Back in this post I vented of the frustration that many common varieties of 2-wire LED Christmas light default to an annoying blinky sequence, rather than just turning “on” as you’d like them to. Sadly there are no easy solutions to this problem.
Instead I threw together my own controller. A 12V power supply is plugged in one end, lights are connected to the other. They turn “on”. No pressing buttons. Simple.
The controller is designed for a few different control and power supply arrangements.
Input voltage is typically 12V. The board will step up the drive voltage to between 24-36V which is adequate for most 2-Wire LED Christmas light strings. The “DC OUT” Header can also be used as an input, for example if you have a DC supply available which already outputs the appropriate voltage for your lights.
A heatsink is required for driving larger light sets.
By default a 555 timer is used to generate a clock signal which drives a latch which in-turn drives an L298N full bridge generating the output required for “on” output.
Optional MCU Control
This year (2022) my lights feature custom microcontroller driven sequences using this setup:
An optional control header is provided to connect the board (for example) to an Arduino for more complex sequences. In this case U1 must not be fitted. I would recommend socketing U1 to allow for this option. The Arduino can be powered from this header.
Personally I don’t use Arduinos. The source code for the above setup is here. I’ll probably document it and design a proper PCB for next Christmas (2023).