Delta-modulation encoder

Abstract

In a delta-modulation encoding arrangement having step-size control drift voltages and miss-match between the charge and discharge pulses for the first integrating network in the feedback circuit produce an additional DC voltage on this integrating network. This additional DC voltage is compensated by an additional feedback circuit comprising a second integrating network. However, if the signal to be encoded rapidly decreases from a large to a small amplitude and when after this rapid decrease the information signal only has a small amplitude an additional distortion is introduced for these small signals. To obviate this a modulation arrangement is included in the extra feedback circuit, which modulation arrangement is controlled by a control signal which derives a control signal from the delta modulation output pulses. The energy contents of the delta modulation pulses which are applied through the modulation arrangement to the second integrating network is varied in such a way that this energy contents decreases when the step-size increases and vice versa.