True on-line double conversion design. Sine wave pulse width modulation. IGBT inverter design. Advanced Battery Managemen. Model No.LS-1KVALS-2KVALS-3KVALS ... LCD Indicator StatusInput/Output Voltage,Frequency,Output Power,Battery,Utility,Inverter,Overload,Fault,BypassCommunication PortRs232/USBInterfaceMonitor of Utility Fault,Power ... 13.50 14.00 35.00 38.00 Double Conversion Sine Wave Online UPS