Electrician measurement protection power supply

Abstract

The electrician measurement protection power supply comprises a shell, first fixing blocks are arranged at the centers of the tops of the two sides of the shell, a shell cover is arranged at the top of the shell, first fixing blocks are arranged at the centers of the bottoms of the two sides of the shell cover, and the first fixing blocks and second fixing blocks are connected through fixing bolts. A heat dissipation fan is arranged in the center of the bottom of the shell, a supporting plate is arranged on the top of the heat dissipation fan, an isolation transformer and a current-limiting resistor are arranged on the top of the supporting plate, and power consumed by an electrical wiring board is limited and is current needed by attraction of a contactor in the testing process, so that the two ends of the current-limiting resistor almost have no voltage drop; and the influence on the input of the transformer is very small. If the detected circuit board is short-circuited, the real short circuit cannot be caused due to the existence of the current-limiting resistor. The short circuit phenomenon of the tested circuit can be rapidly observed through the voltage indicating gauge, the QF switch is timely switched off, and safety is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical engineering teaching, in particular to an electrical engineering measurement and protection power supply. Background Art

[0002] When students begin electrical wiring exercises, incorrect wiring can create short circuits, posing a safety hazard when the power is turned on. Consequently, when guiding students through these exercises, teachers often simply measure the resistance change between the wires, rather than conducting power tests. This is inconsistent with the requirements for talent development. Some believe that simply adding a suitable circuit breaker can prevent the hazards of a short circuit. However, this is not appropriate. Furthermore, tripping this circuit breaker cannot completely prevent tripping the circuit breaker in the entire classroom or even on the entire floor. Even if it could, it would be an unconventional approach. Utility Model Content

[0003] The purpose of the utility model is to provide an electrical measurement protection power supply to solve the problems raised in the above background technology.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] An electrical measurement protection power supply includes a housing, a housing cover, and an internal circuit. The housing has an inner cavity formed on the top. First fixing blocks are provided at the top centers of both ends of the housing. Second fixing blocks are provided on top of the first fixing blocks. The inner sides of the two second fixing blocks are respectively connected to the top centers of two different ends of the housing cover.

[0006] A circular hole is provided at the center of the bottom of the shell, and a cooling fan is fixedly connected to the inside of the circular hole, the bottom of the cooling fan is located below the bottom of the shell, and the top of the cooling fan is located above the bottom of the inner cavity of the shell, a support plate is provided on the top of the cooling fan, the surface of the support plate is connected to the inner cavity wall of the shell, and cooling fan exchange ports are provided at the top and bottom of the support plate and at the cooling fan, and exchange ports are provided at other parts of the top and bottom of the support plate, and an internal circuit is provided on the top of the support plate, and the internal circuit includes a first interface, a second interface, a QF switch, a current limiting resistor, an isolation transformer, and a voltage indicator, the first interface is connected in series with the QF switch, the QF switch is connected in series with the current limiting resistor, the current limiting resistor is connected in series with the isolation transformer, the output end of the isolation transformer is connected in series with the second interface, and the output end of the isolation transformer is connected in parallel with the voltage indicator.

[0007] Preferably, fixing holes are provided through the centers of the tops and bottoms of the first fixing block and the second fixing block, and fixing bolts are provided inside the fixing holes.

[0008] Preferably, a plurality of heat dissipation openings are provided on the front and back of the housing.

[0009] Preferably, support pads are provided at the four corners of the bottom of the shell, and the bottom of the support pads is located below the bottom of the cooling fan.

[0010] Preferably, a first air inlet and outlet and a second air inlet and outlet are respectively provided at the bottom center of both sides of the shell, and the first air inlet and outlet and the second air inlet and outlet are connected by a guide groove, the bottom of the guide groove is located at the bottom of the inner cavity of the shell, and the top of the guide groove is connected to the bottom of the support plate.

[0011] Preferably, a first through hole is provided at the center of one side of the shell, the first through hole is connected to a first interface, and the first interface is connected to a three-phase power supply.

[0012] Preferably, a second through hole is provided at the center of the other side of the housing, the second through hole is connected to the second interface, and the second interface is connected to the circuit board to be tested.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] The utility model discloses an electrician measurement protection power supply, which utilizes a 380V / 300VA three-phase isolation transformer and adds a current-limiting resistor to the front end of the isolation transformer. Since the power consumed by the electrician's terminal block is very limited, that is, the current required for the contactor to attract during testing, there is almost no voltage drop across the current-limiting resistor, and the impact on the transformer input is very small. If the circuit board under test is short-circuited, the presence of the current-limiting resistor will not cause a real short circuit. The voltage indicator can quickly observe the short circuit phenomenon of the circuit under test and disconnect the QF switch in time. Of course, even if the short circuit lasts for a certain period of time, it will not cause damage to the circuit, and will not create a psychological burden on the operation of teachers and students. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the internal circuit structure of the housing of the utility model;

[0016] Figure 2 This is a schematic diagram of the front structure of the shell and shell cover of the utility model;

[0017] Figure 3 This is a schematic diagram of the bottom structure of the shell and shell cover of the present utility model;

[0018] Figure 4 This is a schematic diagram of the internal structure of the shell of the present utility model.

[0019] In the figure: 1. Shell; 2. First interface; 3. QF switch; 4. Current-limiting resistor; 5. Isolation transformer; 6. Voltage indicator; 7. Second interface; 8. First air inlet and outlet; 9. First through hole; 10. Heat dissipation vent; 11. First fixing block; 12. Second fixing block; 13. Fixing hole; 14. Shell cover; 15. Cooling fan; 16. Support pad; 17. Second air inlet and outlet; 18. Second through hole; 19. Support plate; 20. Exchange port; 21. Cooling fan exchange port; 22. Guide groove. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that the terms "vertical", "up", "down", "horizontal", etc. indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0022] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0023] See also Figure 1-4 , the utility model provides a technical solution:

[0024] An electrical measurement and protection power supply includes a housing 1, a housing cover 14, and an internal circuit. The housing 1 has an inner cavity formed on the top. First fixing blocks 11 are provided at the top centers of both ends of the housing 1. Second fixing blocks 12 are provided on top of the first fixing blocks 11. The inner sides of the two second fixing blocks 12 are respectively connected to the top centers of two different ends of the housing cover 14.

[0025] A circular hole is provided at the center of the bottom of the shell 1, and a cooling fan 15 is fixedly connected to the inside of the circular hole. The bottom of the cooling fan 15 is located below the bottom of the shell 1, and the top of the cooling fan 15 is located above the bottom of the inner cavity of the shell 1. A support plate 19 is provided on the top of the cooling fan 15, and the surface of the support plate 19 is connected to the inner cavity wall of the shell 1. A cooling fan exchange port 21 is provided at the top and bottom of the support plate 19 and located at the cooling fan 15, and an exchange port 20 is provided at other parts of the top and bottom of the support plate 19. An internal circuit is provided on the top of the support plate 19, and the internal circuit includes a first interface 2, a second interface 7, a QF switch 3, a current limiting resistor 4, an isolation transformer 5, and a voltage indicator 6. The first interface 2 is connected in series with the QF switch 3, the QF switch 3 is connected in series with the current limiting resistor 4, the current limiting resistor 4 is connected in series with the isolation transformer 5, the output end of the isolation transformer 5 is connected in series with the second interface 7, and the output end of the isolation transformer 5 is connected in parallel with the voltage indicator 6.

[0026] The present invention utilizes a 380V / 300VA three-phase isolation transformer 5 and incorporates a current-limiting resistor 4 at the front end of the isolation transformer 5. Because the power consumed by the electrical wiring board is very limited—the current required to close the contactor during testing—there is virtually no voltage drop across the current-limiting resistor 4, minimizing the impact on the input of the isolation transformer 5. If the circuit board under test shorts, the presence of the current-limiting resistor 4 prevents a true short circuit. The voltage indicator 6 allows for quick detection of short circuits in the circuit under test and for timely disconnection of the QF switch 3. Even if a short circuit persists for a certain period of time, it will not damage the circuit and pose no psychological burden to teachers or students.

[0027] In addition, the current limiting resistor 4 uses a 10*100 220V, 250W electric heating rod.

[0028] Furthermore, fixing holes 13 are formed through the top and bottom centers of the first fixing block 11 and the second fixing block 12 . Fixing bolts are provided inside the fixing holes 13 to fix the shell cover 14 to the housing 1 .

[0029] Furthermore, a plurality of heat dissipation openings 10 are provided on the front and back of the housing 1 , which can further discharge heat and improve the heat dissipation performance of the housing 1 .

[0030] Furthermore, support pads 16 are provided at the four corners of the bottom of the housing 1 , and the bottom of the support pads 16 is located below the bottom of the cooling fan 15 .

[0031] Furthermore, a first air inlet and outlet 8 and a second air inlet and outlet 17 are respectively provided at the bottom center of both sides of the shell 1. The first air inlet and outlet 8 and the second air inlet and outlet 17 are connected by a guide groove 22. The bottom of the guide groove 22 is located at the bottom of the inner cavity of the shell 1, and the top of the guide groove 22 is connected to the bottom of the support plate 19.

[0032] Furthermore, a first through hole 9 is provided at the center of one side of the housing 1 . The first through hole 9 is connected to the first interface 2 , and the first interface 2 is connected to a three-phase power supply.

[0033] Furthermore, a second through hole 18 is provided at the center of the other side of the housing 1 . The second through hole 18 is connected to the second interface 7 , and the second interface 7 is connected to the circuit board to be tested.

[0034] If the circuit board being practiced has a motor load, the present invention can also be used, because the motor power used in the practice is not large and is all no-loaded, and the current is not large, but at this time it is necessary to adjust the resistance value of the current limiting resistor 4, and a lot of heat will be generated at this time, and it is also necessary to improve the heat dissipation. In order to be able to use the present invention when replacing different circuit boards, a heat dissipation structure is provided at the housing, and the heat dissipation structure includes a heat dissipation fan 15, wherein the heat dissipation fan 15 is a commonly used heat dissipation method in the prior art and is an existing mature technology, and its electrical connection will not be discussed here. The system and the specific circuit structure are described in detail. In addition, a guide groove 22 is provided in other parts of the cooling fan 15. The two sides of the guide groove 22 are respectively connected to the two sides of the shell 1, and openings are provided at the connection, which are the first air inlet and outlet 9 and the second air inlet and outlet 17. If the wind enters from the first air inlet and outlet 9 and flows out from the second air inlet and outlet 17, in the process of flowing from the first air inlet and outlet 9 to the second air inlet and outlet 17, it will flow in the guide groove 22. At this time, the hot air in the shell 1 and above the support plate 19 will exchange heat with this wind, which is convenient for discharging heat.

[0035] When the utility model is used on different circuit boards, it is only necessary to adjust the current limiting resistor 4 .

[0036] It is worth noting that the entire device is controlled by a controller. Since the controller is a commonly used device and belongs to existing mature technology, its electrical connection relationship and specific circuit structure will not be described in detail here.

[0037] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electrical measurement protection power supply, comprising a housing (1), a housing cover (14), and an internal circuit, characterized in that: The shell (1) has an inner cavity at the top, and first fixing blocks (11) are provided at the top of the centers of both ends of the shell (1). A second fixing block (12) is provided on the top of the first fixing block (11), and the inner sides of the two second fixing blocks (12) are respectively connected to the top centers of two different ends of the shell cover (14); A circular hole is provided at the center of the bottom of the shell (1), and a cooling fan (15) is fixedly connected to the inside of the circular hole. The bottom of the cooling fan (15) is located below the bottom of the shell (1), and the top of the cooling fan (15) is located above the bottom of the inner cavity of the shell (1). A support plate (19) is provided on the top of the cooling fan (15), and the surface of the support plate (19) is connected to the inner cavity wall of the shell (1). A cooling fan exchange port (21) is provided at the top and bottom of the support plate (19) and at the cooling fan (15). The top and bottom of the support plate (19) and other parts are provided with an exchange port. The switch port (20) is provided with an internal circuit on the top of the support plate (19), and the internal circuit includes a first interface (2), a second interface (7), a QF switch (3), a current limiting resistor (4), an isolation transformer (5), and a voltage indicator (6). The first interface (2) is connected in series with the QF switch (3), the QF switch (3) is connected in series with the current limiting resistor (4), the current limiting resistor (4) is connected in series with the isolation transformer (5), the output end of the isolation transformer (5) is connected in series with the second interface (7), and the output end of the isolation transformer (5) is connected in parallel with the voltage indicator (6).

2. The electrical measurement protection power supply according to claim 1, characterized in that: Fixing holes (13) are provided through the top and bottom centers of the first fixing block (11) and the second fixing block (12), and fixing bolts are provided inside the fixing holes (13).

3. The electrical measurement protection power supply according to claim 1, characterized in that: A plurality of heat dissipation openings (10) are provided on the front and back of the housing (1).

4. The electrical measurement protection power supply according to claim 1, characterized in that: Support pads (16) are provided at the four corners of the bottom of the housing (1), and the bottom of the support pad (16) is located below the bottom of the cooling fan (15).

5. The electrical measurement protection power supply according to claim 1, characterized in that: A first air inlet and outlet (8) and a second air inlet and outlet (17) are respectively provided at the center of the bottom of both sides of the shell (1); the first air inlet and outlet (8) and the second air inlet and outlet (17) are connected via a guide groove (22); the bottom of the guide groove (22) is located at the bottom of the inner cavity of the shell (1); and the top of the guide groove (22) is connected to the bottom of the support plate (19).

6. The electrical measurement protection power supply according to claim 1, characterized in that: A first through hole (9) is provided at the center of one side of the housing (1); the first through hole (9) is connected to a first interface (2); and the first interface (2) is connected to a three-phase power supply.

7. The electrical measurement protection power supply according to claim 1, characterized in that: A second through hole (18) is provided at the center of the other side of the housing (1), the second through hole (18) is connected to the second interface (7), and the second interface (7) is connected to the circuit board to be tested.

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