I have a broken Dremel 398 (with a small digital display that is always ON) and I am quite puzzled about 3 things (I am thinking maybe I could recreate the PCB with an Attiny, if I could understand about AC magic).
1) How they convert 230V AC to 5VCC for the PIC with so little components?

2) How do they detect the RPMs in the microcontroller only with 1 wire around the stator?

3) The microcontroller and LCD are always powered on, but there is a switch that turn the Dremel ON and OFF (with a soft start), how does the uC knows WHEN to do the soft start/stop?

PCB:


Thanks a lot for your time
