Title:
RECORDING LEVEL CONTROLLER FOR DIGITAL RECORDER
Document Type and Number:
Japanese Patent JP3084547
Kind Code:
B2
Abstract:
PURPOSE: To reduce the mounting area of a board by eliminating analog AGC circuit thereby simplifying the circuitry.
CONSTITUTION: A high speed switching element 34 in a record volume circuit 32 is subjected to ON/OFF control depending on the duty of a PWM signal delivered from a PWM controller 44. Consequently, the analog output signal from an operational amplifier 35 is subjected to level control before being subjected to A/D conversion through an A/D converter 38. A microcomputer 42 detects the level over of a digital signal subjected to A/D conversion and processed through a digital signal processing circuit 39. The volume value is then decreased step by step until the level over is eliminated and the duty of PWM signal from the PWM controller 44 is decreased step by step thus preventing the level over.
Inventors:
Kenji Uemoto
Application Number:
JP27754694A
Publication Date:
September 04, 2000
Filing Date:
November 11, 1994
Export Citation:
Assignee:
Sharp Corporation
International Classes:
G11B20/10; G11B19/02; G11B20/04; (IPC1-7): G11B20/10; G11B20/04
Domestic Patent References:
| JP6139978A | ||||
| JP2218062A | ||||
| JP3113764A |
Attorney, Agent or Firm:
Kazuhide Okada