Method and configuration for driving a capacitive actuator
AssigneeSiemens Aktiengesellschaft
InventorsChristian Hoffmann, Hellmut Freudenberg, Hartmut Gerken
Life of this patent
Estimating the term…
Abstract
In a driving configuration for driving an actuator, component tolerances are compensated for by measuring a discharging current flowing in a measuring branch and the discharging voltage during a charge-transfer (reversing) operation. The measuring branch contains a series resonance circuit having a charging capacitor, a coil, an auxiliary switch and a measuring resistor. The current and voltage values measured at various instants are evaluated; and from them, initial parameters are determined for the subsequent driving operations.
Claims11
A method for driving a capacitive actuator being driven by a driving circuit having a series resonance circuit with a charging capacitor and a coil, the method compensating for component tolerances of the driving circuit, which comprises:
- reversing a charge of the charging capacitor previously charged to a predetermined calibrating voltage, via the coil and detecting current values of a flowing charge-transfer current at different instants;
- determining a charging capacitance of the charging capacitor and an inductance of the coil from the predetermined calibrating voltage, the different instants and the current values with an aid of laws applicable in series resonance circuits;
- determining a starting voltage and a charging time from a predeterminable energy, the charging capacitance and the inductance on a basis of characteristic maps;
- and
- transferring the predeterminable energy to the capacitive actuator by the charging capacitor charged to the starting voltage and having its charge transferred during the charging time to the capacitive actuator.
A driving circuit that self-compensates for component tolerances of components of the driving circuit, comprising:
- a series circuit having a charging capacitor with a charging capacitance, a coil having an inductance disposed in series with said charging capacitor, and an adjuster circuit disposed in series with said coil and having an actuator;
- a main switch connected to said charging capacitor and to be connected to an energy source for supplying said charging capacitor via said main switch;
- a switching branch disposed in parallel with said adjuster circuit of said series circuit and having an auxiliary switch and a measuring resistor connected to said auxiliary switch;
- said charging capacitor, said coil and said switching branch forming a measuring branch;
- and
- a controller connected to said series circuit and said main switch for performing the following operating steps:
- reversing a charge of said charging capacitor, previously charged to a predetermined calibrating voltage, via said coil and detecting current values of a flowing charge-transfer current at different instants;
- determining said charging capacitance of said charging capacitor and said inductance of said coil from the predetermined calibrating voltage, the different instants and the current values with an aid of laws applicable in series resonance circuits;
- determining a starting voltage and a charging time from a predeterminable energy, said charging capacitance and said inductance on a basis of characteristic maps;
- and
- transferring the predeterminable energy to said actuator by said charging capacitor charged to the starting voltage and having its charge transferred during the charging time to said actuator.
Dependencies are inferred from the claim text.