(19)
(11) EP 1 441 372 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
24.10.2007 Bulletin 2007/43

(43) Date of publication A2:
28.07.2004 Bulletin 2004/31

(21) Application number: 03029925.9

(22) Date of filing: 29.12.2003
(51) International Patent Classification (IPC): 
H01F 7/18(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR
Designated Extension States:
AL LT LV MK

(30) Priority: 27.01.2003 JP 2003017913

(71) Applicants:
  • Kyowa Denki Kogyo Kabushiki Kaisha
    Kanazawa-shi, Ishikawa-ken (JP)
  • TSUDAKOMA KOGYO KABUSHIKI KAISHA
    Kanazawa-shi Ishikawa-Ken (JP)

(72) Inventors:
  • Miyashita, Tatsuo
    Kanazawa-shi Ishikawa-ken (JP)
  • Madokoro, Akio
    Takefu-shi Fukui-ken (JP)
  • Yamada, Shigeo
    Komatsu-shi Ishikawa-ken (JP)

(74) Representative: Turi, Michael et al
Samson & Partner Widenmayerstrasse 5
80538 München
80538 München (DE)

   


(54) Actuator driving apparatus and method


(57) An actuator driving apparatus (10) comprising at least one processing circuit (12) including: a first switching device (32) placed between an exciting coil (14) of an actuator and a dc power source (16,18) and operated by a pulse-width modulated signal (S4) generated so as to correspond to an overexciting period (T2) and a holding period (T3) subsequent to the overexciting period (T2) in a drive period (T1); a reflux circuit (36) connected in parallel to the exciting coil (14) and including a fly-wheel diode (44) and a second switching device (42) connected in series to the fly-wheel diode (44); and a disconnection signal generator (38) sending a disconnection signal (S5) to the second switching device (42) for a predetermined period after the termination of the drive period (T1). The fly-wheel diode (44) is provided so that a current generated from one end of the exciting coil (14) toward the other end when turning off the first switching device (32) can be recirculated. The second switching device (42) is turned off by the disconnection signal (S5) to be generated with the termination of the drive period (T1) to interrupt the flow of current to the exciting coil (14).







Search report