| 摘要 |
PURPOSE:To display with a high accuracy an input AC signal level by a bar graph, by constituting a titled device so that an input AC signal is brought to a full-wave rectification, a level pulse corresponding to a peak level of a full-wave rectification output voltage is generated in a vertical scan period, also a display pulse of a prescribed pulse width is generated at every horizontal scan, and a CRT is driven. CONSTITUTION:Right and left audio signals are amplified 11, 31, respectively, brought to full-wave rectifications 12, 32, and a peak level of an output voltage is detected 16, 36, and supplied to comparators 17, 37. On the other hand, a vertical synchronizing pulse (e) is supplied to a transistor 55, a capacitor 18 is charged, and its accumulated voltage drops gradually and becomes a saw tooth voltage of a vertical scan period, compared 17, 37 with output voltages of the peak detecting circuits 16, 36, and supplied to AND circuits 21, 41. Subsequently, when a horizontal synchronizing pulse A is generated, a position pulse B, a display pulse C, a position pulse D and a display pulse E are generated in monostable multivibrators 23, 27 and 43, 47, respectively, and a pulse CE is supplied to a CRT driving circuit 51 through the circuits 21, 41, and displayed on a CRT20.
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