I had an idea as far as how to interface a 12v led dimmer with an arduino's analog write input, while using a (relatively) high current source, such as a 12v w/w at 1.25a.
Could you wire up a mosfet that takes a 12v pwm signal at 1.25a (well decreasing as the load also connected to it for a 10w led turns on/off and more current flows into that circuit), and switches a low voltage current 5v 40ma signal on /off?
This could either be wired into an arduino, or directly to a buckpuck to dim led's, using those cheap 12v rf dimmers, which unfortunately don't dim @ 5v. I just feel like putting a voltage divider at the output of the pwm dimmer to trim it from 9-12v, down to 0-5v is going to put too much current into the driver, or arduino depending on how you have it wired up. I mean it only needs 40ma, and the pwm is pulsing 1a plus @ 5v.
Is this something i should worry about, or just use a voltage divider to get the 0-5v range i need from a 12v input to the dimmer which would put out 9-12v undivided voltage?
Something tells me putting that much amperage into an anduino or buckpuck's 0-5v control is just a bad idea. Thus the idea to use mosfets at the end of the pwm to switch the low current 5v voltage sources already provided by arduio's and buckpucks, the way it was meant to be done.