Recording and decoding of time curves with recording devices - for pen recorders or magnetic tape recorders involves monitoring of trend of signal

摘要

A aperiodic signal receivable at all the recording points is delivered to the recording devices. The trend in respect of time of this signal is used to assign the individual recordings in time when they are decoded. The signal (111, 112) can be gained from low-frequency signal trains, especially from the low-frequency part of radio receivers tuned to a uniform program. There can be at least one stabilising circuit (S1, etc.) which emits a control voltage which is rapidly variable and one which is slowly variable. A trigger circuit (61) can be loaded by this control voltage.