Electricity: motive power systems – Positional servo systems – Pulse-width modulated power input to motor
Reexamination Certificate
2000-03-17
2001-12-04
Ip, Paul (Department: 2837)
Electricity: motive power systems
Positional servo systems
Pulse-width modulated power input to motor
C318S244000, C318S245000, C318S603000, C318S608000
Reexamination Certificate
active
06326757
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention is directed to a rotational pulse generating circuit for a brush-equipped or commutator DC motor which generates a pulse train signal in synchronization with motor rotation.
The co-pending U.S. Patent Application under the Ser. No. 09/429,922 discloses an electric circuit for detecting a rotational condition of a commutator or brush-equipped DC motor depending on a ripple pulse frequency which is indicative of a rotational number of the commutator DC motor. An output of such a circuit is in the form of a pulse train which is indicative of the rotational number of the commutator DC motor. This circuit is used to control a position of a vehicular movable member such as a seat or window pane which is driven by the commutator DC motor in such a manner that the output pulse train signal is fed to a micro-processor for positioning the vehicular movable member.
On the other hand, using the foregoing positioning device for a long time inevitably causes frictional wear inevitably between a brush and a commutator in the commutator DC motor, which causes the circuit to issue error pulses, thereby raising the question of how to cope with such an issuance of error pulses. The reason is that feeding the error pulses to the micro-processor makes the positioning of the vehicular movable member incorrect to a slight extent which cannot be neglected from the practical view point. Of course, such a problem can be eliminated by periodic inspections. However, doing periodic inspections are very cumbersome.
Thus, a need exits to make the foregoing electric circuit more reliable without periodic inspections.
SUMMARY OF THE INVENTION
It is, therefore, a principal object of the present invention to provide a rotational pulse signal generating circuit for a commutator DC motor which satisfy the need noted above.
In order to attain the foregoing object, the present invention provides a commutator DC motor which is made up of:
filter means for eliminating noise from the motor, the cutoff frequency of the filter means being variable depending on an external signal;
pulse shaping means for generating a ripple pulse indicative of a rotational number of the motor by wave-shaping an output of the filter means; and
clock generating means for generating a clock signal on the basis of the ripple pulse and a rotational condition signal of the motor, the clock signal being fed to the filter means for making the cutoff signal thereof variable.
REFERENCES:
patent: Re. 29431 (1977-10-01), Desai
patent: 3898690 (1975-08-01), Desai
patent: 4494509 (1985-01-01), Long
patent: 4924166 (1990-05-01), Roussel
patent: 5497326 (1996-03-01), Berland et al.
patent: 5550880 (1996-08-01), Abdel-Malek et al.
patent: 5710714 (1998-01-01), Mercadal et al.
patent: 5994932 (1999-11-01), Ando
patent: 6081490 (2000-06-01), Kuroda et al.
patent: 6111846 (2000-08-01), Hayashi
patent: 6157603 (2000-12-01), Okubo et al.
patent: 6172473 (2001-01-01), Oka et al.
patent: 6172952 (2001-01-01), Inokuchi et al.
patent: 6192018 (2001-02-01), Kobayashi et al.
patent: 6198085 (2001-03-01), Tateshi
patent: 6198354 (2001-03-01), Reinhardt et al.
patent: 6208216 (2001-03-01), Nasila
Birk, M.: “Unkonventionelle Drehzahlmessung Und -Regelung Bei Gleichstrommotoren Switched-Capacitor-Filter Bestimmt Drehzahl Ausder Welligkeit” Elekronik, DE, franzis Verlag GMBH. Munchen, vol. 33, NR. 25, pp. 71-72, XP002029304 ISSN: 0013-5658.
Aoki Kohji
Ishikawa Hitoshi
Kanie Hideyuki
Aisin Seiki Kabushiki Kaisha
Ip Paul
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
Rotational pulse generating circuit for commutator DC motors does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rotational pulse generating circuit for commutator DC motors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rotational pulse generating circuit for commutator DC motors will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2588497