APPARATUS FOR CONVERTING ANALOG-FORMAT SIGNALS TO PULSE-FORMAT SIGNALS

摘要

Apparatus for converting analog-format signals to pulse-format signals : Apparatus for converting an analog-format electrical signal or quantity (such as the magnitude of an electrical circuit element) into a corresponding pulseformat signal, preferably in the form of a train of periodic pulses the lengths of which are controllable as a percentage of the cyclic period. A pulsed duty cycle signal is developed in a negative feedback loop around an integrator having an analog-format input signal. The integrator output controls the d-c level of an up-and-down ramp signal which is fed to a comparator to produce pulses during the times the ramp voltage is above (or below) the firing threshold of the comparator. These pulses control a switch between the integrator input and a reference voltage so as to produce a negative feedback signal for the integrator. the negative feedback action controls the d-c level at the integrator output and thereby sets the pulse dutycycle to a value such that the average signal level through the pulsed switch to the integrator input relates in prescribed fashion to the applied input signal. The duty-cycle signal developed through such feedback action corresponds directly to the magnitude of the applied input signal.