With its low part count this easy build timer project makes a good introduction to electronics. The timer uses a resistor capacitor network to provide a time delay of between 1 second and 4 minutes, which is set by the PCB mount variable resistor. When the button is pressed the LED changes from red to green, then at the end of the time interval it turns red. This kit contains: 1 x 2AA battery https://elecena.pl/product/16395861/easy-build-timer-project-kit 2020-04-06 https://elecena.pl/product/16395861/easy-build-timer-project-kit 2020-09-01 https://elecena.pl/product/16395861/easy-build-timer-project-kit 2021-03-02 https://elecena.pl/product/16395861/easy-build-timer-project-kit 2025-07-09