Christmas Wreath lighting controls PUBLIC

Not provided.

My father's favorite 'holiday season' was Christmas. As an electrician, he always loved the 'lighting part' for the tree & house. Since his death in 1997 I have placed a wreath on his headstone since then on behalf of my family. When battery operated incandescent mini-lights came available, I'd put a few sets in the wreath, however they wouldn't last more than a night. My daughter introduced me to newly available battery operated LED sets several years ago and overall they worked well lasting the 3 weeks needed. The only issue I've been having is when checking them often, I would find them off and need to reset them. This 2016 Christmas I added 2 10 LED lit ornamental sets to the 3 10 multi-colored LED set. As a tribute to my Dad, my plan here is to use all 5 of the LED sets together fed from one 4 'C' cell battery pack (instead of the existing 13 'AA's in use now) and have this ready for the 2017 Christmas season. I like to mix steady and flashing sets so there'll be a few independent flashers as well as a photo detector circuit that will turn the LEDS on at dusk and off in the morning to help save battery life. Using my DC power supply set at 6.0 volts the whole works only draws 60 ma max and I can turn down the supply to 4.5 volts and still works. At 4.4 volts the circuit shuts down. The electronics and battery pack are mounted on a custom etched double sided PCB with components suitable down to -20 deg C in an ABS weather-proof enclosure {MultiComp G346} as Christmas can be cold in Cape Breton. Completed in early March 2017, the wreath was placed outside for endurance testing. The first night I found the whole thing flashing on & off (not what I planned). What I found was that the clear, brighter LEDs lighting was being 'picked up' by the CdS sensor & turning it off. Then in the dark it would reset & turn back on only to be turned off again, repeating. I ended up painting a thin smear of liquid rubber on the lens to desensitize it & that worked. I plan to leave it out until the batteries die (out for a week now). If I can get 3 weeks, I'll be a happy guy. Running for 2 weeks now but I did have 1 problem. The whole thing shutdown with a temp ~-10C & would restart when it warmed up. I was using freeze spray on the components and when I got to the transistor everything shutdown. I replaced the plastic 2N3904 with a metal can 2N2222A and did the same test with no problem. However I was having some additional 'dropout' issues. The bi-polar transmitter was the issue as it was dropping 25 to 30% of the battery voltage across its collector (to emitter) leaving not enough to hold up the relay when it got real cold. I changed R7 from 10K to 100K & the 2N2222A got swapped for an IRF730PBF MOSFET. It works great & now Q1 only has <0.2Vdc across it leaving lots for the relay. The bonus is with more volts for the relay I can drop the power supply down to +3.4Vdc before a total dropout occurs. My bad with this: I probably would have saved a lot of grief if I had used a decent MOSFET if the first place! I'm ready for Christmas now!