Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Uploaded on Mar 21, 2010
A total of six 3-Watt LED's (strange HHEC types), a few resistors, 2 BD675 NPN-darlington-transistors, and a 16F628 make up this high-power LED flash circuit.
I bought the blue LED's at a dump-store in IJmuiden. There is very little information about these things: only the white version of these round multi-die LED's has a datasheet somewhere on the internet. With a driving current of 600 mA for white, I decided to use the same current for the blue ones. With a resistor of 4,7 ohm in series with the 3 LED's, the current per group of LED's is about 650 mA (slightly overdriven... but probably harmless)
The flash-pattern is just a program of 4 different flash-patterns inside the uC.
The brightness is absurd, and one of the reasons why I don't like LED-lighting on emergency-vehicles.