Circuit for detecting a short circuit in a low side driven load
AssigneeChrysler Corporation
InventorRobert T. Arntz
Life of this patent
Estimating the term…
Abstract
A circuit is provided for detecting a short circuit in a remote low-side driven load wherein a single conductor is used to both transmit a control signal from a microprocessor controller through a local driver to the remote driver of the load and also to transmit fault signals from the remotely driven load back to the control means. A control signal is transmitted from the microprocessor controller through a local driver circuit to a remote driver circuit on a single conductor. A short circuit at the remote load causes a fault signal to be latched for later detection by the microprocessor and a short circuit at the local driver is immediately detected.
Claims14
A circuit for driving one side of a load that has its other side electrically connected to a first voltage source, and for providing short circuit detection, comprising:
- a control circuit that provides control pulse signals over a single conductor;
- a remote driver with an input connected to the single conductor and an output connected to the one side of the load and a disable terminal for controlling the state of said remote driver, said remote driver connecting the one side of the load to a low level compared to the first voltage in response to the control signals provided to the input over the single conductor;
- a short circuit detector that compares the remote driver output with a reference voltage so as to detect a short circuit between the first voltage source and the remote driver output, said short circuit detector provides a short circuit detection signal in response to the comparison, said detection signal being applied to the disable terminal of the remote driver as a result of detecting the short circuit;
- and
- a high voltage circuit with an output connected to the single conductor, said detection signal being effective to cause said high voltage circuit to provide a high voltage signal on the single conductor at the termination of the control pulse signal.
A circuit for driving one side of a load that has its other side electrically connected to a first voltage source, and for providing short circuit detection,
- a control circuit that provides control pulse signals over a single conductor, the control circuit comprising
- a microprocessor that generates the control pulse signals,
- a local driver receiving control pulse signals from the microprocessor and having an output connected to the single conductor, said local driver connects the single conductor to a low level compared to the first voltage in response to the control pulse signals, and
- a fault detector which compares the signal on the single conductor to a certain reference voltage to detect the short circuit between the single conductor and a voltage source, said fault detector providing a fault signal that turns off said local driver;
- a remote driver with an input connected to the single conductor and an output connected to the one side of the load and a disable terminal for controlling the state of said remote driver, said remote driver connecting the one side of the load to a low level compared to the first voltage in response to the control signals provided to the input over the single conductor;
- a short circuit detector that compares the remote driver output with a reference voltage so as to detect a short circuit between the first voltage source and the driver output, said short circuit detector provides a short circuit detection signal in response to the comparison, said detection signal being applied to the disable terminal of the remote driver as a result of detecting the short circuit;
- and
- a high voltage circuit with an output connected to the single conductor, said high voltage circuit providing a high voltage on the single conductor at the termination of the control pulse signal in response to the short circuit detection signal;
- and
- a memory that receives the short circuit detection signal and stores a fault condition pending termination of the control signal pulses, the fault condition in said memory being effective to operate said high voltage circuit.
Dependencies are inferred from the claim text.