Abstract: A phase sampling protection device substantially includes a phase sampling circuit coupled between a tube circuit and a protection circuit. The phase sampling circuit captures a voltage signal and a current phase signal of the tube circuit for comparison, using phase comparing technique to detect an anomaly of the tube, if the tube doesn't function normally, then the phase sampling circuit driving the protection circuit to shut down the power supply of the tube to keep a transformer from burning down and other safety issues from happening.

Abstract: A tap-off transformer includes a coil base, a core and wires. The coil base has isolating walls placed outside and using isolating walls to form a first winding slot on a primary side area and a plurality of second winding slots on a secondary side area. Different kinds of wires could be winded inside the first and second winding slots. A wiring start point inside the plurality of second winding slots on the secondary side area is placed on one of the isolating walls, with coils starting from the start point to extend outwards to either sides of the secondary side area and ending at either sides. The coil base has a hollow structure for placing the core to form a transformer structure. The present invention provides isolating walls and a winding design to increase a rated voltage of the transformer and to improve the stability of the transformer.

Abstract: A double frequency signal generator to which a synchronization signal having a duty cycle of 1% to 999% is inputted. The synchronization signal is used for triggering of a switching component at positive and negative edges to generate a triangular-wave signal. An average of voltages of the triangular-wave signal is acquired and compared with the triangular-wave signal at a comparator to generate a square-wave having a duty cycle of 50%. Then, the square-wave signal is used for triggering at positive and negative edges to generate a double frequency signal. As such, the high cost issue and the limitation of a square-wave input signal occurred in the prior art may be efficiently overcome.