CPC G01R 19/16576 (2013.01) [G01R 15/04 (2013.01); G01R 31/52 (2020.01); G01R 31/66 (2020.01); H05B 45/14 (2020.01); H05B 45/50 (2020.01)] | 15 Claims |
1. A voltage sensing circuit for sensing a voltage across a circuit component, comprising:
a first terminal and a second terminal adapted to connect across the circuit component;
a voltage divider including first and second resistors in series, connected in parallel with the circuit component and between the first terminal and the second terminal, wherein a sensing terminal between the first and second resistors is for providing a sense signal that is able to indicate the voltage across the circuit component;
a voltage clamping component coupled from the sensing terminal to the external circuit component;
a current injector for injecting current to the sensing terminal; and
a controller for receiving the sense signal and for controlling the current injection, wherein the controller is adapted to:
detect if the sense signal has dropped below a minimum threshold indicating a fault and in response control the current injector to inject a current into the sensing terminal; and
detect the sense signal in response to the injection of current and in response thereto determine if the fault is caused by the circuit component or by the voltage divider by comparing the sense signal in response to the injected current and a clamping voltage of the voltage clamping component.
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