Reply to "Flickering LED's"

The suggestions for a full-wave rectifier and filter cap are the hot ticket, that will eliminate the flicker.  I'd recommend at least a 1,000uf 35V capacitor for your application.  With DC from a bridge, you'll also get more voltage, so the resistor will have to be sized appropriately.  Compute the values as if you're getting around 20 VDC from the supply.  I'd probably start with a 33 ohm 2W resistor if both strings of those LED's will be in parallel, that will be totaling 240ma.