Circuit configuration for charging and discharging a plurality of capacitive actuators

• US 7,336,018 B2
• Filed: 01/26/2005
• Issued: 02/26/2008
• Est. Priority Date: 01/26/2004
• Status: Expired due to Fees

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Augesky, Christian Georg
• Primary Examiner(s): Dougherty; Thomas M.
• Application Number:
  US11/043,321
• Publication Number:
  US 20050231170A1
• Time in Patent Office: 1,126 Days
• Field of Search: 310/316.03, 310/317
• US Class Current: 310/316.03
• 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 2041/2041 for controlling the current in the free-wheeling phase
• CPC Class Codes: F02D 2041/2058 using information of the actual current value
• CPC Class Codes: F02D 41/2096 for controlling piezoelectric injectors drive and control circuit for piezoelectric devices in general H10N30/802
• CPC Class Codes: F02M 51/0603 using piezoelectric or magnetostrictive operating means
• CPC Class Codes: H02N 2/067 generating drive pulses

Abstract

A circuit is provided for charging and discharging a plurality of capacitive actuators, which can be produced with little component outlay and minimizes power loss. The circuit has a charge capacitor, which is charged to a charge voltage predefined in relation to a reference potential, and charge circuits for charging one of the capacitive actuators in each instance which are connected parallel to the charge capacitor and in each of which one of the capacitive actuators is disposed in a series circuit with a choke and a selector/charge switch. The charge circuits have a common charge circuit section containing the choke. Discharge circuits are provided for discharging one of the capacitive actuators in each instance, which are connected parallel to the series circuits formed by the choke and the capacitive actuators and a discharge switch. The discharge circuits having a common discharge circuit section containing the discharge switch.

Claims

1. A circuit configuration for charging and discharging a plurality of capacitive actuators in a fuel injector configuration in an internal combustion engine of a vehicle, the circuit configuration comprising:

an energy source;

a charge capacitor connected to and charged by said energy source to a charge voltage predefined in relation to a vehicle ground, the charge voltage being selected as negative in relation to the vehicle ground;

charge circuits each for charging one of the capacitive actuators, said charge circuits each connected parallel to said charge capacitor, said charge circuits having a common charge circuit section containing a choke and a plurality of charge circuit sections configured parallel to each other and corresponding to a number of the capacitive actuators, said charge circuit sections each having a selector/charge switch, in each of said charge circuits one of the capacitive actuators is disposed in a series circuit with said choke and said selector/charge switch, each of said charge circuit sections having said selector/charge switch connected in series to one of the capacitive actuators;

discharge circuits each for discharging one of the capacitive actuators, said discharge circuits having a common discharge circuit section containing a discharge switch and a plurality of discharge circuit sections configured parallel to each other and corresponding to the number of the capacitive actuators, said discharge circuits each connected parallel to a series circuit formed by said choke and one of the capacitive actuators, each of said discharge circuit sections having a decoupling diode; and

a sensing resistor for measuring current flowing via the capacitive actuators during charging and discharging, said sensing resistor disposed in a series circuit with said choke such that said choke forms part of said common charge circuit section and said common discharge circuit section, said sensing resistor having a terminal connected to the vehicle ground.

2. The circuit configuration according to claim 1, wherein each of said charge circuit sections having a freewheeling charge path containing a freewheeling diode being formed in each instance between said choke and each of the capacitive actuators.