公开(公告)号：JPH06209576A

公开(公告)日：1994-07-26

申请号：JP29557193

申请日：1993-11-25

Applicant: SGS THOMSON MICROELECTRONICS

Inventor： PAORO MENEGORI ,  MAAKU II ROOBAA

IPC: G05F3/26 ,  G01R19/22 ,  H02M7/21 ,  H02M7/217

Abstract: PURPOSE: To obtain a highly accurate high speed full-wave rectifier by providing a first current mirror circuit connected with the input terminal of an amplifier, and a second current mirror circuit connected with the output terminal of the amplifier. CONSTITUTION: A current bridge circuit 30 comprises first and second current mirror circuits 40, 50. An amplifier 20 has a negative input end 22 to be connected with the first terminal 34 of the current bridge circuit 30, a positive input end 24 to be connected with a reference voltage VREF, and an amplifier output end 26 to be connected with the second terminal 36 of the current bridge circuit 30. The full-wave rectifier 10 has a circuit input end 12 connected with the negative input end 22 through an input resistor RIN, and a circuit output end connected with the output end 32 of the current bridge circuit 30. Since two current mirror circuits are included, a highly accurate high speed full-wave rectifier can be realized.

公开(公告)号：JPH0686585A

公开(公告)日：1994-03-25

申请号：JP3891593

申请日：1993-02-26

Applicant: SGS THOMSON MICROELECTRONICS

Inventor： MAAKU II ROOBAA ,  FURANSESUKO KAROBORANTE

IPC: H02P6/16 ,  H02P6/18 ,  H02P6/02

Abstract: PURPOSE: To provide a method capable of detecting the back electromotive force of a floating coil for a polyphase DC motor and capable of being used even at a low speed of the motor. CONSTITUTION: A circuit and a method, which detect the time when a back electromotive force of a motor coil 11, passes through at a specified level have a circuit, supplying a voltage which is proportional to the back electromotive force of the motor coil 11 and a circuit supplying voltage proportional to a reference voltage. A first bias voltage is added to a voltage proportional to back electromotive force for generating a first added voltage, and a second bias voltage is added to the reference voltage, when a change in the fixed direction of the back electromotive force of the motor coil is scheduled to generate the second added voltage. When the first added voltage is made larger than the second added voltage at a specified level, a comparator generates an output change.