/diy/ - Do It Yourself

I built this LED Christmas tree from a Velleman kit when I was little. I found the kit's manual from their web site and it claims 8 mA current consumption from a 9 V battery.

How much would it improve the battery life of the tree if this simple circuit was re-implemented with a low-current CMOS logic IC? I guess CD4000 series IC would be optimal in this regard: very low (<10 µA) supply current and operating voltage from 3 V up to 15 V.

Another way to save a lot of battery power would be to add an LDR light sensor and a low-power comparator IC such as MAX921. It would automatically shut down the blinking light show during the day.