Electric grill with current protection circuitry
AssigneeWeber-Stephen Products LLC
InventorsEric Knappenberger, Julio C. Zuleta, Matthew Lerch, Jeffery C. Emmerich
Life of this patent
Estimating the term…
Abstract
Provided is an apparatus and method for protecting against unsafe electric current conditions. A protections circuit may be used in a device, such as an electric grill, that has one or more electric loads, such as heating elements. The protection circuit may protect against various failure scenarios, including, without limitation, instances of ground fault, over current, driver failure, and failure of a microprocessor. In response to a failure, the protection circuit may trip a latch relay or disable a triac driver to stop current from flowing.
Claims20
An electric grill, comprising:
- a heating element connected to a voltage line through a triac, the heating element further connected to a neutral line;
- a trip controller in communication with a latch, the latch connected between the heating element and the voltage line;
- a current sensor to measure current delivered to the heating element;
- and
- logic circuitry in communication with the trip controller and the current sensor, wherein the logic circuitry is to:
- receive a current measurement from the current sensor;
- access an expected current associated with a selected operating mode;
- select a current threshold based on the expected current associated with the selected operating mode, the current threshold being less than the expected current;
- cause the trip controller to disable the latch in response to the current reading from the current sensor being less than the current threshold;
- and
- cause, in response to the disabling of the latch, presentation of an alert to indicate that the latch has been disabled.
An electric circuit for operating and protecting an electric grill, the electric circuit comprising:
- a heating element;
- a latch to disable a flow of current to the heating element;
- a current sensor to measure the current delivered to the heating element;
- and
- a microprocessor connected to a triac, the triac connected between a voltage line and the heating element such that the microprocessor is to control the heating element by activating the triac, wherein the microprocessor is to:
- receive the measured current from the current sensor;
- access a selected high, medium, or low operating mode from a user input device;
- determine an expected current associated with the selected high, medium, or low operating mode;
- select a current threshold based on the expected current associated with the selected high, medium, or low operating mode, the current threshold being less than the expected current;
- cause the latch to become disabled in response to the measured current being less than the current threshold;
- and
- cause, in response to the current being less than the current threshold, presentation of an alert to indicate that the heating element has been disabled.
An electric grill, comprising:
- a heating element;
- a user input to select an operating mode of the heating element;
- at least one latch relay connected between the heating element and a voltage line, the latch relay to selectively disable a flow of current to the heating element;
- a microprocessor connected to a triac driver, the triac driver in communication with the triac, wherein the microprocessor is to activate the triac driver to deliver a current associated with the selected operating mode;
- and
- a current sensor to measure current passing through the triac, the current sensor to provide a measured current to the microprocessor, wherein the microprocessor is further to:
- access the measured current from the current sensor;
- access a memory to retrieve an expected current threshold associated with a selected high, medium, or low operating mode of the heating element, the expected current threshold being less than an expected current associated with the selected high, medium, or low operating mode of the heating element;
- compare the measured current with the expected current threshold for the selected high, medium, or low operating mode;
- disable the flow of current to the heating element in response to a measured current that is less than the expected current threshold;
- and
- cause presentation of an alert to indicate that the flow of current has been disabled.
Dependencies are inferred from the claim text.