EMI filter circuit suitable for DC 24V power supply industrial personal computer

Abstract

The utility model relates to the technical field of industrial control, in particular to an EMI filter circuit suitable for a DC 24V power supply industrial personal computer, which comprises a bidirectional transient voltage suppressor diode, a CLC n-type filter, a chip inductor and a chip electrolytic capacitor which are connected in sequence, and the CLC n-type filter comprises a first chip capacitor, a common mode inductor and a second chip capacitor which are connected with one another; and the capacitance of the first chip capacitor is smaller than that of the second chip capacitor. The inductance value of the common mode inductor used by the circuit is far smaller than that of a traditional EMI filter circuit, the capacitance values of the two capacitors of the CLC n-type filter are small, and compared with the traditional EMI filter circuit, the CLC n-type filter and the CLC n-type filter have the great size advantage and are more suitable for the industrial personal computer board end with the limited overall space; in addition, the rated current of the common mode inductor and the chip inductor is larger, so that the applicable power range is wider.

Description

TECHNICAL FIELD

[0001] The utility model relates to industrial control technology field especially applicable to DC 24V power supply industrial computer's EMI filter circuit. BACKGROUND

[0002] Industrial computer is similar to light weight PC, generally, the factory will be attached with the matching power adapter. This kind of power adapter is generally the switching power supply of the commercial power to the specific DC voltage. Because this kind of switching power supply is the isolation power supply and has the special EMI filter circuit, therefore, under the condition of using the power adapter, the industrial computer board end does not need to add the EMI filter circuit again.

[0003] However, for the DC 24V power supply industrial computer, some work sites do not use the power adapter, but use the existing 24V directly. Under this condition, if the board end does not have the EMI filter circuit, the industrial computer can not work normally under the condition of the large power interference, and even appears the damage phenomenon. In order to solve this kind of condition, the EMI filter circuit must be added to the board end.

[0004] The existing EMI filter circuit is mostly for the power module, such as the EMI filter scheme matched with the Jinshengyang VRB2424 power module. The filtering effect of this kind of scheme is very good, and can cover almost any scene. However, this kind of scheme is difficult to use in the industrial computer board end, and the reasons are as follows:

[0005] 1, the Y capacitor is used for differential mode filtering, and the FG is needed on the board end, but some industrial computers do not set the FG, and the metal parts of the shell and each port are directly connected with the GND;

[0006] 2, the traditional EMI filter uses the common mode inductance with large inductance (generally mH level) to ensure the common mode filtering effect. For the 24V power supply, the peak current of the 60W rated power industrial computer is more than 3A, and the volume of the common mode inductance meeting the requirements is very large.

[0007] 3, the volume of the X capacitor meeting the requirements is too large, and if the chip capacitor is changed, the problem of insufficient voltage resistance of the large-capacity chip capacitor is easily faced.

[0008] Therefore, a new technical scheme is needed to solve the above technical problems. UTILITY MODEL CONTENT

[0009] The utility model aims at overcoming the problems of the prior art, and provides an EMI filter circuit applicable to the DC 24V power supply industrial computer, which is used to solve the technical problem that the existing EMI filter circuit is mostly for the power module and is difficult to use in the industrial computer board end.

[0010] The above object is achieved by the following technical solutions:

[0011] An EMI filter circuit suitable for a DC 24V power supply industrial computer, comprising a bidirectional transient voltage suppression diode, a CLC Π-type filter, a patch inductor and a patch electrolytic capacitor connected in sequence, the CLC Π-type filter comprising a first patch capacitor, a common mode inductor and a second patch capacitor connected with each other; the capacitance of the first patch capacitor is smaller than that of the second patch capacitor.

[0012] Further, the capacitance of the first patch capacitor is 0.1uF, and the capacitance of the second patch capacitor is 1uF-10uF.

[0013] Further, the second patch capacitor is further connected in parallel with a third patch capacitor.

[0014] Further, the model of the common mode inductor is PCAQ7060MW-701.

[0015] Further, a Schottky diode is further arranged between the bidirectional transient voltage suppression diode and the CLC Π-type filter.

[0016] Further, the model of the Schottky diode is SS10U45 / YANGJIE.

[0017] Further, the model of the bidirectional transient voltage suppression diode is SMDJ36CA.

[0018] Further, the model of the patch inductor is FXL0630.

[0019] Further, the capacitance of the patch electrolytic capacitor is 100uF-1000uF.

[0020] Further, the patch electrolytic capacitor is further connected in parallel with a fourth patch capacitor and a fifth patch capacitor.

[0021] The EMI filter circuit suitable for the DC 24V power supply industrial computer has simple structure, does not occupy space and has good use effect. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural schematic view of the EMI filter circuit suitable for the DC 24V power supply industrial computer. DETAILED DESCRIPTION

[0023] The utility model will be explained in further detail below according to the drawings and examples. The described examples are only a part of the examples of the utility model, not all examples. Based on the examples in the utility model, all other examples obtained by the ordinary skill in the art without making creative labor belong to the scope of protection of the utility model.

[0024] As Figure 1 The utility model provides a kind of EMI filter circuit suitable for DC 24V power supply industrial computer, including sequentially connected bidirectional transient voltage suppression diode D1, CLC Π type filter, patch inductance L1 and patch electrolytic capacitor E1, the CLC Π type filter includes mutually connected first patch capacitor C1, common mode inductance UL1 and second patch capacitor C2;

[0025] The capacitance of the first patch capacitor C1 is less than the capacitance of the second patch capacitor C2.

[0026] In this embodiment, the bidirectional transient voltage suppression diode D1 is used to prevent lightning surge;

[0027] The CLC Π type filter is used to filter common mode interference, wherein the first patch capacitor C1 at the front end of the CLC Π type filter is a small capacitor, used to filter high-frequency interference; the second patch capacitor C2 at the rear end of the CLC Π type filter is used to filter low-frequency interference.

[0028] The patch inductance L1 is used to filter differential mode interference.

[0029] The patch electrolytic capacitor E1 is used for further filtering.

[0030] In this embodiment, the capacitance of the first patch capacitor C1 is 0.1uF, and the capacitance of the second patch capacitor C2 is 1uF-10uF.

[0031] As an optimization of the present solution, a third patch capacitor C3 is also connected in parallel with the second patch capacitor C2, for further improving the ability to filter low-frequency interference. In this embodiment, the capacitance of the third patch capacitor C3 is 22uF.

[0032] In this embodiment, the common mode inductance UL1 is of model PCAQ7060MW-701, which is a common mode filter produced by PROD, mainly used for suppressing common mode noise to ensure the stability and reliability of the circuit. In addition, it also has good electrical performance and stability.

[0033] In the embodiment, a Schottky diode D2 is arranged between the bidirectional transient voltage suppression diode D1 and the CLC type filter, and is used for preventing user reverse connection input.

[0034] For the industrial computer, in order to prevent data loss caused by sudden power failure, a UPS or a lithium battery is generally provided, and the UPS or the lithium battery is charged when the power is turned on, and is discharged to the industrial computer when the power is turned off, so as to ensure normal shutdown and save data. The charging and discharging of the UPS are arranged at both ends of the Schottky diode, so as to effectively prevent the UPS or the lithium battery from being burned out.

[0035] As a specific embodiment of the present scheme, the Schottky diode D2 is of a SS10U45 / YANGJIE type.

[0036] In the embodiment, the bidirectional transient voltage suppression diode D1 is of an SMDJ36CA type. The bidirectional transient voltage suppression diode D1 can absorb high-energy transient voltage in a very short time, so as to protect other elements in the circuit from being damaged. The bidirectional conduction characteristic of the bidirectional transient voltage suppression diode D1 allows it to simultaneously protect positive and negative transient voltage surges. Whether the voltage is too high or too low, the bidirectional transient voltage suppression diode D1 can quickly respond and limit the voltage in a safe range.

[0037] In the embodiment, the chip inductor L1 is of an FXL0630 type.

[0038] In the embodiment, the chip electrolytic capacitor E1 has a capacitance of 100uF-1000uF, and is used for filtering more low-frequency interference.

[0039] As a specific embodiment of the present scheme, the chip electrolytic capacitor E1 has a specification of 100uF / 35V.

[0040] As a further optimization of the embodiment, the chip electrolytic capacitor E1 is further connected in parallel with a fourth chip capacitor C4 and a fifth chip capacitor C5. In the embodiment, the fourth chip capacitor C4 and the fifth chip capacitor C5 are reserved, and are used for expanding the capacitance by increasing the fourth chip capacitor C4 and the fifth chip capacitor C5 when the chip electrolytic capacitor E1 cannot select a large capacitance value due to height limitation.

[0041] The above merely describes the embodiments of the present application, and is not used for limiting the present application. For those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An EMI filter circuit suitable for a DC 24V powered industrial computer, characterized in that, It comprises a bidirectional transient voltage suppression diode (D1), a CLC Π filter, a patch inductor (L1) and a patch electrolytic capacitor (E1) connected in sequence, wherein the CLC Π filter comprises a first patch capacitor (C1), a common mode inductor (UL1) and a second patch capacitor (C2) connected with each other. The capacitance of the first patch capacitor (C1) is less than that of the second patch capacitor (C2).

2. The EMI filter circuit suitable for a DC 24V powered industrial computer according to claim 1, wherein, The capacitance of the first patch capacitor (C1) is 0.1uF, and the capacitance of the second patch capacitor (C2) is 1uF-10uF.

3. The EMI filter circuit suitable for a DC 24V powered industrial computer according to claim 1 or 2, characterized in that, The second patch capacitor (C2) is further connected in parallel with a third patch capacitor (C3).

4. The EMI filter circuit suitable for a DC 24V powered industrial computer according to claim 1 or 2, characterized in that, The common mode inductor (UL1) is of PCAQ7060MW-701.

5. The EMI filter circuit suitable for a DC 24V powered industrial computer according to claim 1, wherein, A Schottky diode (D2) is further arranged between the bidirectional transient voltage suppression diode (D1) and the CLC Π filter.

6. The EMI filter circuit suitable for a DC 24V powered industrial computer according to claim 5, wherein, The Schottky diode (D2) is of SS10U45 / YANGJIE.

7. The EMI filter circuit suitable for a DC 24V powered industrial computer according to claim 1, wherein, The bidirectional transient voltage suppression diode (D1) is of SMDJ36CA.

8. The EMI filter circuit suitable for a DC 24V powered industrial computer according to claim 1, wherein, The patch inductor (L1) is of FXL0630.

9. The EMI filter circuit suitable for a DC 24V powered industrial computer according to claim 1, wherein, The capacitance of the patch electrolytic capacitor (E1) is 100uF-1000uF.

10. The EMI filter circuit suitable for a DC 24V powered industrial computer according to claim 9, wherein, The patch electrolytic capacitor (E1) is further connected in parallel with a fourth patch capacitor (C4) and a fifth patch capacitor (C5).

Images