| 摘要 |
<p>Apparatus for measuring the mean instantaneous power supplied to an electrical device computes the product of two voltage signals each proportional to the instantaneous voltage and current respectively. A self-biasing current source generates a DC signal current proportional to the magnitude of one voltage signal and a log-antilog multiplier circuit (50) computes the product of the DC current signal and the other input voltage signal. A current mirror (60) connected to the multiplier cancels DC offset currents to improve accuracy of the apparatus.</p> |
