Driving Circuit Load Connection Detection
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Solution Overview
Problem
Existing methods for detecting incorrectly connected loads in electric systems are unsatisfactory due to increased circuit complexity and leakage, and they do not provide accurate detection of open load conditions.
Innovation Solution
A driving circuit that includes a switchable power electronic device, a current generator, and an electric voltage comparator, along with a diagnostics block that uses a current generator and diode to detect the connection status of the load by comparing the load's voltage to a reference voltage, providing a detection signal indicative of correct or incorrect connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sensing resistor and operational amplifier are used to directly measure load current, then detection accuracy is improved, but circuit complexity and leakage increase
Solution Approach 1:
The patent extracts the detection function from the main power circuit by using a separate diagnostics block that operates during the off-state of the power transistor. This allows current detection without requiring sensing resistors in the main power path, reducing circuit complexity while maintaining detection accuracy.
Solution Approach 2:
The patent introduces an intermediary current generator that creates a reference current during the off-state, which is then compared with the actual load current. This intermediary mechanism enables accurate detection without directly measuring the main load current through complex sensing circuits.
2Measurement precision
If current mirror and additional driving circuit are used for indirect current measurement, then detection capability is improved, but circuit complexity increases
Solution Approach 1:
The patent merges the detection function with the existing power circuit timing by utilizing the off-state of the power transistor for diagnostics. The diagnostics block is activated during the same off-period that the power transistor is non-conducting, combining two functions into one time window without requiring separate additional driving circuits.
Solution Approach 2:
The system uses its own off-state period to perform self-diagnostics. The power transistor's natural switching cycle provides the opportunity for the diagnostics block to measure current without requiring external or additional driving circuits, making the system self-sufficient for detection purposes.
3Measurement precision
If additional detection components are added to the circuit, then detection accuracy is improved, but leakage current increases
Solution Approach 1:
The patent implements periodic detection by activating the diagnostics block only during the off-state periods of the power transistor. This periodic action allows accurate current measurement without continuously energizing additional detection components, thereby minimizing leakage current while maintaining detection accuracy when needed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution accurately detects load connection conditions without excessive circuit complexity or leakage, enabling timely alerts for incorrect connections and maintaining normal system operation without restrictive restraints.
Implementation Method 1
a diode D, having an anode connected to the second node and a cathode connected to the first node, which is caused to conduct
Implementation Method 2
an electric voltage comparator, having a first input connected to the first node and a second input connected to a reference voltage source
Data Source
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AI summary
An electronic circuit (100) is disclosed, comprising a node (EX), which connectable to a load (LD) to be driven and a power device (PD), which can be switched between activation and deactivation and having a first terminal connected to said node. The circuit further comprises: a current generator (I) having an output connected to said node and that can be enabled to generation, at least when the power device is deactivated; a comparator (CP) of an electric voltage of said node (V(EX)) with a reference voltage (V(REF)) configured to obtain comparison signals (RESETN), from which distinct conditions of electric connection of the load to said node will be detected.