Im looking to make a light array with 1w chips but i need to be able to pulse the light on and off rapidly. I want to flash the leds from 1hz to 60hz while being able the PWM dim them. I achieved this with 5mm leds but now want to use 1w chips.
I'm trying to figure out if the best way to do this is to use transistors or mofsets to do this
If anyone was as any input or parts in mind it would be appreciated.
You can use simple transistors or MOSFETs. But, make sure to calculate the power dissipation in the current limiting resistors and use large-enough resistors to handle the power (and heat).
How big is the array going to be?
When you get to around 1W (or more), the standard approach is to use a special controlled-current switching supply instead of a current limiting resistor ([u]examples[/u]). You can build one, but it's not the easiest thing to build. You would need one supply for each LED, or at least for each row & column in your array, but doubt the standard supplies can be used to control rows/columns. You'd need to get a dimmable supply, and you'd still need a small transistor because these things usually need a 10V control signal.
So the driver remain on I'm just going to control the blink frequency with the dim input ie if I want the LED at 100% brightness for 1hz set the dim input at 100% for .5 sec then .5 sec at 0% Or if i want it at 50% brightness set it at 50% for .5sec then 0% for .5sec, ect.