Method and apparatus for reducing the switching noise of an electromagnetic switching device
AssigneeSiemens Aktiengesellschaft
InventorsDirk Hertz, Bernhard Streich
Life of this patent
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Abstract
In order to achieve a reduction in the switching noise during operation of an electromagnetic switching device with little complexity, a coil for moving an armature with moving switching contacts is driven in order to make contact at a first minimum value of a supply voltage. The supply voltage is then increased from the first minimum value to a second minimum value as a function of time, such that the moving switching contacts can be moved with the stationary switching contacts into sufficient mutual contact with pressure applied.
Claims20
A method for reducing the switching noise of an electromagnetic switching device including a coil drivable by a supply voltage, and an armature adapted to move moving switching contacts into contact with stationary switching contacts, the method comprising:
- defining a first minimum value of the supply voltage, sufficient for at least moving the armature with the moving switching contacts;
- using a drive unit to drive the coil, and hence the armature, with the moving switching contacts by the first minimum value of the supply voltage, at least until contact is made;
- and
- increasing, as a function of time, the supply voltage from the first minimum value to a second minimum value, sufficient to move the switching contacts into sufficient mutual contact with the stationary switching contacts with pressure applied;
- wherein the drive unit includes a switching element for driving a voltage limiter;
- and
- wherein the switching element is an optocoupler.
An apparatus for reducing the switching noise of an electromagnetic switching device including a coil drivable by a supply voltage, and an armature adapted to move moving switching contacts into contact with stationary switching contacts, comprising:
- a voltage control unit, adapted to fix the supply voltage, for moving the armature with the moving switching contacts, at least at a sufficient first minimum value;
- and
- a drive unit, adapted to drive the coil with the first minimum value of the supply voltage at least until contact is made, wherein the supply voltage is then adapted to be increased via the voltage control unit, as a function of time, from the first minimum value to a second minimum value, sufficient to move the moving switching contacts into sufficient mutual contact
- wherein the drive unit includes a switching element for driving a voltage limiter;
- and
- wherein the switching element is an optocoupler. with the stationary switching contacts with pressure applied;
An apparatus for reducing the switching noise of an electromagnetic switching device including a coil drivable by a supply voltage, and an armature adapted to move moving switching contacts into contact with stationary switching contacts, comprising:
- voltage control means for fixing the supply voltage to at least at a sufficient first minimum value, sufficient to move the armature with the moving switching contacts;
- and
- driving means for driving the coil with the first minimum value of the supply voltage at least until contact is made, wherein the supply voltage is then increased, as a function of time, via the voltage control means from the first minimum value to a second minimum value, sufficient to move the moving switching contacts into sufficient mutual contact with the stationary switching contacts with pressure applied;
- wherein the driving means includes a switching element for driving a voltage limiter;
- and
- wherein the switching element is an optocoupler.
Dependencies are inferred from the claim text.