I have just completed a 12V DC based LED light which uses 18 Superflux (four legged/ Piranha) LEDs. These LEDs have capabilty of taking currents upto 70mA. I have divided them into 6 strings of 3 LEDs each.
Each string is driven by a constant current source. This was the reliability is improved and we can use simple transistors to create the constant current source.
By default I drive the LEDs at around 34mA.
There are 4 Amber/Yellow LEDs which I use and these are put in place so that the light will work even if the battery voltage drops to below 10.5 Volts (albeit with reduced brightness).
I have just put up these on ebay for sale. And some have asked me to supply these with all white LEDs. I have obliged but would prefer to sell them with the 4 Amber/yellow LEDs.
Here are the pictures
Each string is driven by a constant current source. This was the reliability is improved and we can use simple transistors to create the constant current source.
By default I drive the LEDs at around 34mA.
There are 4 Amber/Yellow LEDs which I use and these are put in place so that the light will work even if the battery voltage drops to below 10.5 Volts (albeit with reduced brightness).
I have just put up these on ebay for sale. And some have asked me to supply these with all white LEDs. I have obliged but would prefer to sell them with the 4 Amber/yellow LEDs.
Here are the pictures
