On line ripple determiner

The utility model discloses an on line ripple determiner, which is composed of a signal sampling conditioner, an A/D converter, a chip microprocessor, a liquid crystal display, a keyboard for the liquid crystal display, an alarm relay, a working power supply and a communication interface, wherein, the signal sampling conditioner takes out ripple voltage from control bus voltage; the ripple voltage is converted to digital signals through the A/D converter; the signals are calculated by the chip microprocessor, and a calculated result is displayed by the liquid crystal display. The utility model can carry out on-line ripple detection and can be used on an industrial site for a long time, and the utility model has low cost. The utility model can carry out the ripple measurement of a direct current power supply in an electric power department, a post telephone and telegraph department, etc.