| 摘要 |
PROBLEM TO BE SOLVED: To provide a head amplifier which does not often turn on/off a PAD even if a set level of a head amplifier gain fluctuates slightly in the vicinity of a switching point. SOLUTION: An amplification factor fixed amplifier 2 and an amplification factor variable amplifier 3 are successively connected to the output side of a PAD 1. A PAD control part 10 includes: a head amplifier gain set value obtaining part 20; an input signal obtaining part 11; a switching point setting part 12; and an on/off control part 13 for comparing the level of the head amplifier gain with a value of the switching point to turn on/off the PAD 1. Further, the PAD control part 10 includes: a hold range-setting part 14 for setting the range of a predetermined level from the switching point; and a PAD hold part 15 for comparing a set value of the hold range setting part 14 with the level of the input signal to maintain an on/off state of the PAD 1. The PAD control part 10 further includes a warning display part 16 for indicating that the PAD is in a hold state. COPYRIGHT: (C)2010,JPO&INPIT |
