Why not use a mosfet with low side switching
You're on the right path with a mosfet switch- since you're switching DC at 30 something volts. The parts you mentioned are fine for the application, logic rated and 35 milliohms on resistance. That's about 0.3w dissipation at 3 amps so a small heat sink should be fine as well. You should have a fuse (poly or thermal) inline with the LED since 100W is enough to heat things to dangerous levels, given the right circumstances.Your original post prompts me to say that you can kill yourself or burn the house down just as easily with a UL listed relay as a $1 bargain relay. When it comes to load switching, it's more about specifying the most appropriate device, with the required ratings, proper protective devices and installed in a proper enclosure with the correct wire size and insulation. Easy, right?The power switch tail meets a market demand for makers that want to build and sell things that control AC mains without having to go through the incredibly costly product testing required to market a consumer product. That's how it survives at what seems to be rather high prices for what it does. One competitor and *poof* their margins would disappear.
A 100watt 34VDC~3A ~34volt 3Amp COB LED needs a constant current driver/supply.Not a relay or mosfet or constant voltage supply.Google something like "Meanwell dimable 100watt LED driver".Leo..
and using the TimerOne library to generate a 10KHz PWM means you get smooth, efficient dimming functionality if you require it.
That does not make sense. 10kHz is way to high to be able to dim low enough, even for 8-bit PWM.LDHxxxx dimmers work on about 500kHz, and you need at least one ot two periods of that to make the dimmer work.Do the maths.Leo..