Method for checking the function of at least one PTC heating element
AssigneeContinental Automotive GmbH
InventorsPeter Bauer, Jan Hodgson
Life of this patent
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Abstract
The invention relates to a method for checking the function of at least one PTC heating element which is used in a device for providing a liquid additive. The at least one PTC heating element is connected to a voltage source via electric conductors. According to the method, a starting current with a first value is provided at a specified operating voltage in a step a). Then, in a step b), a monitoring process is carried out in order to determine whether the starting current with the first value is provided for a minimum duration, said minimum duration having a value of at least seconds. The method is used in particular for on-board diagnoses of a device for providing a liquid additive.
Claims9
A method for checking the function of at least one Positive Temperature Coefficient (PTC) heating element which is used in a device for providing a liquid additive, comprising the steps of:
- providing at least one PTC heating element;
- providing a voltage source, the voltage source being connected to the at least one PTC heating element via electric conductors;
- providing a first value of current;
- providing a switch-on current equivalent to the first value of current at a predetermined operating voltage;
- providing a minimum duration of time;
- and
- monitoring whether the switch-on current with the first value is provided for the minimum duration of time, wherein the minimum duration is at least five seconds;
- detecting a malfunction of the at least one PTC heating element if the switch-on current undershoots the first value during the minimum duration.
A device for providing a liquid additive, comprising:
- at least one Positive Temperature Coefficient (PTC) heating element which is configured to melt frozen liquid additive in the device, the device is being connected to a monitoring unit;
- a voltage source, the voltage source being connected to the at least one PTC heating element via electric conductors;
- a first value of current;
- a switch-on current equivalent to the first value of current at a predetermined operating voltage;
- and
- wherein the switch-on current is monitored to determine if the switch-on current is provided for at least five seconds, and a malfunction of the at least one PTC heating element is detected if the switch-on current undershoots the first value during the at least five seconds.
Dependencies are inferred from the claim text.