摘要 |
A voltage-converter and a signal processing circuit are disclosed. A voltmeter, a power meter and a three-phase meter each including the voltage-converter and the signal processing circuit are disclosed. Methods of making the voltage-converters, voltmeters, three phase meters and power meters, as well as operating and/or using these apparatus are disclosed. Apparatus including feedback paths with at least one voltage-converters, voltmeters, three-phase meters and/or power meters are disclosed. |