Meter for accurately measuring integrated electric power

An electric power meter comprising:

• a first adder for producing a first sum signal representative of a first sum of a first additional analog signal and a first input signal representative of an analog electric current of an alternating current;
• a second adder for producing a second sum signal representative of a second sum of a second additional analog signal and a second input signal representative of an analog voltage of said alternating current;
• first sample-and-hold means connected to said first adder for sampling said first sum signal into a first sampled signal and for holding said first sampled signal as a first held signal;
• second sample-and-hold means connected to said second adder for sampling said second sum signal into a second sampled signal and for holding said second sampled signal as a second held signal;
• held signal selecting means connected to said first and said second sample-and-hold means for alternatingly selecting one of said first and said second held signals and the other of said first and said second held signals at a preselected period as a selected signal;
• converting means connected to said held signal selecting means for converting said selected signal into a digital signal;
• separating means connected to said converting means and ganged with said held signal selecting means for separating from said digital signal at said preselected period a first and a second separated signal so that said first separated signal is separated when said held signal selecting means selects said first held signal and that said second separated signal is separated when said held signal selecting means selects said second held signal;
• first memorizing means connected to said separating means for memorizing said first separated signal as a first memorized signal;
• second memorizing means connected to said separating means for memorizing said second separated signal as a second memorized signal;
• multiplying means connected to said first and said second memorizing means for calculating a product of said first and said second memorized signals to produce a product signal representative of said product;
• and
• integrating means connected to said multiplying means for integrating said product signal to produce a meter output signal representative of an integrated electric power of said alternating current.