Energizing method for a single phase timepiece stepping motor
AssigneeOmega SA
InventorMai Tu Xuan
Life of this patent
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Abstract
An energizing method for a timepiece stepping motor provides just sufficient energy to the motor winding to assure a single step of the rotor with each driving pulse. With each pulse the winding is initially energized at a constant voltage (period T.sub.1) then at a constant current (period T.sub.2) between two limits Imax and Imin. When the time period .DELTA.T.sub.3 required for the current to pass from Imax to Imin is greater than a reference time period .DELTA.T.sub.ref. the energization is terminated. The invention may be employed in a wristwatch with the purpose of reducing energy consumption and increasing battery life.
Claims12
Method of energizing a single phase timepiece stepping motor wherein the motor winding receives with each driving pulse just sufficient energy to assure a single rotor step, said motor exhibiting a positioning couple Ca, a drag couple Cr and a magnet-to-winding coupling factor k, comprising the following steps:
- applying a predetermined voltage of constant amplitude to the motor winding during a first predetermined time period T.sub.1 to drive said motor in one direction;
- following said first time period causing a substantially constant current to flow through the motor winding during a second time period of a predetermined maximum duration T.sub.2 at the end of which the rotor will have reached an angular position such as to assure completion of its step, said substantially constant current being applied to said motor winding in a sense to drive said motor in said one direction;
- and
- interrupting energization of the winding at the end of said second time period.
Method of energizing a single phase timepiece stepping motor wherein the motor winding receives with each driving pulse just sufficient energy to assure a single rotor step, said motor exhibiting a positioning couple Ca, a drag couple Cr and a magnet-to-winding coupling factor k, comprising the following steps:
- applying a predetermined voltage at the motor winding during a first predetermined time period T.sub.1 ;
- following said first time period applying to the motor winding a substantially constant current during a second time period of a predetermined maximum duration T.sub.2 at the end of which the rotor will have reached an angular position such as to assure completion of its step;
- during said second time period detecting if and when the coupling factor k changes sign, the instant td of such detection indicating that the rotor has reached said angular position;
- and
- interrupting energization of the winding at said instant td.
Method of energizing a single phase timepiece stepping motor wherein the motor winding receives with each driving pulse just sufficient energy to assure a single rotor step, said motor exhibiting a positioning couple Ca, a drag couple Cr and a magnet-to-winding coupling factor k, comprising the following steps:
- applying a predetermined voltage comprising a series of regularly spaced pulses of constant amplitude to the motor winding during a first predetermined time period T.sub.1 to drive said motor in one direction;
- following said first time period causing a substantially constant current to flow through the motor winding during a second time period of a predetermined maximum duration T.sub.2 at the end of which the rotor will have reached an angular position such as to assure completion of its step, said substantially constant current being applied to said motor winding in a sense to drive said motor in said one direction;
- and
- interrupting energization of the winding at the end of said second time period.
Dependencies are inferred from the claim text.