TRUE RMS TO DC CONVERTERS

摘要

An apparatus for converting a complex AC voltage wave to an equivalent DC value which is a measure of its true RMS value and which may then be read on an accurate indicating device such as a digital voltmeter, incorporating thermal converters and operational amplifiers in a temperature-compensated configuration. The apparatus maintains a portion of an unknown AC voltage wave, which is thermally converted into a DC voltage, substantially equal to a DC reference voltage. A portion of a DC output voltage is also maintained substantially equal to the DC reference voltage. Since the proportioning means for the complex AC voltage wave and the DC output voltage is the same, the true R.M.S. value of the complex AC voltage wave is equal to the DC output voltage.