Power transformer is suitable for 800 w, the largest output power 500 w. Small transformer can't be output power, such as 50 w transformer cannot output power 80 w. Voltage stabilizing function: when the transformer is close to 12 v, no voltage stabilizing function, the output pulse, voltage stabilizing function for 8 v to 10 v transformer is, there are fine for the customer to adjust the voltage, voltage stabilizing function to meet the 220 v to 220 v voltage sampling board Have input reverse connect protection function, With 10 v low voltage under-voltage protection function. Output frequency: 50 hz, could be 'tuned' (before shipment has been adjusted to 50 hz), Output voltage, adjusted to about the 220 v before shipment, this kind of ac side voltage regulator has fluctuated. With a small fan when can in transformer output capacitance with fixed waveform, can output approximately sine wave, but a capacitive consume a certain amount of power, reduce the conversion efficiency, do not bring the perceptual load, plus a capacitor is not recommended. The input voltage: 10 v to 15 v Output waveform: square wave, sine wave (according to the use of transformer and 220 v voltage feedback decision, no feedback square wave) Quasi sine wave inverter driven plate Need external 50 hz, 220 v transformer 8-12 v transformer, even 10 v above the feedback voltage 220 v, also may not be to voltage stability, low pressure side of a winding can (standard transformer silicon steel sheet) size:88 x 72 x 46mm Material:ABS colour:Green+white Package Contents: 2 x inverter drive board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.