Hardware, the timer consists of the one described at:
https://github.com/StoicaT/Timer-with-Arduino-and-rotary-encoder-1
to which is added the power supply and instead of the classic relay a power actuating element. Everything is encased in a metal box.
Software can be the one from the previous address, or from the address:
https://github.com/StoicaT/Timer-with-Arduino-and-rotary-encoder-2
or the one in this repository.
In the first two cases, we have a countdown counter.Its programming is described at the appropriate addresses.
In the last case we have a timer whose duration and ON / OFF cycles are preset. There are 3 predefined programs that operate an electric motor that can operate a mixer (for dough for example). Its programming is simple:
-Choose one of the 3 programs by rotating the Encoder.
-Start the program by pressing the Rotary Encoder button.
The program given in this repository can be easily modified for other applications, because the number of ON / OFF cycles can be easily modified, as well as their duration. More to https://www.instructables.com/id/Power-Timer-With-Arduino-and-Rotary-Encoder/