Isolated voltage detection with current limiters
AssigneeB/E Aerospace, Inc.
InventorDennis Mulders
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Abstract
A circuit comprises an optical coupling including an illuminator optically coupled to an optical sensor to output a voltage from the optical sensor based on intensity of illumination from the illuminator. The circuit includes a voltage input node with a resistance connected in series between the voltage input and a Zener diode. A method includes powering an illuminator with current from a first voltage input node. The method includes sensing illumination level in illumination from the illuminator with a sensor and outputting output proportionate to illumination sensed by the sensor indicative of voltage detected at the voltage input node. The method can include limiting current between the voltage input node and the illuminator.
Claims12
A circuit comprising:
- an optical coupling including an illuminator optically coupled to an optical sensor to output a voltage from the optical sensor based on intensity of illumination from the illuminator;
- a voltage input node with a resistance connected in series between the voltage input and a Zener diode oriented to block current from the voltage input node through the resistance below a threshold voltage, and to allow current from the voltage input node through the resistance above the threshold voltage, wherein the Zener diode is operatively connected to the illuminator to power the illuminator;
- and
- a current limiter connected between the voltage input node and the Zener diode to provide consistent current to the illuminator above the threshold voltage, wherein the current limiter includes a switching component with a drain connected to the voltage input node, a source connected to a first node in series between the Zener diode and the resistance, and a gate connected to a second node in series between the resistance and the first node, wherein the Zener diode is a first Zener diode and further comprising a second Zener diode in series between the first and second nodes, wherein the second Zener diode is oriented in the same direction with respect to the voltage input node as is the first Zener diode.
A method of voltage detection in an aircraft oven comprising:
- powering an illuminator with current from a first voltage input node;
- sensing illumination level in illumination from the illuminator with a sensor and outputting output proportionate to illumination sensed by the sensor indicative of voltage detected at the voltage input node, wherein powering the illuminator includes limiting current between the voltage input node and the illuminator, wherein limiting current includes using a switching component with a drain connected to the voltage input node, a source connected to a first node in series between a Zener diode and a resistance, and a gate connected to a second node in series between the resistance and the first node, wherein the Zener diode is a first Zener diode and further comprising a second Zener diode in series between the first and second nodes, wherein the second Zener diode is oriented in the same direction with respect to the voltage input node as is the first Zener diode.
Dependencies are inferred from the claim text.