... used for limiting the Inrush Current in the power supply loop of every kinds of power supply, ballast / CFL etc. and the heating ... , which is mainly used in Switching Power Supply, UPS Power Supply, CFL, Ballast, Circuitry of Power Supply, etc.WMF21 series NTC thermistors ... used for limiting the Inrush Current in the power supply loop of every kinds of power supply, ballast / CFL etc. and the heating ...