Device for displaying a measuring voltage, for example an ekg signal, on

Abstract

In an illustrated embodiment an analog signal is sampled by means of a bucket brigade store. The stored samples are then repeatedly cycled through the store during refreshment of a visual display via a controlled amplifier. The storer also receives a reference voltage sample which is also circulated and which is periodically sampled at the storer output and compared with the input reference voltage, any deviation being utilized to control the amplification of the amplifier to maintain the reference voltage sample at substantially a constant level, and thus to maintain essentially unity amplification during the cyclical operation of the storer. The reference voltage sample can be selectively obtained from the measured signal or by means of a separate reference voltage generator. In the latter instance, the reference voltage sample is to be blocked so as to avoid display thereof, a previous sample of the measuring signal, for example, being displayed instead. For example, a scanner switch at the output of the bucket brigade storer may alternativey supply successive signal samples to the display and the reference voltage sample to a voltage comparator controlling amplification, a storage capacitor in the display circuit retaining the previous signal sample value during each amplifier calibration cycle.