Intrinsically Safe Voltage Clamping Device
AssigneeFisher Controls International LLC
InventorStephen G. Seberger
Life of this patent
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Abstract
An intrinsically safe voltage clamping device includes a regulated rail, a ground rail, and a shunt regulator assembly. The shunt regulator assembly is coupled to both the regulated rail and the ground rail and includes one or more regulating components. The shunt regulator assembly is configured to clamp a voltage applied across the regulated rail and the ground rail to a safety clamp voltage value. The intrinsically safe voltage clamping device also includes a power-sensing component configured to cause one or more limiting components to reduce a power dissipated in the respective regulating components without raising the clamp voltage.
Claims25
An intrinsically safe voltage clamping device comprising:
- a regulated rail;
- a ground rail;
- a shunt regulator assembly coupled to both the regulated rail and the ground rail and including one or more regulating components, the shunt regulator assembly configured to clamp a voltage applied across the regulated rail and the ground rail to a safety clamp voltage value;
- and
- a power-sensing component comprising:
- (1) a thermally activated component configured to, when a temperature of at least one of the regulating components exceeds a threshold value, cause one or more limiting components to reduce a power dissipated in the at least one of the regulating components, or
- (2) a current-sensing resistor configured to, when the current through the resistor exceeds a threshold value, cause one or more limiting components to reduce a power dissipated in the at least one of the regulating components.
A process control device comprising:
- a device component having first and second terminals, the device component storing energy when a voltage is applied across the first and second terminals of the device component;
- two or more voltage clamping devices electrically coupled to the device component, each voltage clamping device disposed in parallel with the other of the voltage clamping devices, and each voltage clamping device configured to clamp the voltage applied across the device component to a safety clamp voltage, each voltage clamping device comprising:
- a shunt regulator assembly including one or more regulating components, and
- a power-sensing component configured to, when a temperature or current exceeds a threshold value, cause one or more limiting components to reduce a power dissipated in the at least one of the regulating components.
A voltage clamping device comprising:
- a regulated rail;
- a ground rail;
- a shunt regulator assembly including one or more regulating components and, configured to clamp a voltage applied across a regulated rail and a ground rail to a safety clamp voltage value;
- and
- a power-sensing component configured to cause one or more limiting components to reduce a power dissipated in the at least one of the regulating components.
Dependencies are inferred from the claim text.