Hi All,
I am currently doing a project to construct an underwater scuba dive flashlight.
The flash light will be using a 10W LED
(bought it from ebay http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290739819764 )
Power source is 18Volt PowerDrill rechargeable battery (19.5V measured)
( http://www.kmart.com/shc/s/p_10151_...c&srccode=cii_13736960&cpncode=32-173320936-2 )
my question is, whats the most efficient way to drive this LED.
basic rating for this LED:
forward voltage: 9-12V
Current: 1A
I dont need to dim the LED, i just need it to be on and off. so i am not planing to use PWM to drive it (I also don't think using a PWM will drive the LED more efficiently).
I have couple ideas in mind.
1) Simply drive it with a power resistor (I think it will be getting a big power dissipation from the resistor, because the voltage drop across it will be about 19.5V-12V= 5.5V)
2) use a DC to DC convertor converter to convert 19.5volt to 12volt and use a smaller value power resistor to drive the LED. However, I am not sure what is the typical power dissipation of a DC to DC convertor.
Any other suggestion would be greatly appreciated!
Thanks in advance!!
I am currently doing a project to construct an underwater scuba dive flashlight.
The flash light will be using a 10W LED
(bought it from ebay http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290739819764 )
Power source is 18Volt PowerDrill rechargeable battery (19.5V measured)
( http://www.kmart.com/shc/s/p_10151_...c&srccode=cii_13736960&cpncode=32-173320936-2 )
my question is, whats the most efficient way to drive this LED.
basic rating for this LED:
forward voltage: 9-12V
Current: 1A
I dont need to dim the LED, i just need it to be on and off. so i am not planing to use PWM to drive it (I also don't think using a PWM will drive the LED more efficiently).
I have couple ideas in mind.
1) Simply drive it with a power resistor (I think it will be getting a big power dissipation from the resistor, because the voltage drop across it will be about 19.5V-12V= 5.5V)
2) use a DC to DC convertor converter to convert 19.5volt to 12volt and use a smaller value power resistor to drive the LED. However, I am not sure what is the typical power dissipation of a DC to DC convertor.
Any other suggestion would be greatly appreciated!
Thanks in advance!!