Control circuit between a port of a microprocessor and an actuator and method of maintaining the momentary state of an actuator during a dip in the supply voltage
First Claim
1. A control circuit connected between a control port of a microprocessor and an actuator in a motor vehicle, comprising:
- a control stage having;
a terminal connection connected to an actuator terminal associated with an actuator in a motor vehicle and connected to an electrical system in the motor vehicle for a voltage supply to said control stage, the actuator for performing a function other than driving the motor vehicle;
a control connection connected to a control port of a microprocessor for applying a low level to said control stage from the microprocessor in special cases; and
an output for outputting a control signal to control the actuator in dependence on a voltage level at said terminal connection and said control connection; and
a driver stage connected to said control stage for amplifying the control signal.
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Accused Products
Abstract
A control circuit between a control port of a microprocessor and an actuator has a control stage whose terminal connection is connected to an actuator terminal and whose control connection is connected to the control port of the microprocessor. In normal operation, the control port is switched as an input and, depending on the terminal voltage, the control stage outputs a control signal which is amplified in a driver stage. By switching the control port as an output and applying a low level to the control connection, the control stage can be inhibited in special cases, such as when the supply voltage dips below a given threshold.
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Citations
11 Claims
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1. A control circuit connected between a control port of a microprocessor and an actuator in a motor vehicle, comprising:
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a control stage having;
a terminal connection connected to an actuator terminal associated with an actuator in a motor vehicle and connected to an electrical system in the motor vehicle for a voltage supply to said control stage, the actuator for performing a function other than driving the motor vehicle;
a control connection connected to a control port of a microprocessor for applying a low level to said control stage from the microprocessor in special cases; and
an output for outputting a control signal to control the actuator in dependence on a voltage level at said terminal connection and said control connection; and
a driver stage connected to said control stage for amplifying the control signal. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of maintaining a momentary state of an actuator controlled by a microprocessor during a dip in a supply voltage, which comprises:
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providing an actuator for performing a function other than driving a motor vehicle;
in normal operation, controlling the actuator with a control circuit supplied with voltage via an actuator terminal associated with the actuator; and
therebyoutputting a control signal controlling the actuator with a control stage integrated in the control circuit; and
amplifying the control signal in a driver stage integrated in the control circuit;
in special cases, inhibiting the control stage to prevent output of the control signal by outputting a low level at a control port of the microprocessor; and
in normal operation, processing checking and diagnostic functions with the microprocessor. - View Dependent Claims (8, 9, 10)
reading the voltage level at the output of the driver stage into the microprocessor via a diagnostic line and a diagnostic port;
comparing in the microprocessor the voltage levels read in at the control port and at the diagnostic port; and
if the voltage levels do not match, recognizing a fault function, switching the control port as an output and applying the low level to the control connection of the control stage.
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11. In combination with a microprocessor and an actuator of a motor vehicle for performing a function other than driving the motor vehicle, a control circuit connected between a control port of the microprocessor and the actuator, the control circuit comprising:
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a control stage having a terminal connection connected to an actuator terminal associated with the actuator and connected to an electrical system of the motor vehicle for a voltage supply to said control stage;
a control connection connected to the control port of the microprocessor for applying a low level to said control stage from the microprocessor in special cases; and
an output for outputting a control signal to control the actuator in dependence on a voltage level at said terminal connection and said control connection; and
a driver stage connected to said control stage for amplifying the control signal.
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Specification