| 摘要 |
1. Device for measuring and visualizing the amplitude of a low frequency signal (S), said device comprising video visualizing means (4) defining a field period (T) and a line period (TI ), and means (22) for deriving a periodic saw-tooth signal (SR ), characterized in that the saw-tooth signal (SR ) has its period equal to the field period (T) and is synchronous with the field synchronizing signal (J), and in that the device comprises first voltage comparing means (20) receiving said low frequency signal (S) or a signal (S6 ) having an amplitude depending on the low frequency signal according to a predetermined variation law and said saw-tooth signal (SR ) for deriving first pulses at times corresponding to the equality of the amplitudes of the two received signals (S or S6 , SR ), means (33) for producing second pulses recurrent with the line period (TI ), and first switching means (30, 31) controlled by the first pulses (I) for transmitting one of said second pulses (I2 ) to input video means (40, 41) of the video visualizing means (4) in response to the detection of each first pulse (I), the width of the first pulses (I) being greater than the difference between the line period (TI ) and the width of the second pulses (I2 ). |
