Claims
- 1. A magnetic head drive circuit comprising:
- a magnetic recording/playback head including a recording/playback coil divided by a center tap into a first coil and a second coil
- a drive voltage source having one electrode thereof connected with said center tap;
- a first means for supplying a write current to either one of an end of said first coil opposite to said center tap and an end of said second coil opposite to said center tap depending on a logic level of a control signal supplied to the magnetic head drive circuit;
- a second means for supplying an additional current exclusively to said end of said first coil in response to said control signal so that said supplying of the additional current is carried out in synchronization with supplying of said write current to said end of said first coil; and
- control means for generating an additional control signal for prohibiting the supply of said additional current to said end of said first coil regardless of said logic level of said control signal, when said additional control signal is active.
- 2. The magnetic head drive circuit as claimed in claim 1, wherein the intensity of said additional current supplied from said second means to said first coil is established so as to compensate for leaking of erase flux.
- 3. The magnetic head drive circuit as claimed in claim 1, wherein said first means comprises:
- a first current source for supplying said write current to said recording/playback coil;
- first switching means for connecting a current output terminal of said first current source to said end of said first coil in response to said control signal; and
- second switching means for connecting said current output terminal of said first current source to said end of said second coil in response to an inverted signal of said control signal.
- 4. The magnetic head drive circuit as claimed in claim 3, wherein said second means comprises:
- a second current source for supplying an additional current to said first coil;
- third switching means for connecting said end of said first coil to a current output terminal of said second current source in response to said control signal; and
- fourth switching means for connecting said one electrode of said drive voltage source to said current output terminal of said second current source in response to said inverted control signal.
- 5. The magnetic head drive circuit according to claim 4, wherein said control means comprises:
- fifth switching means for connecting between said one electrode of said drive voltage source and said current output terminal of said second current source in response to said further control signal, wherein, when said additional control signal is made a first logic level to control the fifth switching means to turn off, said third and fourth switching means are placed in an operable state, and when said additional control signal is made an active second logic level to control the fifth switching means to turn on, said third and fourth switching means are placed in an off state regardless of said logic level of said control signal.
- 6. The magnetic head drive circuit as claimed in claim 5, wherein said first to fifth switching means are all provided with semiconductor elements, and said first and second current sources are provided with first and second current mirror circuits, respectively, which share same current input circuit.
- 7. The magnetic head drive circuit as claimed in claim 5, wherein said first through fifth switching means are all provided with NPN bipolar transistors, and a high level of said additional control signal is set at a higher value than the high level of said control signal.
- 8. The magnetic head drive circuit as claimed in claim 5, wherein said first through fifth switching means are all provided with N-channel MOS transistors, and a high level of said additional control signal is set at a higher value than the high level of said control signal.
Priority Claims (1)
Number |
Date |
Country |
Kind |
5-254104 |
Oct 1993 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 08/317,771, filed Oct. 4, 1994.
US Referenced Citations (5)
Foreign Referenced Citations (3)
Number |
Date |
Country |
52-46807 |
Apr 1977 |
JPX |
63-44308 |
Feb 1988 |
JPX |
1-263904 |
Oct 1989 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
317771 |
Oct 1994 |
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