After starting the machine, if user don't use the timing setting button, infrared sensor starts working when putting hand into the light, the default infrared sensor is 99s - when pressing 30/60/90s time buttons, the machine will work automatically - When timing is working, display will show the corresponding time, 30s/60s are count down, while 99s and infrared sensor are clockwise - Press 30s button for 5 seconds, when the number reach 25s, the display will be reversed - When the digital display flashes, it means that