Vehicle-mounted protection circuit for coping with alternating current superposition test and load rejection

Abstract

The utility model discloses a vehicle-mounted protection circuit for coping with alternating current superposition test and load rejection, which is arranged in a vehicle-mounted power supply and comprises a reverse energy cut-off diode D and a load rejection energy absorption diode DZ. The anode of the reverse energy cut-off diode D is connected with the positive end of power supply input, and the cathode of the reverse energy cut-off diode D is connected with a load. And the load throwing energy absorption diode DZ is connected to the two ends of the power supply. According to the design of a vehicle-mounted use environment, the reverse cut-off diode and the throw load energy absorption diode are adopted, a perfect protection effect is achieved, a power supply of the protection circuit can still work stably even in a most strict superposition alternating current test and a throw load test, additionally arranged devices are small in size and low in cost, and the cost is low. The effect ratio is extremely high.

Description

TECHNICAL FIELD

[0001] The utility model relates to vehicle-mounted power protection technical field especially relates to a vehicle-mounted protection circuit of response alternating current superposition test and throw load. BACKGROUND

[0002] On the mobile public transport tools such as bus, bus, train, cruise ship, vehicle-mounted power supply will be provided for multimedia entertainment display. Because the vehicle use environment is relatively complex, the automobile engine starts instantaneous and the off instantaneous will produce very high voltage difference, like this easily leads to the power failure of multimedia display. And the voltage, current of starting generator power supply in the car often appears not smooth (such as overvoltage, undervoltage), lead to the partial electronic components of multimedia display damage, thus need to increase protection circuit for vehicle-mounted power supply.

[0003] In the GB / T28046 alternating current superposition test of vehicle-mounted power supply, the most severe is 10V / 20Hz test, this tests the power supply in the alternating current condition alternating current bearing capacity, in ISO 7637-2 5b throw load test, the most severe is 200V test, test the power supply in the high voltage input situation bearing capacity. For the above two extreme tests, the vehicle-mounted power supply of prior art performs badly. SUMMARY

[0004] In view of above technical problem, the utility model provides a vehicle-mounted protection circuit of response alternating current superposition test and throw load to solve above insufficient.

[0005] Other characteristics and advantages of the present disclosure will become apparent from the following detailed description, or will be learned by practice of the present disclosure.

[0006] A vehicle-mounted protection circuit of response alternating current superposition test and throw load, the protection circuit is arranged between the power supply of vehicle-mounted equipment and its post-stage load, the protection circuit includes reverse energy cut-off diode and throw load energy absorption diode, the throw load energy absorption diode is connected in parallel on the loop of the power supply and the post-stage load, the anode of the reverse energy cut-off diode is connected the power supply, and its cathode is connected the post-stage load.

[0007] The technical scheme of the present disclosure has the following beneficial effects:

[0008] According to the design of vehicle-mounted use environment, adopt reverse cut-off diode and throw load energy absorption diode, have perfect protection effect, even in the most severe superposition alternating current test and throw load test, the power supply of protection circuit still can steady work, and the volume of the device added is small, and the cost is low, and the effect ratio is extremely high. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 The structure block diagram of the vehicle-mounted protection circuit for dealing with alternating current superposition test and throw load in the embodiment of the present specification is shown in the figure;

[0010] Figure 2 The circuit principle diagram of the vehicle-mounted protection circuit for dealing with alternating current superposition test and throw load in the embodiment of the present specification is shown in the figure;

[0011] Figure 3 The test effect diagram of the vehicle-mounted device applying the protection circuit in the embodiment of the present specification is shown in the figure;

[0012] Figure 4 The test effect diagram of the vehicle-mounted device applying the protection circuit in the embodiment of the present specification is shown in the figure. DETAILED DESCRIPTION

[0013] The technical scheme of the present application will be described clearly and completely in combination with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, instead of all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0014] As shown in the figure, Figure 1 the present specification provides a vehicle-mounted protection circuit for dealing with alternating current superposition test and throw load. The protection circuit is arranged between the power supply 1 of the vehicle-mounted device and the subsequent load 4. The protection circuit comprises a reverse energy cutoff diode 3 and a throw load energy absorption diode 2. The throw load energy absorption diode 2 is connected in parallel to the loop of the power supply 1 and the subsequent load 4. The anode of the reverse energy cutoff diode 3 is connected to the power supply 1, and the cathode is connected to the subsequent load 4.

[0015] Specifically, as shown in the figure, Figure 2 the reverse energy cutoff diode is D, and the throw load energy absorption diode is DZ. When superimposed alternating current test is performed (20 Hz / 10 V), according to Figure 3 , without the protection circuit, the peak-to-peak value of the input current reaches 90 A, and the root mean square value is 63.65 A. This will cause huge power loss to the power input line, the fuse tube, the power line and the power device, and in severe cases, the fuse tube will be blown and the device will be damaged. After adding the reverse cutoff diode D, according to Figure 4 , the reverse alternating current is eliminated due to the addition of the reverse reverse energy cutoff diode, and the forward alternating current is also reduced due to the addition of the reverse energy cutoff diode D, with a peak-to-peak value of only 6 A and a root mean square current of 2.12 A. Compared with the input current without the reverse energy cutoff diode D, the input current is significantly reduced.

[0016] When the throw load test is carried out (7637 / 5b / 200V), the peak-peak value of the input voltage can reach 224V without the protection circuit, which is unbearable for the 24V input power supply and the power supply will be seriously damaged. After adding the throw load energy absorption diode DZ, the input voltage peak-peak value can be significantly reduced to 40-50V, which can be tolerated by the power supply, and the effect is obviously improved.

[0017] From the above, according to the design of the vehicle-mounted use environment, the reverse blocking diode and the throw load energy absorption diode are adopted, which has perfect protection effect, that is, even in the most severe superimposed alternating current test and throw load test, the power supply of the protection circuit can still work stably, and the volume of the added device is small, the cost is low, and the effect is extremely high

[0018] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application. In addition, those skilled in the art can understand that although some of the embodiments described herein include certain features rather than others, the combination of features of different embodiments means that it is within the scope of the present application and forms different embodiments. For example, in the above claims, any one of the claimed embodiments can be used in any combination. The information disclosed in the background section is only intended to deepen the understanding of the overall background of the present application, and should not be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A vehicle-mounted protection circuit for coping with alternating current superimposed test and throw load, characterized in that, The protection circuit is arranged between a power supply and a load of a vehicle-mounted device, and comprises a reverse energy cutoff diode and a throw load energy absorption diode, the throw load energy absorption diode is connected in parallel to a loop of the power supply and the load, and the anode of the reverse energy cutoff diode is connected to the power supply and the cathode is connected to the load.

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