Method for regulating the current flowing through an electromagnetic actuator
1 Assignment
0 Petitions
Accused Products
Abstract
A method for regulating the current through an electromagnetic actuator. The actuator, a first switch and a current-measuring circuit form a series circuit. A free-wheeling diode is parallel-connected to the actuator. The first switch is closed and opened by a control and a pulse generator using a PWM signal (PWM=pulse width modulation) in such a way that the current flowing through the actuator and measured by the current-measuring circuit is regulated to a setpoint value (SW). The time duration of one on and off switching cycle of the PWM signal is altered, and a so-called dither function in the form of a low-frequency oscillation is superimposed on the PWM signal.
-
Citations
22 Claims
-
1-11. -11. (canceled)
-
12. A method for regulating current through an electromagnetic actuator, the actuator, a first switch and a current-measuring circuit forming a series circuit, a free-wheeling diode being parallel-connected to the actuator, the method comprising:
-
closing and opening the first switch by an automatic control and a pulse generator using a pulse width modulation signal (PWM) in such a way that current flowing through the actuator and measured by the current-measuring circuit is regulated to a setpoint value;
altering a time duration of one on and off switching cycle of the PWM signal; and
superimposing a dither function in a form of a low-frequency oscillation on the PWM signal. - View Dependent Claims (13, 14, 15, 16, 17, 18)
-
-
19. A memory device storing a computer program, the computer program when executed on a computer, causing the computer to perform the following:
-
closing and opening the first switch by an automatic control and a pulse generator using a pulse width modulation signal (PWM) in such a way that current flowing through the actuator and measured by the current-measuring circuit is regulated to a setpoint value;
altering a time duration of one on and off switching cycle of the PWM signal; and
superimposing a dither function in a form of a low-frequency oscillation on the PWM signal. - View Dependent Claims (20)
-
-
21. A control unit for regulating current through an electromagnetic actuator, the actuator, a first switch and a current-measuring circuit forming a series circuit, a free-wheeling diode being parallel-connected to the actuator, and the control unit, comprising:
-
an automatic control; and
a pulse generator by which the first switch (11) is closed and opened using a pulse width modulation (“
PWM”
) signal in such a way that the current flowing through the actuator and measured by the current-measuring circuit is regulated to a setpoint value;
wherein the control unit is configured to alter a time duration of one on and off switching cycle of the PWM signal and superimpose a dither function in a form of a low-frequency oscillation on the PWM signal. - View Dependent Claims (22)
-
Specification