared to a normal filament bulb I doubt if this is needed.
Peter Adams
PO BOX 618
HERVEY BAY QUEENSLAND 4655
AUSTRALIA
TELEPHONE: 61 7 4125 3144
FAX: 61 7 4125 3123
[Non-text portions of this message have been removed]
Peter Adams
PO BOX 618
HERVEY BAY QUEENSLAND 4655
AUSTRALIA
TELEPHONE: 61 7 4125 3144
FAX: 61 7 4125 3123
[Non-text portions of this message have been removed]