it's better to use a timer like LM555 or just power on/off trough arduino code ?
To "drive" the led/led array, it's better to use a transistor, or not ?
I also need them to be switched on and off at relatively high frequency, and the should not burn after little use
? an array of 20-30 "super bright led" , or just some "high power" (1W/Led)