DIGITAL DATA SLICER CIRCUIT FOR DIGITAL TELETEXT SIGNALS

A digital data slicer circuit causes the slicing level to track a teletext signal in optimum fashion even if the teletext signal has many successive zero crossings. The digital data slicer circuit substantially prevents any lock-in in either of two other, stable states. This is achieved essentially by applying a zero signal via two changeover switches to an accumulator and a sign inverter when many successive zero crossings are detected by a logic circuit that controls the changeover switches.