I am going to switch a large ceiling mount led lamp on and off with an arduino. (it is similar but not exact to this... http://www.ebay.com/itm/Cool-White-12W-Panel-LED-Ceiling-Down-Cabinet-Kitchen-Bulb-Spot-Light-Lamp-/300891157305?pt=US_Chandeliers_and_Ceiling_Fixtures&hash=item460e82b339) The led power supply says input AC 85 to 365V 50/60hz and the output says DC 30-55V 300mA. It works great on 120VAC. This is for a traffic signal display. I'm going to switch them on/off around every 20 or 30 seconds. Should I switch the 120V input on/off with mosfets or should I switch the output with some bipolar transistors?
I suppose it would depend how often it will be switched on and off. Once every second or 2 you would prob want to switch the output so you don't damage the powersupply. Any slower and you should be good switching the 120vac input. Thats what i'm thinking anyway.