A cable TV amplifier system, including: an amplifier module, including a body, a power connecting port, a signal input port, and a plurality of signal output ports; and a power converter, including an AC power input terminal, at least one DC power output terminal, and a switching power converting circuit for converting an AC voltage to a DC voltage to power the amplifier module; wherein, the switching power converting circuit includes a surge protection circuit, a bridge rectifying circuit, an energy transmission unit, a feedback unit, and a control unit, and the control unit will stop outputting a pulse width modulation signal when the AC voltage has an amplitude larger than a first level or smaller than a second level, the first level being higher than the second level.

A non-contacting system for visualizing and analyzing periodic movements in machinery includes at least one video acquisition device that acquires sampling data as a video comprising a plurality of video image frames and a data analysis system including processor and memory, and a computer program operating in the processor to filter movements depicted in the video to a specific frequency to normalize the phase in a plurality of objects in the video representing parts or components of the machinery, to compare the movements of such objects which in some embodiments provides for construction of a modified video to visually exaggerate the apparent movement of the at least one of the plurality of objects.