In the "220V AC Cooling Fan" system SPCE061A the need to use 3.3V power supply, AMS1117 chip production. AMS1117 is a positive LDO, AMS1117, there are two: one for fixed output voltage, 220V AC Cooling Fan" output voltage values are: 1.5V, 1.8V, 2.5V, 2.85V, 3.0V, 3.3V; another is to regulate the output voltage. AMS1117 internal integrated thermal protection circuit and over current protection circuit. In order to protect the "220V AC Cooling Fan" of stability at the output to be connected to at least 22UF a tantalum capacitor voltage generated by the AMS1117 3.3V constituted