Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L1/00—Supplying electric power to auxiliary equipment of vehicles
  • B60L1/02—Supplying electric power to auxiliary equipment of vehicles to electric heating circuits
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60H—ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES
  • B60H1/00—Heating, cooling or ventilating [HVAC] devices
  • B60H1/22—Heating, cooling or ventilating [HVAC] devices the heat being derived otherwise than from the propulsion plant
  • B60H1/2215—Heating, cooling or ventilating [HVAC] devices the heat being derived otherwise than from the propulsion plant the heat being derived from electric heaters
  • B60H1/2218—Heating, cooling or ventilating [HVAC] devices the heat being derived otherwise than from the propulsion plant the heat being derived from electric heaters controlling the operation of electric heaters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L3/00—Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption
  • B60L3/0023—Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
  • B60L3/0069—Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train relating to the isolation, e.g. ground fault or leak current
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L3/00—Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption
  • B60L3/04—Cutting off the power supply under fault conditions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L58/00—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles
  • B60L58/10—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries
  • B60L58/18—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules
  • B60L58/20—Methods or circuit arrangements for monitoring or controlling batteries or fuel cells, specially adapted for electric vehicles for monitoring or controlling batteries of two or more battery modules having different nominal voltages
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R16/00—Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for
  • B60R16/02—Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for electric constitutive elements
  • B60R16/03—Electric or fluid circuits specially adapted for vehicles and not otherwise provided for; Arrangement of elements of electric or fluid circuits specially adapted for vehicles and not otherwise provided for electric constitutive elements for supply of electrical power to vehicle subsystems or for
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60H—ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES
  • B60H1/00—Heating, cooling or ventilating [HVAC] devices
  • B60H1/22—Heating, cooling or ventilating [HVAC] devices the heat being derived otherwise than from the propulsion plant
  • B60H2001/2228—Heating, cooling or ventilating [HVAC] devices the heat being derived otherwise than from the propulsion plant controlling the operation of heaters
  • B60H2001/2231—Heating, cooling or ventilating [HVAC] devices the heat being derived otherwise than from the propulsion plant controlling the operation of heaters for proper or safe operation of the heater
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H3/00—Air heaters
  • F24H3/02—Air heaters with forced circulation
  • F24H3/04—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element
  • F24H3/0405—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between
  • F24H3/0429—For vehicles
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/005—Testing of electric installations on transport means
  • G01R31/006—Testing of electric installations on transport means on road vehicles, e.g. automobiles or trucks
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
  • G01R31/52—Testing for short-circuits, leakage current or ground faults
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02T90/10—Technologies relating to charging of electric vehicles
  • Y02T90/16—Information or communication technologies improving the operation of electric vehicles

Definitions

• the present invention relates to an electric heater for a motor vehicle adapted to be supplied with voltage by a first power supply network and a second power supply network.
• the electric heating device comprises a communication bus on which heating instructions can be sent to it and a connection interface with each power supply network.
• the communication bus is powered by the same power supply network as the control elements.
• a disadvantage of this state of the art is that if a problem such as a short circuit occurs in the functional module comprising said control elements, there is a risk that the high voltage supplied by the high power power network is found on the connection interface connected to the low-power power supply network and on the communication bus, creating a dangerous voltage, so-called overvoltage, which may damage them.
• the present invention aims to solve the aforementioned drawback.
• the invention proposes an electric heating device for a motor vehicle adapted to be supplied with voltage by a first power supply network and by a second power supply network, according to which the electric heating device comprises:
• a main switch connected to the functional module adapted to pass signals on the communication bus;
• the electric heating device may further comprise one or more additional characteristics among the following:
• the first protection module comprises:
• an overvoltage detection module comprising:
• a first protective switch adapted to close when the protective diode becomes conducting
• a secondary switch adapted to open when said overvoltage exists so as to open the main switch
• a second protective switch adapted to open when the first protective switch closes so as to open the secondary switch.
• the opening of the secondary switch avoids having currents flowing from the second power supply network to the first power supply network. This makes it possible to protect the communication bus against an overvoltage.
• the signals are low logic signals.
• the low logic signals are 0 volt signals.
• the electric heating device further comprises a main anti-return diode adapted to prevent a current from flowing to the first power supply network when the main switch is open. This protects the first power supply network.
• the electric heating device further comprises a secondary non-return diode adapted to prevent a current from flowing in the second protective switch. This protects said second protective switch.
• the electric heating device further comprises a main return resistance adapted to ensure the opening of the main switch when said overvoltage.
• the electric heating device further comprises a secondary resistor adapted to ensure the opening of the secondary switch when said overvoltage.
• the electric heating device further comprises a base resistor adapted to ensure the closure of the secondary switch when a current flows in said secondary switch.
• the electric heating device further comprises a self-resetting fuse adapted to protect the communication bus against an overcurrent. This makes it possible to protect said communication bus.
• the electric heating device further comprises a tertiary anti-return diode adapted to ensure that the main switch remains open.
• the electric heating device further comprises a protective diode adapted to protect the main switch against an increase in the voltage of the first power supply network. This prevents it from being damaged.
• the electric heating device further comprises an additional protective diode adapted to protect the secondary switch against a voltage inversion. This prevents it from being damaged by a negative voltage.
• the first power supply network is adapted to provide a voltage lower than a voltage supplied by the second power supply network.
• the first power supply network is adapted to provide a voltage of 12Volts.
• the second power supply network is adapted to provide a voltage of 48Volts.
• the communication bus is a LIN bus or a PWM bus.
• a LIN bus allows you to use only one wire for sending and receiving signals. Thus, only one wire is used for two different functions, namely a diagnostic function and a setpoint function. It is also possible to use any other type of communication bus that makes it possible to have bidirectional communication.
• a PWM bus is used to receive or send signals with a controlled duty cycle.
• the functional module comprises a control module adapted to be supplied with voltage by the first power supply network and to receive and / or transmit signals via the communication bus.
• the functional module can thus exchange information with another electronic device via its control module. It can send diagnostic information and receive set information.
• the functional module comprises at least one resistive heating element connected to the first connection interface and at least one associated control element connected to the second connection interface, said control element being adapted to drive said resistive heating element.
• said control element is adapted to control the current of said resistive heating element.
• the first connection interface and the second connection interface are connected to a common ground
• the electric heating device furthermore comprises, in addition, a second protection module adapted to isolate the first network. power supply and the communication bus of the second power supply network during a loss of the common ground.
• the second protection module comprises:
• the first protection module is used to protect the first network and the communication bus against a common ground loss. This reduces the costs and complexity of the architecture of the electric heater 1 for the protections.
• the invention also applies to an air blower for a motor vehicle.
• an air blower for a motor vehicle adapted to be supplied with voltage by a first power supply network and by a second power supply network, according to which the blower Air includes:
• connection interface with a communication bus
• functional module connected to the first connection interface and to the second connection interface
• a main switch connected to the functional module adapted to pass signals on the communication bus; a first protection module adapted to isolate the first power supply network and the communication bus from the second power supply network when there is an overvoltage between the functional module and the first connection interface and the third connection interface; .
• FIG. 1 represents a diagram according to a non-limiting embodiment of the invention of an electric heating device for a motor vehicle, said electric heating device being powered by a first and a second power supply network, and connected to a communication bus and comprising a first overvoltage protection module and a second protection module against a mass partition;
• FIG. 2a shows a diagram of the electric heater of Figure 1 with the detail of the electronic components of the first protection module according to a non-limiting embodiment
• FIG. 2b shows a diagram of the electric heater of Figure 1 with the detail of the electronic components of the second protection module according to a non-limiting embodiment
• FIG. 3 shows a diagram of the electric heater of Figure 1 when there is a short circuit in the second power supply network according to a non-limiting embodiment
• FIG. 4 represents a diagram of the electric heating device of FIG. 1 when the mass is lost according to a nonlimiting embodiment
• FIG. 5 represents a diagram of the electric heating device of FIG. 1 when it receives signals from another electronic device, according to a nonlimiting embodiment
• FIG. 6 shows a diagram of the electric heater of Figure 1 when it sends signals to another electronic device, according to a non-limiting embodiment.
• motor vehicle we mean any type of motorized vehicle.
• the electric heating device 1 is supplied with voltage by a first power supply network G12 and a second power supply network G48.
• the electric heating device 1 comprises:
• a second I48 connection interface with the second G48 power supply network a third ILW connection interface with a BLW communication bus
• a functional module 1 1 connected to the first connection interface 112 and to the second connection interface I48;
• a main switch Q2 connected to the functional module 1 1 and adapted to pass DAT signals on the communication bus BLW;
• a first protection module 10 adapted to isolate the first power supply network G12 and the communication bus BLW from the second power supply network G48 when there is an overvoltage USS between the functional module 1 1 and the first interface of connection 112 and the third ILW connection interface.
• the electric heater 1 is part of a NLW communication network.
• a USS overvoltage appears between the functional module 1 1 and the first connection interface 112, and between the functional module 1 1 and the third connection interface ILW, when there is a short circuit CC in the functional module 1 1.
• Such a short circuit CC is taken as a non-limiting example in the following description.
• a DC short circuit in the functional module 1 1 will also be simply cited as short circuit DC. It will be noted that when a DC short circuit occurs in the functional module 1 1, it means that the elements of the functional module 1 1 whose DLW control module will be defective are destroyed.
• the first protection module 10 - the BLW communication bus.
• the main anti-return diode D8 and the first protection module 10 protect these elements against said currents and voltages.
• the first protection module 10 will make it possible to isolate the first connection interface 112 and the third connection interface ILW and consequently the communication bus BLW with a dangerous voltage, namely the said overvoltage USS.
• these interfaces which are dimensioned for a low voltage power supply G12 network (here 12V) can not withstand a voltage too large, for example greater than 40V.
• the first protection module 10 comprises:
• an overvoltage detection module 100 comprising:
• the electric heater 1 further comprises a main anti-return diode D8.
• the electric heater 1 further comprises a main return resistor R7.
• the electric heater 1 further comprises a secondary booster resistor R15.
• the electric heating device 1 further comprises a secondary anti-return diode D1 1.
• the electric heater 1 further comprises a base resistor R14.
• the first connection interface 112 is adapted to connect the electric heating device 1 with the first power supply network G12. It is an input that can receive a voltage supplied by the first G12 power supply network.
• the second connection interface I48 is adapted to connect the electric heating device 1 with the second power supply network G48. It is an input that can receive a voltage supplied by the second G48 power supply network.
• the first and second networks G12, G48 are connected to batteries
• the first power supply network G12 is adapted to supply a voltage U1 (called first voltage) lower than a voltage U2 (called second voltage) supplied by the second power supply network G48.
• the first power supply network G12 is adapted to provide a voltage U1 substantially equal to
• the second power supply network G48 is adapted to provide a voltage U2 substantially equal to 48V (volts). It is a high power network. Note that a battery, connected to the second network G48, which usually provides a voltage of 48V can provide a voltage that can go up to 58V.
• a voltage, for example 12V, provided by a battery is generally very unstable.
• the voltage U1 provided by the network G12 is filtered. This limits the voltage U1 which supplies the electric heater 1, in particular the secondary switch Q6 and the second protection switch Q4 described below.
• the filtered voltage U1 is thus represented in a triangle and inside the frame of the air blower 1. The filtering of a voltage being known to those skilled in the art, it is not described here.
• first connection interface 112 and the second connection interface I48 are connected to the same GND mass, also called GND common ground.
• ground cable CX to said common ground GND. Thanks to this common GND mass, it prevents overheating of the electric heater 1. Such overheating can indeed occur if two different masses are used, the two masses being dimensioned differently.
• a ground cable (called a signal ground cable) connected to the first connection interface 112 and a ground cable (called a power ground cable) connected to the second interface. connection I48.
• the power ground cable is disconnected when hot, in this case, there is indeed a risk that the signal ground cable burns because the two masses are dimensioned differently.
• the third ILW connection interface is adapted to connect the electric heater 1 with a communication bus BLW. It's an entrance.
• connection interfaces 112, I48, ILW thus comprise electrical connections adapted to make the connections respectively with the first power supply network G12, the second power supply network G48 and the communication bus BLW.
• the communication bus BLW is a LIN communication bus ("Local Internet connection Network").
• the electric heater 1 is part of a communication network NLW said LIN.
• a LIN communication bus is a bidirectional communication bus.
• a LIN communication network makes it possible to use only one wire for the communication of the signals.
• the communication bus BLW is a PWM communication bus ("Puise Modulation Width").
• the electric heater 1 is part of a communication network NLW said PWM.
• a PWM communication bus is a unidirectional bus.
• the electric heater 1 comprises two unidirectional PWM communication buses, one being used for receiving signals, and the other being used for sending signals.
• the communication bus BLW makes it possible to convey DAT signals from the electric heating device 1 to an external electronic device 2 (described below) and / or from the external electronic device 2 to the electric heating device 1.
• an LLW communication line internal to the electric heater 1 (illustrated in FIG. 1 for example) between the functional module 1 1 and the third interface of FIG. ILW connection over which said signals of the functional module 1 1.
• this communication line is an electronic track.
• the electric heater 1 further comprises a ground interface IGND.
• the IGND mass interface is an output.
• the ground cable CX connects the ground interface IGND to the chassis of the motor vehicle which forms a ground plane.
• the first protection module 10, the functional module 1 1, the main anti-return diode D8 and the main switch Q2 are part of the same printed circuit board, called the PCBA card (in English "Printed Circuit Board Assembly").
• This PCBA printed circuit board is thus connected to the ground plane formed by the chassis of the motor vehicle.
• the first connection interface 112 and the third ILW connection interface are part of the same connector BN12. This makes it possible not to multiply the connectors.
• the second connection interface I48 and the ground interface IGND form part of the same BN48 connector. This makes it possible not to multiply the connectors.
• the main switch Q2 is adapted to pass DAT signals on the communication bus BLW.
• the main switch Q2 is a MOSFET transistor. In a non-limiting embodiment variant, it is an N-channel transistor.
• the gate G of the transistor receives the first voltage U1, namely the voltage of 12V in the nonlimiting example taken, the source S is connected to the communication bus BLW via the third connection interface ILW, and the drain D is connected to the DLW control module.
• the main switch Q2 has a threshold voltage Vgsth.
• the main switch Q2 is closed when its voltage Vgs is equal to the voltage U1 provided by the first network G12, namely here 12V.
• the main switch Q2 comprises a breakdown voltage greater than 48Volts. In a non-limiting embodiment variant, the breakdown voltage is substantially equal to 100Volts.
• the main switch Q2 thus supports the voltage U2, here 48V, which it receives (in particular between the source S and the drain D in the non-limiting embodiment of the MOSFETS) during a surge USS or when the common ground GND is lost.
• the main switch Q2 is open when the voltage Vgs is lower than the voltage Vgsth, that is when Vgs is substantially equal to 0V in a non-limiting example. As we will see below, the main switch Q2 opens:
• the first protection module 10 protects the first power supply network G12 and the communication bus BLW against a surge USS
• the second protection module 20 allows to protect the first power supply network G12 and the communication bus BLW against a common ground loss GND.
• the electric heater 1 further comprises a protective diode D3 associated with the main switch Q2 illustrated in Figure 2a or 2b.
• This protection diode D3 is adapted to protect the main switch Q2 against an increase in the voltage U1 of the first power supply network G12, in particular against a voltage that is too high between its gate G and its source S.
• a fault can occur in the case of a fault of the alternator or the starter of the motor vehicle.
• the protective diode D3 is a Zener diode.
• the Zener diode D3 comprises a threshold voltage VS3. If the voltage V G s of the main switch Q2 becomes greater than or equal to this voltage VS3, the Zener diode closes said voltage V G s so that it is equal to the threshold voltage VS3. Thus, in a non-limiting example, the threshold voltage VS3 is equal to 20V. The main switch Q2 is thus protected. o usj.bJ.e " at p-resettable R6
• the electric heating device In a non-limiting embodiment, the electric heating device
• I further comprises a self-resetting fuse R6 illustrated in Figure 2a or 2b.
• This self-resetting fuse R6 is arranged in series with the main switch Q2, in particular between said main switch Q2 and the communication bus BLW.
• An overcurrent is a current that is too strong and that said BLW communication bus can not support.
• the main switch Q2 behaves like a resistor.
• the drain D 48V
• This current called sur-courant, is dangerous because the BLW communication bus does not support this level of overcurrent. This may damage said BLW communication bus or cut communications between the external electronic module 2 (described below) and the functional module 1 1 of the electric heater 1.
• the electric heater 1 further comprises a tertiary anti-return diode D6 (shown in Figure 2a or 2b) adapted to ensure that the main switch Q2 remains open.
• the tertiary anti-return diode D6 is arranged in series with the main return resistor R7. Its anode A is connected to the gate G of the main switch Q2 and its cathode K is connected to the source S of the main switch Q2 via the main return resistor R7.
• V s OV or 1 2V respectively if the DAT signals are transmitted or not.
• V s 1 2V
• this voltage of 12V can be found on the gate voltage V G , namely at node N4 illustrated in Figure 2a or 2b.
• the tertiary anti-return diode D6 is blocked when the potential difference V A K ⁇ VS6, with VS6 the threshold voltage of the tertiary anti-return diode D6.
• VS6 0.6V.
• the main switch Q2 opens when the secondary switch Q6 opens.
• the functional module 1 1 is connected to the first connection interface 112 and to the second connection interface I48 via the BN12 connector respectively and via the BN48 connector previously seen. It can thus be powered by the two different voltages U1 and U2 provided respectively by the two networks G12 and G48.
• the functional module 1 1 is also connected to the GND common ground via the BN48 connector.
• An electrical node N1 connects the functional module 1 1 to the first connection interface 112 via an electrical connection wire and to the third connection interface ILW via the secondary switch Q6 and the main switch Q2 described more far.
• the functional module 1 1 comprises a DLW control module described below (called “electronic driver”).
• An electrical node N2 called the second node, connects the functional module 1 1, in particular its control module DLW, and the main switch Q2 via the communication line LLW.
• An electrical node N3 connecteds the functional module 1 1 and the first protection module 10 at the common ground GND.
• the third node N3 is thus connected to the common ground GND via said functional module 1 1.
• an electrical node is also called a node.
• a potential difference of 48V-0V or 48V-12V (between the second node N2 and the third connection interface ILW) appears. leads to the appearance of a current i2 (shown in FIG. 3) flowing from the DLW control module to the communication bus BLW (via the third connection interface ILW) which risks damaging it, as well as the third connection interface ILW.
• the first protection module 10 (in particular the protection diode D1) described below and the main switch Q2 prevent such a current i2 from circulating and thus protects the communication bus BLW and the third connection interface ILW. These are not damaged.
• a potential difference of 48V-12V appears (between the third node N3 and the first connection interface 112) which causes the appearance of the current i3 (shown in Figure 3) flowing from the functional module 1 1 to the first connection interface 112 which may damage the first connection interface 112.
• the electric heating device 1 is an additional electric heating device.
• the functional module 1 1 comprises at least one resistive heating element 1 10 (illustrated in FIG. 1 and 3) and at least one associated control element 1 1 1 (shown in FIG. 1 and 3) for controlling the current in said at least one resistive heating element 1 10.
• Said resistive heating element 1 10 is connected to the second connection interface I48 and said associated control element 11 1 is connected to the first connection interface 11.
• the control element 11 1 is powered by the low power voltage U1 of 12V and the resistive heating element 1 10 is powered by the high power U2 voltage of 48V.
• the resistive heating element 1 10 is a heating resistor.
• the resistive heating element 1 10 is a resistive track.
• the heat produced by the resistive heating element 1 10 is transmitted via a fluid circulation duct (not shown) to said fluid which can thus be heated.
• a control element 1 1 1 comprises an electronic component such as a switch, which is in a non-limiting example, a MOSFET. It controls the current that feeds a resistive heating element 1 10.
• the current control in resistive heating elements is known to those skilled in the art, it is not described here.
• the electric heater 1 comprises a plurality of control elements.
• a control element 1 1 1 cooperates with a DLW control module of the functional module 1 1 which sends DAT signals to it.
• a DLW control module can control one or more control elements 1 1 1. The DLW control module is described below.
• the DLW control module comprises a switch Q8 in series with a pulling resistor R8. It is connected to the main switch Q2 of the electric heater 1.
• the DLW control module is described below with reference to FIGS. 5 and 6 in its operating mode when:
• the operating mode is described with a bidirectional BLW communication bus.
• the DLW control module is adapted to be supplied with voltage by the first power supply network G12. It is thus connected to the first power supply network G12 and GND common ground via the functional module 1 1. It is connected to the first network G12 via its pulling resistor R8 and GND common ground via its switch Q8.
• the DLW control module is adapted to receive and / or transmit DAT signals via the BLW communication bus. It transmits the received signals DAT to the control element 1 1 1 of the functional module 1 1, said control element 11 1 interpreting these signals DAT so as to drive the resistive heating elements 1 10.
• said electric heater 1 is adapted to operate in slave mode, it forms a slave module.
• the DLW control module is adapted to receive and transmit DAT signals on the communication bus BLW to and from an external electronic device 2 called the master module.
• the DAT signals are low logic signals.
• the low logic DAT signals are 0V signals. Note that in the case of the LIN protocol, the low logic signals are so-called dominant signals.
• the external electronic device 2 operates in master mode and comprises a switch Q9 and a pulling resistor R9.
• the master module 2 is powered by a low power voltage.
• the master module 2 is connected to the second power supply network G12 via its pulling resistor R9 and to the GND common ground via switch Q9.
• switches Q8 and Q9 are open. This corresponds to their initial state.
• the LIN protocol and the master-slave operation prevent them from closing at the same time. Note that for the PWM protocol which is unidirectional, it is not possible to have such collisions.
• a slave module 1 and the master module 2 form a communication network NLW.
• the communication network NLW can comprise a plurality of slave modules 1.
• the switches Q8 and Q9 are NPN switches.
• the master module 2 is the engine control ECU of the motor vehicle or an electronic device connected to the dashboard of the motor vehicle.
• the DAT signals are in a non-limiting example:
• this information indicates short-circuits, overvoltages, under-voltages, over-temperatures, faulty equipment, electrical consumption of the electric heater 1 etc.
• the master module 2 is powered by a voltage of 12V in the nonlimiting example taken as illustrated in FIGS. 5 and 6.
• FIG. 5 illustrates the sending of DAT signals from the master module 2 to the electric heating device 1 and
• FIG. 6 illustrates the sending of DAT signals of the electric heating device 1 to the master module 2.
• the switch Q9 switches so that signals 0V (corresponding to a logic signal 0) or 12V (corresponding to a logic signal 1) are sent on the communication bus BLW to the slave module 1.
• the switch Q9 closes, a logic signal 0 is sent, when the switch Q9 opens, a logic signal 1 is sent.
• Switch Q8 always remains open.
• the switch Q8 switches so that signals 0V (corresponding to a logic signal 0) or 12V (corresponding to a logic signal 1) are sent on the communication bus BLW to the master module 2.
• signals 0V corresponding to a logic signal 0
• 12V corresponding to a logic signal 1
• Switch Q9 remains open to him.
• the master module 2 when the master module 2 sends DAT signals to the electric heating device 1, it imposes a zero on the communication bus BLW (in the case where the DAT signals are of low logic) , the latter then being at GND ground potential. For this purpose, it closes its switch Q9. On the source S, there is therefore 0V and on the gate 12V (since the main switch Q2 receives on its gate G 12V of the first connection interface 112). The voltage Vgs of the main switch Q2 is equal to 12V (and therefore greater than a threshold voltage Vgsth) which causes that said main switch Q2 is closed. The DAT signals therefore arrive at the input of the DLW control module.
• the slave module here the electric heating device 1
• the master module 2 when the slave module, here the electric heating device 1, sends DAT signals to the master module 2, it imposes a zero (in the case where the DAT signals are of low logic) on the drain D of the main switch Q2.
• the slave module 1 closes its switch Q8.
• the switch Q8 is closed, the drain D is at ground potential GND, ie at 0V.
• the communication network NLW comprises a master module 2 and may comprise a plurality of slave modules 1, at least one slave module of which is powered by the first power supply network G12 and the second power supply network G48.
• the other slave modules 1 can be powered in the same way or only by the first G12 power supply network.
• the communication bus BLW makes it possible to route DAT signals from the master module 2 to all the slave modules 1.
• a DC short circuit occurs which generates an overvoltage USS on the electric heater 1 described above which is a slave module, it disconnects from the communication network NLW thanks to the first protection module 10, but the module master 2 and the other slave modules 1 continue to operate without being disturbed by the faulty slave module (the one that has been overvoltage).
• the NLW communication network is thus protected from a USS overvoltage on one of its slave modules 1.
• the first protection module 1 0 prevents:
• the main switch Q2 comprises a freewheel diode D2 (called “body diode”).
• the freewheeling diode D2 is adapted to ensure the closing of the main switch Q2.
• the freewheeling diode D2 is arranged between the drain D and the source S of the main switch Q2.
• a freewheeling diode is conducting when the voltage V A K equal to the potential difference between V at its anode A and V k its cathode K is greater than a threshold voltage VS2 (given by the manufacturer).
• VS2 0.6V.
• V k when the drain D is at 0V, the voltage V k is at 0V. Furthermore, V A is at 1 2V since before the switch Q8 closes, the source of the main switch Q2 was at 1 2V (thanks to the pull resistance R9 seen previously). Thus, there is V A K which is equal to 12V, ie greater than 0.6V.
• the freewheeling diode D2 thus makes it possible to close the main switch Q2 correctly.
• the electric heating device 1 comprises a main anti-return diode D8.
• the main anti-return diode D8 is adapted to prevent a current from flowing to the first power supply network G1 2 when the main switch Q2 is open. It provides protection for the secondary switch Q6 during a DC short circuit.
• the main anti-return diode D8 is disposed between the functional module 1 1 and the first connection interface 11 2, and in particular between the first electrical node N 1 and the first connection interface 11 2. More particularly, its cathode K is connected to the functional module 1 1 and its anode A is connected to the first connection interface 11 2.
• the first node N 1 rises to the potential of 48V.
• first node N 1 is at the potential of 48V (all the functional module 1 1 being mounted up to the potential of 48V) while the first connection interface 11 2 is at the potential of 1 2V since connected to the first network G 1 2 of 1 2V.
• the main anti-return diode D8 is adapted to prevent such a current from circulating from the second power supply network G48 via the first node N 1 to the first power supply network G 1 2 via the first connection interface 11. 2.
• the main anti-return diode D8 prevents the current it from passing when it is in a blocked state.
• the main anti-return diode D8 is in a blocked state when the voltage V A K which is equal to the potential difference V A at its anode A and V K at its cathode K is lower than its threshold voltage VS8 (given by the maker).
• VS8 0.6V.
• V A 1 2V (since connected to 11 2)
• V K 48V (the first node N 1 being at the potential of 48V).
• V A K negative and therefore V AK ⁇ VS8 Thus, the first connection interface 112 is protected against any short circuit DC from the second network G48 and therefore against any overvoltage USS.
• the main anti-return diode D8 also makes it possible to protect the battery connected to the first network G1 2 against a rise in potential.
• the potential 48V may end up on the battery 1 2V which would damage not only said battery, but also the other electronic elements of the motor vehicle which are powered by said battery.
• the first protection module 10 is illustrated in detail in FIG. 2a.
• the first protection module 10 is adapted to isolate the first power supply network G1 2 and the communication bus BLW from the second power supply network G48 when an overvoltage USS between the functional module 1 1 and the first connection interface 112 and the third connection interface ILW.
• Such overvoltage USS is found on the first node N1, on the second node N2 and on the third node N3.
• the first protection module 10 comprises:
• an overvoltage detection module 100 comprising:
• a first protective switch Q1 adapted to close when the protection diode D1 becomes conducting
• a secondary switch Q6 adapted to open when there is such a surge USS so as to open the main power switch Q2;
• a second protective switch Q4 adapted to open when the first protective switch Q1 closes so as to open the secondary switch Q6.
• the different elements of the protection module 10 are described in detail below.
• the overvoltage detection module 100 is illustrated in detail in FIG. 2a.
• the protection diode D1 is arranged between the main switch Q2 and the second protective switch Q4. Its cathode K is connected to the drain D of the main switch Q2 and its anode A is connected to the base B of the second protection switch Q4 and to the GND common ground via a resistor R1 described below.
• the protection diode D1 comprises a threshold voltage VS1 greater than the voltage U1 supplied by the first power supply network G12, namely greater than 12 volts.
• the threshold voltage VS1 22V.
• the protection diode D1 is on when V A K ⁇ - VS1.
• the protective diode D1 is a Zener diode.
• the Zener diode D1 closes said voltage U1 0 so that it is equal to the threshold voltage VS1.
• the first protection switch Q1 is connected to the second protection switch Q4.
• the first protective switch Q1 is a bipolar transistor.
• the bipolar transistor Q1 is of the NPN type. Its collector C is connected to the base B of the second protection switch Q4.
• the node N7 illustrated in FIG. 2a forms the connection between the base B of the second protective switch Q4, the collector C of the first protective switch Q1 and a resistor R3 illustrated in FIG. 2a.
• the resistor R3 makes it possible to apply to the collector C of the first protective switch Q1 the first voltage U1, namely 12V.
• the first protection switch Q1 is open.
• the base B of the second protection switch Q4 is connected to 12V via a resistor R3.
• the resistor R3 in fact reduces the potential 1 2V on the base B of the second protection switch Q4.
• the resistor R3 makes it possible to drive the second protective switch Q4 and thus makes it possible to keep the second protective switch Q4 closed.
• the first protective switch Q1 comprises an internal resistance between its base B and its emitter E and a basic internal resistance B. These internal resistances make it possible to close the first protective switch Q1 when the protection diode D1 becomes bandwidth. It will be noted that the fact of using internal return resistors makes it possible to save space.
• the first protective switch Q1 closes when there is a DC short circuit and therefore a USS overvoltage as seen above.
• the first protection module 10 further comprises a resistor R1.
• the resistor R1 is connected to the common ground GND and to the protective diode D1 seen previously.
• the resistor R1 is adapted to operate the protection diode D1 so as to drive the first protective switch Q1 through its internal resistors.
• the voltage across the resistor R1 is the clipped voltage U1 seen previously.
• the current (not shown) passing through the resistor R1 and thus by the protective diode D1 is of the milliampere order.
• the second protection switch Q4 is adapted to open:
• the second protection switch Q4 is connected to the first power supply network G12 via the resistor R3.
• the resistor R3 is thus adapted to drive the second switch of Q4 protection.
• the resistor R3 is adapted to limit a current that could flow between the first power supply network G12 and the base B of the second protective switch Q4 in the case where the first protective switch Q1 would close.
• there would be a short circuit which would generate a current in the second protective switch Q4 of a few thousand amperes.
• Said second protective switch Q4 could not withstand such a strong current.
• Resistor R3 thus makes it possible to protect said second protective switch Q4 by limiting the current flowing in its base B, referenced Ib4.
• the resistor R3 is thus sized to have a current Ib4 base B adapted to the second protective switch Q4. Similarly, the resistor R3 is adapted to limit a current that could flow between the first power supply network G12 and the base B of the first protection switch Q1. Resistor R3 is a so-called "pull-up" resistor.
• the second protection switch Q4 is arranged between the first protective switch Q1 and the secondary switch Q6.
• the second protective switch Q4 is a bipolar transistor.
• the bipolar transistor Q4 is of the NPN type. Its collector C is connected to the base resistor R14 (described below), its emitter E is connected to the GND common ground (via the secondary non-return diode D1 1 described below), its base B is connected to the collector C the first protection switch Q1.
• the third node N3 connects in particular the functional module 1 1 and the second protective switch Q4.
• the second protection switch Q4 is closed by default. When closed, the second protection switch Q4 is controlled by the resistor R3.
• the second protective switch Q4 further comprises an internal resistor (illustrated but not referenced) located between its base B and its emitter E and an internal resistor resistor located between the resistor R3 and its base B. These internal resistor resistors with the resistor R3 make it possible to apply to the emitter E of the second protection switch Q4 the first voltage U1, namely 12V.
• the fact of using internal return resistors saves space.
• the second protective switch Q4 is closed when the first protective switch Q1 is opened as previously seen.
• the second protection switch Q4 opens when the first protective switch Q1 closes as previously seen.
• the opening of the second protection switch Q4 causes the base resistor R14 (described below) to be disconnected from the common ground GND.
• the base B of the secondary switch Q6 is no longer connected to the GND common ground, it becomes floating.
• the potential 12V is installed therefore. Indeed, thanks to the secondary resistor R15 (described later), the base B of the secondary switch Q6 rises to 12V.
• the second protective switch Q4 when the second protective switch Q4 opens, it causes the opening of the secondary switch Q6, and therefore the opening of Q2 (as described below) so that the first power supply network G12 and the BLW communication bus are disconnected from the second G48 power supply network. They will no longer be disturbed by a DC short circuit and therefore by a USS surge.
• GND common ground loss occurs, the emitter E of the second protective switch Q4 is floating. In this case, no current can pass in the emitter E.
• the opening of the second protective switch Q4 causes the opening of the secondary switch Q6, the latter causing the opening of the main switch Q2 as described below.
• the secondary switch Q6 is adapted to open:
• the secondary switch Q6 is closed by default.
• the secondary switch Q6 is a bipolar transistor.
• the bipolar transistor Q6 is of the PNP type. Its base B is connected to the collector C of the second protection switch Q4, its emitter E is connected to the first network G12, and its collector C is connected to the gate G of the main switch Q2.
• the second node N2 rises to the potential 48V and a potential difference, here of 48V-0V (DAT signals are emitted) thus appears on the second node N2 and on the module DLW driver, which generates the current i2 which It travels on the communication bus BLW via the main switch Q2 if the latter is closed and if DAT signals circulate on the communication bus BLW, said DAT signals being at OV as previously described.
• the DLW control module and the BLW communication bus do not support such a current i2 and may therefore be damaged.
• the secondary switch Q6 (which opened as previously seen following the detection of the overvoltage USS by the protective diode D1) opens the main switch Q2 and thus prevents such a current i2 to flow in the bus BLW communication (via the third ILW connection interface). The latter is thus protected as well as the third ILW connection interface.
• the main switch Q2 in particular its gate G (connected to the collector C of the secondary switch Q6) in the non-limiting example of the MOSFET, is no longer powered by the voltage U1, namely 12V, and therefore the potential of the gate G is equal to 0V.
• the tertiary anti-return diode D6 prevents the main return resistance R7 from allowing a voltage to pass from the source S to the gate G.
• the main switch Q2 opens.
• the second switch protection Q4 opens as seen previously, which causes the opening of the secondary switch Q6, it is in a blocked state.
• the secondary switch Q6 opens, this opens the main switch Q2.
• the main switch Q2 By opening the main switch Q2 during the loss of common ground GND, the second network G48 was disconnected from the communication bus BLW.
• the electric heater 1 further comprises a main return resistor R7.
• the return resistor R7 is adapted to guarantee the opening of the main switch Q2 when said main switch Q2 must open (during a USS overvoltage or when a common mass loss GND).
• the main return resistor R7 is connected to the cathode K of the tertiary anti-return diode D6 and to the source S of the MOSFET transistor Q2.
• the applied control level ie the value of the voltage applied
• the grid does not see the voltage 12V or 0V. It is in a floating state, and could force it to enter conduction, either completely (with risk of erratic operation of the electric heater 1), or partially (with risk of destruction of the main switch Q2).
• the potential of the gate G of the main switch Q2 is 12V, because the secondary switch Q6 is closed.
• the node N4 (and the node N5) illustrated in Figure 2a is at the potential of the voltage U1, namely 12V in the example.
• the main switch Q2 When the secondary switch Q6 opens (due to a USS overvoltage or GND common ground loss), the main switch Q2 opens.
• the node N4 corresponds to the grid voltage V G of the main switch Q2.
• Node N4 (as well as node N5) becomes floating.
• This potential difference generates a current (not shown) which will flow in the tertiary anti-return diode D6 and the main return resistor R7 and will go to the source S and the auto-resettable fuse R6.
• the node N4 (and the node N5) will thus descend to the potential 0V of the source S.
• the resistor R7 allows the node N4 and thus the gate G of the main switch Q2 to be 0V quickly . This will have the voltage Vgs at 0V which guarantees the opening of the main switch Q2.
• the main return resistor R7 is a so-called pull-up resistor.
• the electric heater 1 further comprises a secondary booster resistor R15.
• the secondary resistor R1 5 is adapted to ensure the opening of the secondary switch Q6 when said secondary switch Q6 must open (during a USS overvoltage or when a GND common mass loss).
• the secondary resistor R1 is connected to the base B and to the emitter E of the bipolar transistor Q6.
• the secondary resistor R1 5 can control the secondary switch Q6 opening when its base B is floating, namely when the second protective switch Q4 opens as described above.
• this secondary resistor R1 5 can initialize the voltage V B E of the secondary switch Q6 to 0V (it is therefore by default to 0V) which guarantees the opening of the secondary switch Q6 when there is no current Ib6 flowing in the base B of said secondary switch Q6.
• the secondary return resistor R15 is a so-called “pull-out” resistor. up ".
• the first protection module 10 further comprises a secondary anti-return diode D1 1.
• the secondary anti-return diode D1 1 is adapted to prevent a current i3 from circulating in the second protective switch Q4. It thus ensures the protection of the second protective switch Q4 during a DC short-circuit.
• the secondary non-return diode D1 1 is arranged between the functional module 1 1 and the second protective switch Q4.
• the third node N3 thus connects in particular the functional module 1 1 and the secondary anti-return diode D1 1.
• the secondary non-return diode D1 1 is connected to the common ground GND via the functional module 1 1.
• the anode A of the secondary non-return diode D1 1 is connected to the emitter E of the second protective switch Q4, and its cathode K is connected to the common ground GND.
• the second protection switch Q4 may break. Therefore the protection of the main switch Q2 is no longer assured. It is the same when the common mass GND is lost.
• the secondary non-return diode D1 1 is adapted to prevent such a current i3 from circulating in the second protective switch Q4. It thus protects said second protective switch Q4.
• the secondary anti-return diode D1 1 prevents the current i3 from passing when it is in a blocked state.
• the secondary non-return diode D1 1 is in a blocked state when the voltage V A K equal to the potential difference V A at its anode A and V K at its cathode K is less than its threshold voltage VS1 1 (given by the manufacturer).
• VS1 1 0.6V. We have such a difference when there is a USS overvoltage.
• V A K negative ⁇ VS1 1.
• V EB 0V. Note that it is the same when the common mass GND is lost.
• the secondary anti-return diode D1 1 is conducting when V AK > Vs. This is obtained when there is no short circuit. Indeed, in this case, there is V A at potential 1 2V and V k at the ground potential.
• the electric heater 1 further comprises a base resistor R14.
• the base resistor R14 is adapted to size the base current Ib6 which flows in the secondary switch Q6.
• the base resistor R14 is arranged between the secondary switch Q6 and the second protective switch Q4.
• the base resistor R14 is connected to the base B of the secondary switch Q6 and to the collector C of the second protective switch Q4.
• the basic resistance R14 makes it possible to drive the secondary switch Q6 on closing by virtue of the base current Ib6 which it supplies.
• the sizing of the base current Ib6 ensures the closure of the secondary switch Q6. In addition it avoids having a current Ib6 too important which could break the component Q6.
• the threshold value of Ib6 for the secondary switch Q6 to close is Ib6> lc / ⁇ , with the collector current and ⁇ current amplification of the switch given by the manufacturer of the switch.
• the electric heater 1 further comprises an additional protective diode D1 2.
• the additional protection diode D1 2 to protect the secondary switch Q6 against a voltage inversion U1.
• the additional protection diode D12 is arranged between the secondary switch Q6 and the first network G1 2.
• the second protection module 20 is illustrated in detail in FIG. 2b.
• the second protection module 20 is adapted to isolate the first electrical network G1 2 and the communication bus BLW from the second power supply network G48 during a loss of the common ground GND.
• the common ground GND is lost when the ground connecting cable CX which connects the first and second connection interfaces 112 and I48 to the common ground GND is cut as shown in FIG. 4.
• the second protection module 20 is part of the first protection module 10. In fact, it comprises:
• the second protection module 20 further comprises the main return resistor R7.
• the second protection module 20 protects these elements against said currents as follows.
• the second protection switch Q4 cascades the secondary switch Q6 and the main switch Q2 (as previously described) which allows the secondary switch Q6 to prevent such a current from circulating.
• a potential difference of 48V-0V (between the second node N2 and the communication bus BLW) appears which causes the appearance of a current i2 (shown in FIG. 4) flowing from the DLW control module to the communication bus BLW (via the third connection interface ILW) which risks damaging them.
• the second protection switch Q4 cascades the secondary switch Q6 and the main switch Q2 (as previously described) which allows the main switch Q2 to prevent such a current i2 from circulating (as previously described) in the BLW communication bus. The latter is thus protected as well as the third ILW connection interface.
• the DLW control module when the GND common ground is lost, the DLW control module is no longer referenced to ground. It rises to the potential of 48V (all the functional module 1 1 being mounted up to the potential of 48V). Without the second protection module 20, the DLW control module would see at its terminals a potential difference of 48V-0V which corresponds to the difference between the potential of 48V (applied to the functional module 1 1) and the potential of 0V of the DAT signals transmitted on the BLW communication bus. This potential difference causes the appearance of a current i2 (shown in Figure 4) flowing in said DLW control module which may damage it. Indeed, the DLW control module does not support such a significant difference in potential.
• the second protective switch Q4 cascades the secondary switch Q6 and the main switch Q2 (as previously described) which allows the main switch Q2 to prevent the current i2 from when the GND common ground is lost, there will be no potential difference across the DLW control module and therefore more current flowing i2.
• the DLW control module will only be at 48V potential. It will not be damaged.
• the DLW control module will be protected in case of GND common mass loss.
• the DLW control module is not protected by the first protection module 10 against a DC short-circuit, but it is protected by the second protection module 20.
• a potential difference of 48V-0V between this third node N3 and the communication bus BLW which causes the creation of a current i3 (illustrated in FIG. 4) between said third node N3 and said communication bus BLW.
• the third node N3 rises to the potential of 48V while the communication bus BLW is at the potential of 0V because of the DAT signals at 0V.
• the second protection switch Q4 opens as previously seen. It thus prevents such a current i3 from circulating and thus protects the first connection interface 112 and the communication bus BLW as well as the third connection interface ILW.
• a USS overvoltage detection is converted into a detection of the loss of the common ground GND.
• Common components are used to protect the first connection interface 112 and the third ILW connection interface (and thus the BLW communication bus) against the loss of the GND common ground and against said USS overvoltage.
• the second protection switch Q4 opens which has the consequence that the base resistor R14 disconnects from the GND common ground as seen above, which corresponds to a loss of the common mass GND.
• the continuation of the operation of the protection against a USS overvoltage or against a GND loss of mass is the same for the first protection module 10 and for the second protection module 20 as previously seen.
• the secondary switch Q6 may be a MOSFET transistor or an IGBT transistor. In these cases, the basic resistance R14 is not necessary.
• the first connection interface 112 and the second connection interface I48 are connected to two different masses. In this case, it does not have a second protection module 20.
• bidirectional or unidirectional protocols other than the LIN or PWM protocol can be used.
• the invention can also be applied to an air blower 1 for a motor vehicle.
• the air blower 1 for a motor vehicle is adapted to be supplied with voltage by a first power supply network G12 and a second power supply network G48.
• the air blower 1 comprises:
• a functional module 1 1 connected to the first connection interface 112 and to the second connection interface I48; a main switch Q2 connected to the functional module 1 1 adapted to pass DAT signals on the communication bus BLW;
• a first protection module 10 adapted to isolate the first power supply network G12 and the communication bus BLW from the second power supply network G48 when there is an overvoltage USS between the functional module 1 1 and the first interface of connection 112 and the third ILW connection interface.
• the functional module 1 1 comprises at least one driving load 1 10 and at least one associated driving element 1 1 1 for driving the current in said at least one driving load 1 10.
• Said driving load 1 10 is connected to the second connection interface I48 and the control element 1 1 1 is connected to the first connection interface 112.
• the control element 1 1 1 is powered by the low power voltage U1 12V and said driving load 1 10 is powered by the high power U2 voltage of 48V.
• Said driving load 1 10 makes it possible to turn the motor of the air blower 1.
• an air blower 1 comprises:
• centrifugal type wheel mounted on an axis of the electric motor
• an engine support comprising a housing in which the electric motor can be housed.
• All of these elements are configured to be mounted in an air conditioning, ventilation and / or heating device via said motor support.
• a control element 1 1 1 is mounted on the motor support of the air blower 1.
• a control element 1 1 1 is mounted at a distance from the air blower 1 on or in the air conditioning, ventilation and / or heating device.
• air blowers are known to those skilled in the art, they are not described in detail here.
• an air blower 1 is used in an air conditioning, ventilation and / or heating device for a motor vehicle (called HVAC "Heating Ventilation and Air Conditioning") or for cooling the engine. of the motor vehicle.
• the main anti-return diode D8 and the main switch Q2 allows, thanks to the first protection module 10, the main anti-return diode D8, and the main switch Q2, during a USS overvoltage (in particular in the case of a short circuit CC) in the second power supply network electrical G48 and therefore during a USS overvoltage, to isolate the BLW communication bus and the first connection interface 112 of the second connection interface 148, and therefore the second G48 power supply network. They are not damaged;

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• 2016
  • 2016-09-23 FR FR1658988A patent/FR3056875A1/fr active Pending
• 2017
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