An X-ray apparatus comprises a general switch designed to eliminate the residual energy stored in capacitances of this X-ray apparatus. To this end, the general switch comprises several series-connected switch cells, each comprising a switch component constituted by a sidac parallel-connected with a thyristor. The number of cells is determined as a function of the voltage to be discharged. The apparatus has an external control circuit used to trigger the discharging of the first cell. Once the voltage in the first cell drops, the discharging of the second cell is triggered by an internal control circuit, and so on and so forth. The remaining cells are triggered at the same time, once they support a voltage greater than or equal to a predefined transition voltage. Thus, a chain reaction of the discharging of the stored energy is implemented.