Electrontic barrier device for intrinsically safe systems
AssigneeEaton Intelligent Power Limited
InventorFrederic Vladimir Esposito
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Abstract
An electronic barrier device includes an Isolating Barrier or a Zener Barrier with a voltage limiter or voltage shunt such as at least one zener device for voltage limitation in a circuit during a fault condition. The barrier device includes a crowbar device arranged to latch across the at least one voltage shunt device to reduce power dissipation in the at least one voltage shunt device in the circuit fault condition. The crowbar device is arranged to latch responsive to a change in a current flowing in the barrier device.
Claims19
An electronic barrier device comprising:
- an input;
- a voltage limiter device for voltage limitation in a circuit during a circuit fault condition,
- a crowbar device arranged to latch across the voltage limiter device to reduce power dissipation in the voltage limiter device in the circuit fault condition,
- a current sensor connected between the input and the crowbar device such that the current sensor is disposed upstream from the crowbar device, the current sensor sensing current at the input, and
- a fuse disposed between the input and the current sensor such that the sensed current comprises a current through the fuse, the current sensor being disposed between the fuse and the crowbar device,
- wherein the crowbar device is arranged to automatically latch responsive to a change in the current sensed by the current sensor thereby increasing the current through the current sensor in the circuit fault condition, the electronic barrier device being configured for use in intrinsically safe systems.
A crowbar device arranged to latch across a voltage limiter device of a barrier device to reduce power dissipation in the voltage limiter device,
- wherein the crowbar device is arranged downstream from a current sensor to automatically latch responsive to a change in a current sensed by the current sensor thereby increasing the current through the current sensor in a circuit fault condition, the current sensor being connected between an input of the barrier device and the crowbar device, and a fuse of the barrier device being disposed between the input and the current sensor such that the sensed current comprises a current through the fuse, the current sensor being disposed between the fuse and the crowbar device, the crowbar device being configured for use in the barrier device, and the barrier device being configured for use in intrinsically safe systems.
A method of reducing power dissipation in a voltage-limiter of a barrier device during a circuit fault condition, including the step of:
- sensing a change in current in the barrier device flowing across a current sensor, and
- automatically latching a crowbar device, disposed downstream from the current sensor, across the voltage limiter to reduce the power dissipation in response to the sensing of the change in current across the current sensor thereby increasing the current through the current sensor in the circuit fault condition, the current sensor being connected between an input of the barrier device and the crowbar device, and
- wherein the step of sensing the change in current includes sensing the change in current through a fuse device of the barrier device, the fuse device being disposed between the input and the current sensor, and the current sensor being disposed between the fuse device and the crowbar device.
Dependencies are inferred from the claim text.