| 摘要 |
<p>The invention relates to a system for measuring the electrical energy consumed by a load. The system can be used in an energy meter or a wattmeter. The system employs a Hall effect element (23) with supply circuits (5, 18, 25), and switching means (9, 11) to control a relative phase change between the bias current and the magnetic field associated with the Hall effect element to cause thereby a change in the Hall output voltage which is fed to signal processing circuits (26, 27, 38, 47) and measuring circuits (48 to 51, 72, 85) to give a measure of the electrical energy consumed, which is independent of errors arising from the self-field effect of the bias current in the Hall effect element (23).</p> |
