Current switching device for automobile emergency starting power supply

Abstract

A current switching device for an automobile emergency starting power supply comprises a lithium battery voltage sampling circuit used for collecting lithium battery voltage in the emergency starting power supply; the storage battery voltage sampling circuit is used for collecting the voltage of a storage battery on the automobile; the control module is used for outputting a first control signal and a second control signal based on the lithium battery voltage and the storage battery voltage; the pre-charging circuit is used for transmitting electric energy of a lithium battery of the emergency starting power supply to a storage battery based on a first current when the first control signal is at a high level; and the relay is used for transmitting the electric energy of the lithium battery of the emergency starting power supply to the storage battery based on the second current when the second control signal is the high level. According to the current switching device for the automobile emergency starting power supply provided by the utility model, the control module can conveniently and accurately sample the voltage of the automobile storage battery on line, so that the function of starting the automobile in emergency is stably realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of automobile emergency starting power supply, specifically to a current switching device for automobile emergency starting power supply. BACKGROUND

[0002] With the improvement of living demand level, people's possession quantity of automobile is increasing. Because the types of automobiles on the market are various, the quality of each part especially the battery assembly is different, and in addition to the incorrect use habits of different car owners, it is easy to lead to the performance decline of automobile battery, and it is easy to lose power and not start; In this case, emergency starting power supply is needed to quickly release the electric energy of lithium battery to the automobile battery in a short time to help start the automobile engine.

[0003] The key component of automobile emergency power supply is the intelligent switching circuit connected between the high-rate lithium battery and the automobile battery; the circuit not only needs to conduct hundreds of amperes of current instantaneously to provide the required electric energy for automobile starting, but also requires to provide various complete protection functions.

[0004] The intelligent clamp switching circuit scheme on the market generally uses a large-current DC relay to realize, which has great defects in technical design. Firstly, the main circuit is the on-off of the control ground loop, which brings inconvenience to the voltage sampling of the automobile battery, and also leads to the delay and precision reduction of voltage sampling, which further easily causes the starting current to not meet the demand; secondly, the relay is not effectively protected, which leads to the easy high-temperature adhesion of the relay contact and the loss of switching performance, greatly shortening the service life of the relay. UTILITY MODEL CONTENTS

[0005] In order to solve the problem of delay and precision reduction of voltage sampling in the prior art, the utility model provides a current switching device for automobile emergency starting power supply, which can conveniently and accurately sample the voltage of automobile battery online, thereby stably realizing the function of emergency starting automobile.

[0006] In order to realize the above-mentioned purpose, the utility model adopts the following specific scheme:

[0007] A current switching device for automobile emergency starting power supply, comprising:

[0008] A lithium battery voltage sampling circuit for collecting the voltage of lithium battery in the emergency starting power supply;

[0009] A battery voltage sampling circuit for collecting the voltage of battery on the automobile;

[0010] A control module for outputting first control signal and second control signal based on the lithium battery voltage and the battery voltage;

[0011] a pre-charge circuit for delivering the lithium battery power of the emergency starting power supply into the storage battery based on a first current when the first control signal is high;

[0012] a relay for delivering the lithium battery power of the emergency starting power supply into the storage battery based on a second current when the second control signal is high.

[0013] Preferably, the current switching circuit further comprises a contact temperature sampling circuit for collecting the contact temperature of the relay, and the contact temperature sampling circuit is connected to the control port of the control module.

[0014] Preferably, the contact temperature sampling circuit comprises a thermistor NTC5 and a capacitor C102, one end of the thermistor NTC5 is grounded, and the other end of the thermistor NTC5 and the other end of the capacitor C102 are connected to the control port of the control module.

[0015] Preferably, the current switching circuit further comprises an alarm circuit, and the alarm circuit is connected to the control port of the control module.

[0016] Preferably, the alarm circuit comprises a buzzer BUZ1, and the buzzer BUZ1 is connected to the control port of the control module.

[0017] Preferably, the lithium battery voltage sampling circuit comprises resistors R142 and R143 for voltage division, and the resistors R142 and R143 are connected in series, wherein the resistor R142 is connected to the positive electrode of the emergency starting power supply.

[0018] Preferably, the lithium battery voltage sampling circuit further comprises a diode ZD14, a capacitor C105 and a resistor R141, the diode ZD14, the capacitor C105 and one end of the resistor R141 are connected to the control port of the control module, the other end of the diode ZD14, the other end of the capacitor C105 and the resistor R143 are grounded, and the other end of the resistor R141 is connected between the resistor R142 and the resistor R143.

[0019] Preferably, the storage battery voltage sampling circuit comprises resistors R153 and R154 for voltage division, and the resistors R153 and R154 are connected in series, wherein the resistor R153 is connected to the positive electrode of the storage battery.

[0020] Preferably, the battery voltage sampling circuit further comprises a diode ZD15, a capacitor C115 and a resistor R155, one end of the diode ZD15, the capacitor C115 and the resistor R155 is connected with the control port of the control module, the other end of the capacitor C115, the other end of the diode ZD15 and the resistor R154 are grounded, and the other end of the resistor R155 is connected between the resistor R153 and the resistor R154.

[0021] Preferably, the current switching circuit further comprises an auxiliary power supply module, and the auxiliary power supply module is used for supplying power for the control module.

[0022] The utility model makes the emergency starting power supply and the automobile battery keep the same ground potential in whole process, makes the control module can conveniently sample the automobile battery voltage on line accurately, thereby stably realizes the function of starting the car in emergency, the utility model discloses through the pre-charging circuit parallelly connected between the relay contact, effectively reduces the voltage difference between the emergency starting power supply and the automobile battery, thereby reduces the arc column energy produced in the relay contact attraction moment, also correspondingly reduces the temperature rise of relay contact, reaches the purpose of protecting the relay contact, and further prolongs the service life of relay itself. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will briefly introduce the drawing needed to be used in the embodiment or prior art description, and obviously, the drawing in the following description is only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without paying creative labor.

[0024] Figure 1 It is the principle drawing of lithium battery voltage sampling circuit;

[0025] Figure 2 It is the principle drawing of battery voltage acquisition circuit;

[0026] Figure 3 It is the principle drawing of pre-charging circuit;

[0027] Figure 4 It is the principle drawing of temperature sampling circuit;

[0028] Figure 5 It is the principle drawing of relay;

[0029] Figure 6 It is the principle drawing of alarm circuit;

[0030] Figure 7 It is the principle drawing of control module. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0032] A current switching device for an automobile emergency starting power supply, comprising a lithium battery voltage acquisition circuit, a storage battery voltage acquisition circuit, a control module, a pre-charging circuit, a relay, a contact temperature sampling circuit, an alarm circuit and an auxiliary power supply module.

[0033] As shown in Figure 1 The lithium battery voltage sampling circuit is used for acquiring the lithium battery voltage in the emergency starting power supply. The lithium battery voltage sampling circuit comprises resistors R142 and R143 connected in series for voltage division, wherein the resistor R142 is connected with the positive electrode of the emergency starting power supply. More specifically, the lithium battery voltage sampling circuit further comprises a diode ZD14, a capacitor C105 and a resistor R141. One end of the diode ZD14, the capacitor C105 and the resistor R141 is connected and then connected with the control port of the control module. The other end of the diode ZD14, the other end of the capacitor C105 and the resistor R143 are grounded. The other end of the resistor R141 is connected between the resistor R142 and the resistor R143.

[0034] As shown in Figure 2 The storage battery voltage sampling circuit is used for acquiring the storage battery voltage on the automobile. The storage battery voltage sampling circuit comprises resistors R153 and R154 connected in series for voltage division, wherein the resistor R153 is connected with the positive electrode of the storage battery of the automobile. More specifically, the storage battery voltage sampling circuit further comprises a diode ZD15, a capacitor C115 and a resistor R155. One end of the diode ZD15, the capacitor C115 and the resistor R155 is connected and then connected with the control port of the control module. The other end of the capacitor C115, the other end of the diode ZD15 and the resistor R154 are grounded. The other end of the resistor R155 is connected between the resistor R153 and the resistor R154.

[0035] As shown in Figure 7 The control module is used for outputting a first control signal EN_RLS and a second control signal EN_OUT based on the lithium battery voltage and the storage battery voltage. The current switching circuit further comprises an auxiliary power supply module U10, which is used for supplying power to the control module.

[0036] As shown in Figure 3As shown in FIG. 6, the pre-charge circuit is used to deliver the lithium battery power of the emergency starting power supply into the battery based on the first current when the first control signal EN_RLS is high. More specifically, the pre-charge circuit further includes diode D17, resistor R148, resistor R149, resistor R150, resistor R151, resistor R152, transistor Q35 and transistor Q36.

[0037] As shown in FIG. 6, the pre-charge circuit is used to deliver the lithium battery power of the emergency starting power supply into the battery based on the first current when the first control signal EN_RLS is high. More specifically, the pre-charge circuit further includes diode D17, resistor R148, resistor R149, resistor R150, resistor R151, resistor R152, transistor Q35 and transistor Q36. Figure 5 As shown in FIG. 6, the pre-charge circuit is used to deliver the lithium battery power of the emergency starting power supply into the battery based on the first current when the first control signal EN_RLS is high. More specifically, the pre-charge circuit further includes diode D17, resistor R148, resistor R149, resistor R150, resistor R151, resistor R152, transistor Q35 and transistor Q36.

[0038] The current switching circuit further includes a contact temperature sampling circuit used to collect the contact temperature of the relay, and the contact temperature sampling circuit is connected with the control port of the control module.

[0039] As shown in FIG. 6, the pre-charge circuit is used to deliver the lithium battery power of the emergency starting power supply into the battery based on the first current when the first control signal EN_RLS is high. More specifically, the pre-charge circuit further includes diode D17, resistor R148, resistor R149, resistor R150, resistor R151, resistor R152, transistor Q35 and transistor Q36. Figure 4 As shown in FIG. 6, the pre-charge circuit is used to deliver the lithium battery power of the emergency starting power supply into the battery based on the first current when the first control signal EN_RLS is high. More specifically, the pre-charge circuit further includes diode D17, resistor R148, resistor R149, resistor R150, resistor R151, resistor R152, transistor Q35 and transistor Q36.

[0040] Figure 6 As shown in FIG. 6, the pre-charge circuit is used to deliver the lithium battery power of the emergency starting power supply into the battery based on the first current when the first control signal EN_RLS is high. More specifically, the pre-charge circuit further includes diode D17, resistor R148, resistor R149, resistor R150, resistor R151, resistor R152, transistor Q35 and transistor Q36.

[0041] ​The utility model discloses a control module first through the resistance R142 and the resistance R143 sampling lithium battery voltage in emergency starting power supply when detecting that lithium battery voltage is below 10.5V or is higher than 17.5V, the second control signal EN_OUT of control module output is low level, and the relay is disconnected, and enters the protection state, and the buzzer BUZ1 of alarm circuit emits the sound alarm simultaneously. It needs to be explained that the situation of power voltage below 10.5V also includes the 0V situation of short circuit. When emergency starting power supply is connected with the car battery, control module passes through the resistance R153 and the resistance R154 of battery voltage acquisition circuit and gathers the battery voltage, and then there are two states. The first state is when detecting that the battery voltage is greater than 18V, the second control signal EN_OUT of control module output is low level, and the relay is not attracted, enters the protection state, and the buzzer BUZ1 alarm simultaneously, the second state is when detecting that the battery voltage is higher than lithium battery voltage, the second control signal EN_OUT of control module output is low level, and the relay is disconnected, but at this moment, the car can be started normally. On the other hand, when emergency starting power supply is connected with the car battery, and the battery voltage is below the preset threshold, the first control signal EN_RLS of control module output is high level, and the triode Q35 and the triode Q36 are turned on, and the emergency starting power supply carries out the current limiting charging to the battery through the resistance R148, that is, based on the first current and charges the battery, when the voltage difference AV between lithium battery voltage and battery voltage gradually reduces to the preset threshold, the second control signal EN_OUT becomes high level, and the relay is attracted, and the emergency starting power supply releases hundreds of ampere current instantaneously, and helps to start the car engine. Conversely, if the detected battery voltage is in the normal value range and is normally connected, the second control signal EN_OUT is high level, and the relay is attracted, and the battery does not need to be current limiting charged through the pre-charging circuit in the process.

[0042] During the whole use, temperature sampling circuit continuously detects the temperature at the relay contact pad, when the pad temperature reaches the over-temperature protection point 130 DEG C, AD_NTC voltage changes from 4V to 1V, at this time, the second control signal EN_OUT flips to low level, the relay is disconnected, the output is closed, and the function of output over-current protection is realized.

[0043] When detecting that lithium battery voltage is overvoltage or undervoltage, the battery is reversed or short-circuited, the temperature is too high, and the starting time is too long, the BUZZER is high level, the triode Q34 is turned on, the buzzer BUZ1 is powered on and emits an alarm sound, reminding the operator to handle in time.

[0044] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same or similar parts of each embodiment can be referred to each other.

[0045] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A current switching device for an automotive emergency jump starting power source, characterized by, The current switching device comprises: a lithium battery voltage sampling circuit for collecting the voltage of a lithium battery in an emergency starting power supply; a storage battery voltage sampling circuit for collecting the voltage of a storage battery on a vehicle; a control module for outputting a first control signal and a second control signal based on the lithium battery voltage and the storage battery voltage; a pre-charge circuit for delivering the lithium battery power of the emergency starting power supply to the storage battery based on a first current when the first control signal is high; a relay for delivering the lithium battery power of the emergency starting power supply to the storage battery based on a second current when the second control signal is high.

2. A current switching device for an automotive emergency starting power supply as defined in claim 1, characterized in that The current switching device further comprises a contact temperature sampling circuit for collecting the contact temperature of the relay, and the contact temperature sampling circuit is connected to the control port of the control module.

3. A current switching device for an automotive emergency start power supply as defined in claim 2, characterized in that The contact temperature sampling circuit comprises a thermistor NTC5 and a capacitor C102, one end of the thermistor NTC5 is grounded, and the other end of the thermistor NTC5 and the other end of the capacitor C102 are connected and then connected to the control port of the control module.

4. The current switching device for an automotive emergency starting power supply of claim 1, wherein, The current switching device further comprises an alarm circuit, and the alarm circuit is connected to the control port of the control module.

5. A current switching device for an automotive emergency start power supply as defined in claim 4, wherein The alarm circuit comprises a buzzer BUZ1, and the buzzer BUZ1 is connected to the control port of the control module.

6. A current switching device for an automotive emergency starting power supply as defined in claim 1, wherein The lithium battery voltage sampling circuit comprises resistors R142 and R143 for voltage division, and the resistors R142 and R143 are connected in series, wherein the resistor R142 is connected to the control port of the emergency starting power supply.

7. A current switching device for an automotive emergency start power supply as defined in claim 6, wherein The lithium battery voltage sampling circuit further comprises a diode ZD14, a capacitor C105 and a resistor R141, one end of the diode ZD14, the capacitor C105 and the resistor R141 is connected and then connected to the control port of the control module, the other end of the diode ZD14, the other end of the capacitor C105 and the resistor R143 are grounded, and the other end of the resistor R141 is connected between the resistor R142 and the resistor R143.

8. A current switching device for an automotive emergency starting power supply as defined in claim 1, wherein The storage battery voltage sampling circuit comprises resistors R153 and R154 for voltage division, and the resistors R153 and R154 are connected in series, wherein the resistor R153 is connected to the positive electrode of the storage battery of the vehicle.

9. A current switching device for an automotive emergency starting power supply as defined in claim 7, wherein The storage battery voltage sampling circuit further comprises a diode ZD15, a capacitor C115 and a resistor R155, one end of the diode ZD15, the capacitor C115 and the resistor R155 is connected and then connected to the control port of the control module, the other end of the capacitor C115, the other end of the diode ZD15 and the resistor R154 are grounded, and the other end of the resistor R155 is connected between the resistor R153 and the resistor R154.

10. The current switching device for an automotive emergency starting power supply of claim 1, wherein, The current switching device further comprises an auxiliary power supply module for supplying power to the control module.

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