SWITCH PROTECTION SYSTEM

Abstract

The present invention relates to a switch protection system (100) for a vehicle. The system (100) includes a microcontroller unit (102) and a switch (104) operable to connect a power source (106) to the microcontroller unit (102). The system also includes a leakage current detection module (108) connected in series with the switch (104) to detect leakage current in the switch (104). The system (100) further includes a wetting current module (112) to supply wetting current to dry contacts of the switch (104). Thus, the present invention seeks to overcome false detection of the switch (104) by detecting leakage current and passing wetting current through the switch contacts to destroy insulating oxide that may have deposited on the switch.

Description

SWITCH PROTECTION SYSTEM Invention Engineering Field This invention relates generally to vehicles, and more specifically, relating to the protection system switch for vehicle. Background of the Invention Hybrid electric vehicles (HEVs) and electric vehicles (EV) is currently experiencing increasing demand due to the decreasing supply of fossil fuels and the consequences carbon dioxide emissions from exhaust from engine vehicles conventional internal. Modern HEVs and EVs can provides the option to select the driving mode. Mode driving is meant to offer an experience different driving modes, for example, comfort mode for “smooth and quiet ride” compared to Sport mode for fast and full driving adventure'. To provide a driving experience that different in that way, the driving mode changes vehicle driving characteristics by changing the elements, such as steering weight, engine, gearbox, and suspension settings. Short Description of Image The following detailed explanation refers to the pictures, that is: Figure 1 illustrates the block diagram of the protection system. switches for vehicles, according to the implementation example this topic: Figure 2 illustrates a circuit level diagram. from the leakage current detection circuit, according to the example implementation of this topic, and Figure 3 illustrates a circuit level diagram. from the wetting current circuit, according to examples of implementation of this topic: In all images, the reference numbers are identical. define elements that are similar, but not necessarily identical. The images do not always follow the scale, and the sizes some parts may be exaggerated to illustrate more clearly the example that shown. In addition, the image provides examples and / or implementation that is consistent with the explanation, however, explanations are not limited to examples and / or implementations provided in the image. Complete Description of the Invention This invention relates generally to vehicles, and more specifically, relating to the protection system switch for vehicle. Hybrid electric vehicles (HEVs) and electric vehicles (EV) generally includes switches that are operated automatically. mechanically for purposes such as changing driving modes, for example. The mechanically operated switch may include switch contacts that perform the function diversion by mechanically shifting the contact points. Switch contacts are the conductive parts of the switch. This and can be used to form and break connections. electricity. The control unit in such vehicles it can be assigned to read the state of this switch and respond appropriately to changing driving modes. Switch contacts are typically made of metal, which its conductive properties can be disrupted due to exposure to surrounding atmosphere. Under humid conditions, when in contact metal switch is left open in the atmosphere, it can reacts with moisture and air and forms oxides insulation on the outer layer. This can affect operation of the switch. For example, due to oxidation on the switch contacts, the switch remains electrically “open” even though the switch is closed due to the insulating oxide formed on the switch contacts can cause an increase in obstacles. This can lead to false detection by the unit controller. There may be other possibilities for false detection by controller. For example, if water droplets enter between the switch contacts, the drops can form conductive path between the switch terminals and allows current to flow through the switch. As a result of this, a switch may appear to be electrically “closed” even though it is open. False contacts can allow a small amount of current through the switch, known as leakage current. The current leaks can, in some cases, cause the controller unit to fail. detects the switch as closed even though its terminals are closed mechanically open. Example of a switch protection system for vehicles explained here which avoids false detection activation of the switch so that the controller unit is enabled to read the switch state correctly and respond appropriately to perform the corresponding function, such as changing the vehicle's driving mode. In one embodiment, the switch protection system includes microcontroller unit and switches that can operate to connect the power source to the microcontroller unit. The microcontroller aims to read the state of the switch and respond appropriately. The switch protection system is more further includes a related leakage current detection module in series with the switch. Leakage current detection module detect leakage current on the switch. The leakage current detection module includes a voltage divider unit. which receives the first voltage input from the switch. Unit The voltage divider reduces the first voltage input to reaches the set voltage. Current detection module further leaks include comparison units that have first terminal and second terminal. First terminal is to receive the second voltage input from the filter the second low pass, and the second terminal is for receive reference voltage input from a reference voltage source which is connected to the second terminal of the comparison unit. Unit The comparator produces an output signal based on the input second voltage and reference voltage input. Thus, the presence of leakage current in the switch can detected by comparing the second voltage input and reference voltage input. For example, if the second voltage input greater than the reference voltage input, then the switch detected as “ON” by the microcontroller unit, so that it indicates that there is no leakage current passing through switch. Alternatively, input a reference voltage that higher when compared to the second voltage input indicates the presence of leakage current through the switch. causes the microcontroller unit to detect the status switch as “OFF”. The switch protection system also includes a current module a wetting agent that supplies wetting current to the switch contacts dry. The wetting current modules are connected in series with a switch through the first one-way diode. In for example, the microcontroller unit identifies the switch contacts fake based on the comparison of the values ​​of the voltage input second and input reference voltage. So, by detecting the leakage current that passes through switch, false switch contacts can be detected by the unit microcontroller. Also, by passing a wetting current through the switch, the insulating oxide on the switch contacts can be destroyed and electrical contact during operation the switch can be maintained, thus addressing the problem false detection of the switch by the controller unit due to insulating oxide deposition on the switch. The above switch protection system is further explained by referring to Figures 1 to 3. It is necessary Please note that the explanations and pictures are for information only. illustrate the main principles of this discussion together with the examples described here and should not be interpreted as a limitation on the subject matter 1ni. Thus, note that various arrangements can be made. designed which, although not explicitly explained or shown here, explaining the basic principles this discussion. In addition, all statements here that mention the principles, aspects and examples of the topic This, as well as specific examples, is intended to cover things that are equivalent. Figure 1 illustrates a schematic diagram that illustrates the structure of the switch protection system (100) for vehicles, in accordance with the implementation of the subject matter This. The switch protection system (100) can be implemented in different segments of HEV and EV, such as cars, trucks, caravans, sport utility vehicles, vehicles all terrain, snowmobiles, two-wheelers, buses, semi-trucks, and its kind. The switch protection system (100) includes a unit microcontroller (MCU) (102) and switch (104) which can operated to connect the power source (106) to the MCU (102). MCU (102) can be connected to components in vehicles using the area network bus controller (CAN). For example, the MCU (102) can be connected to engines, air conditioners, GPS modules, and the like vehicles via CAN bus. In an exemplary embodiment, the resource (106) may be high capacity built-in battery (not shown) which provides power to the components in the vehicle. The battery may include one or more packs high capacity battery or one or more cells low capacity. It is understood that the resources (106) can be logically connected to the MCU (102) with using a power management system, so that implement functions such as changing modes steering, delivering power to the ignition system, and power consumption management using a system power management. The switch (104) can be mechanically operated to close an electrical circuit. For example, when mechanical deformation of the elastic element of the switch (104), the contacts of which mechanically connected to the elastic element can be stressed to other contacts, thus, the electrical circuit closed. The switch protection system (100) further includes leakage current detection module (108) connected in series with switch (104). The leakage current detection module (108) is to detect leakage current through the switch (104). As explained above, the leakage current detection module (108) can detect current leaks that may occur due to the presence of water droplets, mud, automotive fluids, or any other contaminants between the switch contacts on the switch (104). The switch protection system (100) of the present invention also includes the wetting current module (112). The wetting current module (112) supplies wetting current to the switch contacts (104) which dry. Thus, the wetting current module (112) responsible for removing all layers of oxidation which is formed in the contact area of ​​the switch (104) due to moisture. It should be understood that the wetting current module (112) can provide a constant supply of wetting current without must receive any input from the MCU (102), therefore that, false or leakage current detection may not be necessary for operation of the wetting current module (112). Structure and detailed working of leakage current detection module (108) and the wetting current module (112) will be elaborated next in connection with Figures 2 and 3 respectively. Furthermore, when the switch (104) is closed, the signal bouncing signals can appear in switch input signal. If the microcontroller unit (102) respond to such signals for critical applications such as change mode to power mode from mode economy mode and vice versa, changes that Unintentional events such as false detections can occur. Such unintentional changes in behavior vehicles can disturb vehicle users or even can cause accidents because the driver may not be be ready for sudden changes in behavior vehicle. To avoid such situations, the system switch protection (100) may include a filter circuit first (110). The first filter circuit (110) filters any noise from the signal before sending it to the MCU (102), thus ensuring that there are no rapid changes in terms of fashion- fashion, and so on, which leads to functioning smooth vehicle. Figure 2 illustrates a circuit level diagram. for the leakage current detection circuit (108), in accordance with implementation of this topic. As shown in Figure 2, the leakage current detection circuit (108) includes the voltage divider unit (202). Regardless of the status Turn ON or OFF the switch (104), immediately after the switch (104) receives the first voltage input, the detection circuit leakage current (108) starts to conduct. The first voltage signal This is made to come down to the voltage divider ratio that has been determined by means of a voltage divider unit (202) which includes a number of resistors (214, 216), as shown in Figure 2. Then, the reduced voltage fed to a second low pass filter (210) which formed by the filter resistor (218) and the capacitor (220). In the example, the ratio by which the first voltage signal is derived by the voltage divider unit (202) can be selected so that such that the resistance is less than 300 ohms at the switch (104) is considered as a closed switch. The divider ratio voltage can consider resistances greater than 300 ohms as obstruction caused by a layer of contamination that formed on the contact surface of the switch (104). An example scenario is described here for elaborates the working of the voltage divider unit (202). In the example, if the reference voltage input to the voltage source reference (212) is 2.5 volts (V) and the input voltage is given by the power source (106) is 12 V, the divider unit voltage (102) will divide the input voltage by 12 V to 3 V, which is produced by means of 12“0.25, with the constant of 0.25 is the voltage divider ratio which has been determined to have a fixed value. Also, bearings of 0.5, which is produced through the equation in the form of 3v- 2.5V, can be given to detect real input from switch (104) with contamination on the switch contacts (104). However, if the switch (104) is not closed properly actual, due to contamination, resistance on the switch (102) more than 300 ohms, in such a situation, the output of the voltage divider unit (202) will be smaller than the reference voltage input, which is 2.5 V, which causes the second input voltage to be low compared to with a reference voltage input indicating that the switch is on (104) open or OFF. The on-state resistance of the switch (104) can be approximately 10 ohms and an off-state resistance of about 300 ohms, in the example. However, it is also to be understood that the obstacles switches can depend on their specifications, and with Thus, it can have different values. Therefore, the voltage divider ratio needs to be configured with considering the resistance of the given switch. The second low pass filter (210) produces an input second voltage based on the first voltage input with filter out any signals that eliminate reflections (debouncing signal) that may have been generated when switch (104) is in the ON position. The second voltage input received from the filter The second low pass (210) is entered into the first terminal (206) comparison unit (204) included with the circuit leakage current detection (108). Second terminal (208) of the unit comparator (204) is equipped with a reference voltage input from the reference voltage source (212). In the example, the terminal first (206) comparison unit (204) can be positive, and The second terminal (208) can be negative or vice versa. In another example, the reference voltage source (212) can be battery. Furthermore, the comparison unit (204) compares output from the second low pass filter (210), namely the second voltage input with voltage input reference generated from the reference voltage source (212). If the second voltage input is greater than the voltage input reference, then the switch (104) is detected as ON, if no, as DEAD by MCU (102). Therefore, input higher reference voltage when compared to second voltage input received at the first terminal (206) comparison unit (204) indicates that switch (104) not closed, and there is leakage current through the switch (104). As soon as the MCU (102) receives a signal that switch (104) is in the OFF state, accordingly, it may not respond to the signal from the switch (104), thus overcoming the problem of false detection of switches. Therefore, the leakage current detection circuit (108) designed in such a way that it is possible to detect whether the switch (104) is letting current flowing or current is flowing due to the presence of water droplets or mud or any other automotive fluids between the switch contacts (104). An example scenario is described here for elaborate the working of the leakage current detection circuit (108). To detect the presence of leakage current through switch (104), leakage current detection circuit (108) measures resistance on the switch (104) during its operation. The switch (104) may have a predetermined barrier that fixed value, for example 300 ohms. When receiving input voltage through switch (104), leakage current detection circuit (108) will check whether the resistance on the switch (104) is around 300 ohms or not. If the resistance on the switch (104) is less than 300 ohms, then the MCU (102), through its connection to the leakage current detection circuit (108), can detects switch (104) as closed or ON, and therefore, it can perform its intended function. Meanwhile, if the resistance on switch (104) is more than 300 ohm, then the switch (104) can be considered as open or OFF by MCU (102), thus confirming the presence of drops alr or mud or any other automotive fluid between switch contacts (104). Figure 3 illustrates a circuit level diagram. for the wetting current circuit (112), in accordance with implementation of this topic. In the example, the wetting current can be considered as the minimum current required to flows through the switch (104) when operating, to breaking down any oxidation film that may have settled on the switch contacts. In the switch (104) ON state, the wetting current circuit (112) is arranged to allow minimum current flow through the switch (104) sufficient, for example, to clean up oxidation that perhaps from the switch contacts in such a way that the problem of false detection of the switch can be resolved as well total power consumption can be reduced. As shown in Figure 3, the circuit wetting current (112) is connected in series with the switch (104) through the first one-way diode (302). Current circuit The damper (112) includes an inductor unit (304) and a single diode second direction (306). The second one-way diode (306) is connected in parallel with the inductor unit (304). Current circuit The wetting unit (112) also includes a transistor unit (308) which connected in series with the inductor unit (304). The unit transistor (308) is configured to receive input control or pulse of wetting current from microcontroller unit (102). The control input triggers the transistor unit (308) to initiate a regular interval wetting current flowing through switch (104). In operation, when the control input high, current will flow through the first one-way diode (302), inductor unit (304), and transistor unit (308), individually. In the case of low control input, the current will circulate through the loop formed by inductor unit (304) and second unidirectional diode (306) without causing any high voltage spikes. In an implementation example, the inventors of this invention, for the calculation of the wetting current circuit design (112), it has been assume that the voltage input provided by power source (106) to switch (104) is 14 volts and the unit inductor (304) has an inductance of 22 microhenry, but it will be obvious to someone skilled in the field This invention is that design calculations can be built on other values ​​too. 1- (5)-oe, with I — permissible wetting current in the switch, Dt - time for which the current is allowed, Dt - 1 microsecond. PA eijaaus — h——ls lu 22uH IT — 0.636 A. Therefore, to pass the current of above value, transistor unit (308) is turned on for 1 microsecond. This can be repeated at regular intervals of 10 milliseconds. In other words, the inventors have determined that, for this implementation through experiments, the current a wetting agent that has the same value as I will necessary to clean any possible oxidation from switch contacts, thus maintaining health switch (104). In the example, the wetting current circuit (112) can implemented for a number of n switches. In the case of as such, the anode side of the first unidirectional diode (302) can be arranged in series with each switch, and then, the cathode section of each diode is one way (302) can be fired and connected to the circuit wetting current (112). The configuration has the advantage is that if no switch is ON, then The wetting current circuit (112) does not need to operate. In another example, the wetting current module (112) may be common to number of n switches. As an advantage of this, no it will be necessary to detect false switch contacts, because wetting current module (112), which is independent of any input, will continue to send wetting current in intervals- fixed intervals to remove any oxidation layers of all switches that may be part of a circuit. So, it is inversely proportional to the wetting current circuit. conventional resistive, wetting current circuit (112) type This diversion consumes very minimal current because current only needs to flow for a specified duration of time short. Therefore, the power loss in the current circuit the wetting agent (112) of the present invention will be very little. Also, because a single wetting current switching circuit can used for a number of n switches, the number of components becomes low and reliability will be high. Although examples for this disclosure have been described in a language specific to the method and / or feature structural, it should be understood that the attached claims do not always limited to specific methods or features that explained. Instead, specific methods and features are disclosed and is described as an example of this disclosure.

Claims

l. Switch protection system (100) for vehicles, system switch protection (100) which includes: microcontroller unit (102): switch (104) which can be operated to connect resource (106) to the microcontroller unit (102): leakage current detection module (108) which is connected in a series with switch (104) to detect leakage current on switch (104), leakage current detection module (108) which includes: voltage divider unit (202) that receives input the first voltage from the switch (104), in that case, voltage divider unit (202) is to reduce input the first voltage until it reaches the divider ratio the set voltage, and comparison unit (204) having a first terminal (206) and the second terminal (208), in that case, The first terminal (206) is for receiving input. second voltage of the second low pass filter (210), and the second terminal (208) is for receiving input reference voltage from the reference voltage source (212) which connected to the second terminal (208) of the comparison unit (204), in that case, a second voltage input is received when feeding the first voltage input to the filter second low pass (210), and in that case, the comparison unit (204) generate output signals based on input voltage second and reference voltage input: and wetting current module (112) to supply wetting current to the dry contacts of the switch (104), in case said, the wetting current module (112) is connected in series with switch (104), in that case, the microcontroller unit (102) is to identify fake switch contacts based on comparison of the values ​​of the second voltage input and the input reference voltage.

2. The switch protection system (100) as claimed in claim 1, in said switch protection system, the unit microcontroller (102) provides control input to the module wetting current (112) if switch (104) is closed.

3. The switch protection system (100) as claimed in claim 2, in said switch protection system, the module wetting current (112) includes: inductor unit (304): the second unidirectional diode (306) which is connected in a parallel with unit 1 inductor (3041): transistor units (308) connected in series with inductor unit (304), transistor unit (308) for receives control input from the microcontroller unit (102), in that case, the control input is to trigger transistor unit (308) to initiate the flow of wetting current regular intervals via switch (104). 4, The switch protection system (100) as claimed in claim 1, in said switch protection system, the filter the second low pass (210) includes a filter resistor (218) and capacitor (220) and is to filter the signal that eliminates the reflection produced when the switch (104) closed.

5. The switch protection system (100) as claimed in claim 1, in said switch protection system, If the value of the second voltage input is greater instead of the reference voltage input, the microcontroller unit (102) configured to detect switch (104) as closed: and If the value of the second voltage input is smaller instead of the reference voltage input, the microcontroller unit (102) configured to detect switch (104) as open.

6. The switch protection system (100) as claimed in claim 1, in said switch protection system, the module wetting current (112) is common to a plurality of n switches (104).

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