Device for controlling at least one electromagnetic load

• US 5,936,827 A
• Filed: 09/02/1997
• Issued: 08/10/1999
• Est. Priority Date: 03/02/1995
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Dressler, Klaus, Tillhon, Engelbert, Schulz, Udo, Werner, Andreas, Koch, Andreas, Burkel, Rainer, Eyberg, Wilhelm, Krampe, Wolfgang
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): HUYNH, KIM NGOC
• Application Number:
  US08/894,803
• Time in Patent Office: 707 Days
• Field of Search: 361/143, 361/152-156, 123/490, 251/234-239
• US Class Current: 361/154
• CPC Class Codes: F02D 2041/2003 using means for creating a boost voltage, i.e. generation or use of a voltage higher than the battery voltage, e.g. to speed up injector opening
• CPC Class Codes: F02D 2041/2006 by using a boost capacitor
• CPC Class Codes: F02D 2041/2017 using means for creating a boost current or using reference switching
• CPC Class Codes: F02D 2041/2058 using information of the actual current value
• CPC Class Codes: F02D 2041/2075 Type of transistors or particular use thereof
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils
• CPC Class Codes: H01F 2007/1822 using a capacitor to produce a boost voltage
• CPC Class Codes: H01F 7/1816 making use of an energy accumulator for relays H01H47/043

Abstract

A device for controlling at least one electromagnetic load, which includes a first switching device arranged between a first terminal of a supply voltage and a first terminal of at least one load, and a second switching device arranged between a first terminal of an assigned load and the second terminal of the supply voltage. The energy released during the transition from a first higher current (IH) to a second lower current (IH) is stored in a storage device.

Claims

1. A device for controlling at least one electromagnetic load having a first load terminal and a second load terminal, the device comprising:

a first switching apparatus coupled between a first voltage terminal of a voltage supply and the first load terminal of the at least one electromagnetic load;

at least one second switching apparatus, each corresponding to a respective load of the at least one electromagnetic load and coupled between a second voltage terminal of the voltage supply and the second load terminal of the respective load;

a free-wheeling diode coupled between the first load terminal of the at least one electromagnetic load and the second voltage terminal of the voltage supply;

a storage unit for storing released energy; and

a controller actuating the at least one second switching apparatus to provide the released energy to the storage unit when a current changes from a starting current value to a holding current value,

wherein, during a first phase, when the current is regulated to a predetermined setpoint value, the controller actuates the first switching apparatus to actuate the free-wheeling diode and reduce the current according to a first decay rate, and

wherein, during a second phase, when the current changes from the starting current value to the holding current value and the actuation of the at least one second switching apparatus provides the released energy to the storage unit, the current is reduced according to a second decay rate that is greater than the first decay rate.

2. The device according to claim 1, wherein the at least one electromagnetic load includes a solenoid valve for controlling a fuel delivery in an internal combustion engine.

3. The device according to claim 1, further comprising:

a third switching apparatus coupling the first load terminal of the at least one electromagnetic load to the storage unit during the first phase.

4. The device according to claim 3, wherein the at least one electromagnetic load includes a plurality of electromagnetic loads divided into at least two groups, and wherein at least one of the first switching apparatus, the third switching apparatus and the storage unit is assigned to each of the at least two groups.

5. The device according to claim 1, wherein, when the at least one second switching apparatus is opened, the released energy is stored in the storage unit.

6. The device according to claim 1, wherein, when the current changes from the holding current value to zero, the released energy is stored in the storage unit.

7. The device according to claim 1, wherein, when the current is regulated to the predetermined setpoint value, the released energy is stored in the storage unit.

8. The device according to claim 1, wherein, during a phase following an activation of the at least one second switching apparatus, the at least one second switching apparatus is controlled by the controller for a predetermined time period occurring during the phase following the activation of the at least one second switching apparatus to prevent the at least one electromagnetic load from activating and to store the released energy in the storage unit.

9. The device according to claim 1, wherein the storage unit is connected in parallel to the at least one second switching apparatus.

10. The device according to claim 1, further comprising:

a current measuring element coupled between the at least one second switching apparatus and the second voltage terminal of the voltage supply, the current measuring element providing a measurement of a current flowing through the at least one electromagnetic load.

11. The device according to claim 10, wherein the current measuring element includes a resistor.