Arrangement for the conversion of an electrical input quantity into a dc

Abstract

The arrangement for the conversion of an electrical input quantity into an electrical DC signal proportional thereto comprises two digital pulse duration modulators of limited resolution. The first digital pulse duration modulator supplies a first periodic pulse sequence which is pulse duration modulated with a quantization value, corresponding to the limited resolution, of the input quantity neglecting the quantization remainder. The second digital pulse duration modulator supplies a second periodic pulse sequence which is pulse duration modulated with the sum of the quantization value and of the quantization remainder multiplied by a predetermined factor. A system is provided for selectively transmitting pulses of the first and second pulse sequences to an averaging circuit in such a manner that the raito of the number of transmitted pulses of the second pulse sequence to the total number of transmitted pulses is equal to the reciprocal of the predetermined factor. The averaging circuit forms the DC signal means value of the combined sequence of transmitted pulses, whereby the resolution is enhanced with respect to the limited resolution of the digital pulse duration modulators.