SPEED CONTROLLER OF PCM RECORDER

摘要

PURPOSE:To prevent a wow and a flutter during a tape run by detecting the frequency variation of a write clock signal from variation in difference between the address counter output and read address counter output of a buffer memory. CONSTITUTION:The time-axis correction of a reproduced digital signal is carried out by a buffer memory 1; and a write address counter 2 performs counting by a write clock signal synchronized with a signal from a tape to specify a write address signal to the memory 1, and a read address counter 4 performs counting by a read clock signal 5 from a quartz oscillator, etc., to specify the read address of the memory 1. A difference between both the address is calculated by a subtracting circuit 6 and fed back to a capstan motor through a D/A converting circuit 7 to control a tape speed. Consequently, the evil influence of a wow and a flutter upon signal processing is removed by the simple constitution.