Patent ID: 8433743

Claim:
A Root Mean Square (“RMS”) meter comprising: a current interface on which a current signal is received; at least one analog-to-digital converter that outputs a digitized low frequency current signal corresponding to a low frequency component of the current signal and a digitized averaged absolute value wave form corresponding to a high frequency component of the current signal; a first current squarer, coupled to receive the digitized low frequency current signal, the first current squarer generating a digitized low frequency squared current signal; a first multiplier, coupled to receive the digitized averaged absolute value waveform and a waveform factor, the first multiplier generating an approximated RMS value corresponding to an RMS value of the high frequency component of the current signal; a second current squarer, coupled to receive the approximated RMS value, the second current squarer generating a squared RMS value; a summer, coupled to receive the digitized low frequency signal and the squared RMS value, the summer generating a summed squared current output corresponding to both high and low frequency components of the current signal; a first low pass filter, coupled to receive the summed squared current output, the low pass filter generating an averaged summed squared current output; and a square-root module, coupled to receive the averaged summed squared current output, the square-root module generating an RMS current level corresponding to both the high frequency and low frequency components within the current signal.