DIGITAL COUNTING VOLTMETER FOR VARIABLE VOLTAGE AND EFECTIVE VALUE

The digital voltmeter of variable voltage root-mean-square assessment concerns the area of electricity-measuring technique and is determined for precisely measuring AC voltage within a wideband frequency. The purpose thereof is an increase in voltmeter accuracy. The designed voltmeter contains a block of automatics, measuring and testing channels consisting of a series-connected input changeover switch, amplifier and exchanger. The exchanger outputs are connected with a hybrid assessment equipment, while the output of the testing channel amplifier is connected with the input of the measuring channel converter through the first back converter. The back converter second input is connected to the testing channel converter input and voltmeter input, and the measuring channel exchanger output is connected to the second back converter. The novelty rests in the testing channel amplifier being controlled by a feedback of direct current over an additionally installed integrating amplifier the non-inverting input of which is connected with the second back converter through the switchover.