JPS64805U

JPS64805U -

Info

Publication number: JPS64805U
Application number: JP9611687U
Authority: JP
Priority date: 1987-06-23
Filing date: 1987-06-23
Publication date: 1989-01-05

Description

[Brief explanation of the drawing]

第１図はこの考案の一実施例であるフレキシブ
ルデイスクドライブ装置におけるイレーズ電流の
制御回路を示す回路構成図、第２図ａ及びｂは第
１図のイレーズ電流の制御回路における各部の電
流を示すタイミングチヤート、第３図は従来のフ
レキシブルデイスクドライブ装置におけるイレー
ズ電流の制御回路を示す回路構成図である。図において、１……書込みゲート（ＷＲＩＴＥ
ＧＡＴＥ）信号、２ａ……オンデイレー／オフ
デイレータイマ（ＯＮＤＥＬＡＹ／ＯＦＦＤ
ＥＬＡＹＴＩＭＥＲ）回路、２ｂ……第１の時
定数回路、２ｃ……第２の時定数回路、２ｄ……
第３の時定数回路、３……イレーズ電流ドライブ
（ＥＲＡＳＥＤＲＩＶＥ）回路、４……イレー
ズヘツド（ＥＲＡＳＥＨＥＡＤ）、４ａ……第
１のイレーズヘツド（Ｓ０）、４ｂ……第２のイ
レーズヘツド（Ｓ１）、５……選択（ＳＥＬＥＣ
Ｔ）信号、６……選択（ＳＥＬＥＣＴ）回路、７
……正規（ＮＯＲＭＡＬＤＥＮＳＩＴＹ）信号
、８……スイツチ回路である。なお、図中、同一
符号は同一、又は相当部分を示す。 FIG. 1 is a circuit configuration diagram showing an erase current control circuit in a flexible disk drive device that is an embodiment of this invention, and FIGS. 2 a and b show currents at various parts in the erase current control circuit of FIG. 1. Timing chart FIG. 3 is a circuit configuration diagram showing an erase current control circuit in a conventional flexible disk drive device. In the figure, 1...Write gate (WRITE
GATE) signal, 2a...On delay/off delay timer (ON DELAY/OFF D
ELAY TIMER) circuit, 2b...first time constant circuit, 2c...second time constant circuit, 2d...
3rd time constant circuit, 3... erase current drive (ERASE DRIVE) circuit, 4... erase head (ERASE HEAD), 4a... first erase head (S0), 4b... second erase head (S1), 5...Selection (SELEC)
T) Signal, 6...SELECT circuit, 7
. . . NORMAL DENSITY signal, 8 . . . Switch circuit. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims

[Scope of utility model registration request]

an on-delay timer circuit operated by the write gate signal and controlled by the first time constant circuit; and a second on-delay timer circuit operated by the write gate signal and controlled by the first time constant circuit.
The on-delay time and off-delay time of the erase current are controlled by the off-delay timer circuit, which is controlled by a time constant circuit, and a switch circuit that turns on and off according to a regular signal, and the timing created by the on-delay/off-delay timer circuit. A flexible disk drive device characterized by comprising an erase current drive circuit for controlling.