Several years ago, I got tired of frequently replacing the halogen incandescent bulbs in our landscaping lights. The incandescent bulbs were replaced with LED arrays that were to be used to replace the dome light blubs in cars. Even if you never buy from Amazon it is a good reference to see what is available in the way of LED dome lights. Many colors including white are available. Figure 1 shows what is in the garage, a bridge rectifier and toggle switch were added to the original transformer/timer. This arrangement powers the out door lights with unfiltered DC and the ability to reverse the polarity of the DC going to the lights. By changing polarity, different color lights are activated in the outdoor lights. We display white lights most of the year and red and green during the holidays. Figure 2 shows what has replaced the incandescent bulbs. The usual way to indicate polarity using two LEDS is to wire them anti-parallel so that one lights for a certain polarity and the other lights when the polarity is reveresed. This would probably work with these LED arrays but this would reverse bias the off array by over 12 volts. There are no specifications available on what the max inverse voltage these LED arrays will tolerate so they were wired as shown in Figure 2. This arrangement limits the inverse voltage across the off array to less than one volt. Extra “goodies” have been added to these LED arrays over the years, some have a built in bridge so they are not polarity sensitive, some have a built in resistor so they look like an incandescent bulb to the car canbus error detect system. These will work just fine as landscape lights. Some newer ones have a built in IC that provides a constant current to the array I have never tried these and I don’t know how they would react to the unfiltered DC. Use the simplest array available, they cost less and work just fine.
Long Rope Ranch 