Patent ID: 11952997
Assignee: nan
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC F  H | IPC F

Claim 13:
14. The operating apparatus (104) according to claim 13, wherein said filtering unit (116) comprises three filtering stages, namely:
a first filtering stage (116a) comprising a simple resistive divider or a voltage sensor capable of measuring the direct, alternating and PWM voltage, so as to reduce the voltage value from high to low;
a second filtering stage (116b) comprising a filtering stage R, or first-order low-pass filter, for eliminating a high frequency PWM signal, leaving a DC signal unchanged and attenuating a residual AC signal of the frequency of the electric motor (102);
a third filtering stage (116c) suitable for isolating and amplifying the DC signal and further eliminating that residual AC signal by adding an offset so as to convert a measurement interval; said third stage being realized by means of a circuit with an operational amplifier.