Control for electrical heating circuit, in particular for motor vehicle
First Claim
1. A method for controlling an electric heating circuit comprising a positive number N of heating elements connected in parallel, each heating element connected in series with an associated electronic switch, the method comprising:
- receiving, by a connector/receiver, a power setpoint in the form of a pulse width modulation (PWM) control signal of variable duty cycle as a function of the power;
transferring, by the connector/receiver, an equivalent PWM signal with the variable duty cycle and a power amplitude, the equivalent PWM signal and the power amplitude being based on a reference voltage supplied by a pull up resistor;
obtaining, by a low-pass RC filter, an average value of the received PWM control signal, the PWM control signal being transferred directly from the connector/receiver to the low-pass RC filter;
comparing, by a positive number P of comparators, the average value of the received PWM control signal to a corresponding positive number P of threshold values;
generating a positive number P of comparison signals based on each of the positive number P of comparisons performed by the positive number P of comparators; and
switching, using the positive number P of comparison signals, a positive number N of electronic switches corresponding to the positive number N of heating elements from an open position to a closed position or from a closed position to an open position,wherein;
P is greater than or equal to 1 and less than or equal to N, andprocessing the PWM control signal, processing the equivalent PWM signal, and controlling the electric heating circuit is performed without using a microcontroller.
1 Assignment
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Accused Products
Abstract
A device (1) for controlling an electrical heating circuit (2) comprising a number N of heating elements (21-23) connected in parallel, comprises, according to the invention: N electronic switches (T1-T3), each able to be connected in series with one of the N heating elements (21-23); a module (10) able to receive a power setpoint in the form of a control signal (PWM) with duty ratio varying as a function of power; means (12) for extracting a mean value (formula (I)) of the control signal (PWM) received; and P comparators (C1-C3), the integer P being less than or equal to N, which are able to compare the mean value (formula (I)) extracted with P distinct threshold values (Ref1-Ref3) and to generate P comparison signals (S1-S3), each comparison signal serving to control a toggling of the electronic switch (T1-T3) associated with at least one heating element into the open or closed position.
19 Citations
8 Claims
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1. A method for controlling an electric heating circuit comprising a positive number N of heating elements connected in parallel, each heating element connected in series with an associated electronic switch, the method comprising:
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receiving, by a connector/receiver, a power setpoint in the form of a pulse width modulation (PWM) control signal of variable duty cycle as a function of the power; transferring, by the connector/receiver, an equivalent PWM signal with the variable duty cycle and a power amplitude, the equivalent PWM signal and the power amplitude being based on a reference voltage supplied by a pull up resistor; obtaining, by a low-pass RC filter, an average value of the received PWM control signal, the PWM control signal being transferred directly from the connector/receiver to the low-pass RC filter; comparing, by a positive number P of comparators, the average value of the received PWM control signal to a corresponding positive number P of threshold values; generating a positive number P of comparison signals based on each of the positive number P of comparisons performed by the positive number P of comparators; and switching, using the positive number P of comparison signals, a positive number N of electronic switches corresponding to the positive number N of heating elements from an open position to a closed position or from a closed position to an open position, wherein; P is greater than or equal to 1 and less than or equal to N, and processing the PWM control signal, processing the equivalent PWM signal, and controlling the electric heating circuit is performed without using a microcontroller. - View Dependent Claims (2, 3)
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4. A device for controlling an electric heating circuit comprising a positive number N of heating elements connected in parallel, the control device comprising:
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a positive number N of electronic switches, each connected in series with one out of the positive number N of heating elements, the positive number N of electronic switches; correspond to the positive number N of heating elements, and switch from an open position to a closed position or from a closed position to an open position based on the positive number P of comparison signals; a connector/receiver that; receives a power setpoint in the form of a pulse width modulation (PWM) control signal of variable duty cycle as a function of the power, and transfers an equivalent PWM signal with the variable duty cycle and a power amplitude, the equivalent PWM signal and the power amplitude being based on a reference voltage supplied by a pull up resistor; a low-pass RC filter, with a time constant greater than a period of the PWM control signal, that obtains an average value of the PWM control signal received directly from the connector/receiver to the low-pass RC filter; a positive number P of comparators that, when P is less than or equal to N; compare the obtained average value with a corresponding positive number P of threshold values, and generate a positive number P of comparison signals based on each of the positive number P of comparisons performed by the positive number P of comparators; and wherein the device processes the PWM control signal, processes the equivalent PWM signal, and controls the electric heating circuit without using a microcontroller. - View Dependent Claims (5, 6, 7)
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8. A method for controlling an electric heating circuit comprising a plurality of heating elements connected in parallel, each heating element connected in series with an associated electronic switch, the method comprising:
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receiving, by a connector/receiver, a pulse width modulation (PWM) control signal of variable duty cycle; transferring, by the connector/receiver, an equivalent PWM signal with the variable duty cycle, an amplitude of the variable duty cycle being based on a reference voltage supplied by a pull up resistor; obtaining, by a low-pass RC filter, an average value of the received PWM control signal, the PWM control signal being transferred directly from the connector/receiver to the low-pass RC filter; comparing, by a plurality of comparators, the average value of the received PWM control signal to a corresponding threshold value, the corresponding threshold value being unique to each comparator out of the plurality of comparators; generating a plurality of comparison signals based on each of the comparisons performed by the plurality of comparators; and switching, using the plurality of comparison signals, a plurality of electronic switches from an open position to a closed position or from a closed position to an open position, each electronic switch out of the plurality of electronic switches corresponding to each heating element out of the plurality of heating elements, wherein; processing the PWM control signal, processing the equivalent PWM signal, and controlling the electric heating circuit is performed without using a microcontroller.
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Specification