JPS5525873A - Recording-bias-current variable unit - Google Patents

Recording-bias-current variable unit

Info

Publication number
JPS5525873A
JPS5525873A JP9902178A JP9902178A JPS5525873A JP S5525873 A JPS5525873 A JP S5525873A JP 9902178 A JP9902178 A JP 9902178A JP 9902178 A JP9902178 A JP 9902178A JP S5525873 A JPS5525873 A JP S5525873A
Authority
JP
Japan
Prior art keywords
bias current
recording
recording bias
voltage
interval
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP9902178A
Other languages
Japanese (ja)
Inventor
Masamichi Yamada
Toru Sanbe
Naoya Fujita
Shigemitsu Higuchi
Koichi Tomatsuri
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP9902178A priority Critical patent/JPS5525873A/en
Publication of JPS5525873A publication Critical patent/JPS5525873A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: To obtain a broad-range and high-precision variable value of a recording bias current by using a unit with a variable range of a limited number of bits, by shifting the center value according to the variable value of the recording bias current.
CONSTITUTION: With switching element SW6 ON for a normal magnetic tape, voltage amplification determined by a ratio of resistance 14 to resistance 16 is performed by operational amplifier 23 at the next stage and the product of the amplified voltage and the voltage amplification degree of the initial stage is supplied to the input power supply of recording bias oscillation circuit 21, so that a recording bias current in proportion to the input power voltage will be outputted from circuit 21. At this time, turning ON and OFF switching elements SW1 to SW4 varies the center value of the bias current in sixteen steps and its interval can freely be fixed by adequately changing values of resistances 7 to 10, so that as the interval is shortened, higher precision can be obtained.
COPYRIGHT: (C)1980,JPO&Japio
JP9902178A 1978-08-16 1978-08-16 Recording-bias-current variable unit Pending JPS5525873A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9902178A JPS5525873A (en) 1978-08-16 1978-08-16 Recording-bias-current variable unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9902178A JPS5525873A (en) 1978-08-16 1978-08-16 Recording-bias-current variable unit

Publications (1)

Publication Number Publication Date
JPS5525873A true JPS5525873A (en) 1980-02-23

Family

ID=14235541

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9902178A Pending JPS5525873A (en) 1978-08-16 1978-08-16 Recording-bias-current variable unit

Country Status (1)

Country Link
JP (1) JPS5525873A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0388594U (en) * 1989-12-28 1991-09-10

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0388594U (en) * 1989-12-28 1991-09-10

Similar Documents

Publication Publication Date Title
JPS5672350A (en) Variable current source
JPS5514725A (en) Error amplifier circuit
JPS5634207A (en) Differential amplifier
JPS5591219A (en) Amplifier
JPS5296853A (en) Power amplifier
JPS5728410A (en) Voltage controlled type variable gain circuit
JPS5525873A (en) Recording-bias-current variable unit
JPS55108019A (en) Reference voltage generator
JPS5380944A (en) Semiconductor circuit
JPS5330852A (en) Differential amplifier circuit
JPS52112265A (en) Analog-digital conversion circuit
JPS5597619A (en) Reference signal generating circuit
JPS55117971A (en) Level indication circuit
JPS5374261A (en) Constant voltage equipment
JPS5776918A (en) A/d converter
JPS5467754A (en) Ad converter
JPS57193109A (en) Current amplifying circuit
JPS5651609A (en) Input circuit
JPS52119045A (en) Microwave semiconductor amplifier
JPS5362154A (en) Constant current bias circuit
JPS5331110A (en) Current value variable write circuit
JPS5668806A (en) Temperature control device
JPS5597099A (en) Bias voltage supply circuit
JPS5567660A (en) Power maker circuit
JPS53139957A (en) Gain control circuit