Signal switching circuit and signal switching jig

Abstract

The invention provides a test fixture and a signal switching fixture. The signal switching jig is connected between the oscilloscope and the N signal input sources. The signal switching circuit comprises N input ends which are respectively connected with N signal input sources in a one-to-one correspondence manner; the output end is used for being connected to a channel of an oscilloscope; and (N-1) switching units, wherein each switching unit comprises a normally closed end, a common end, a normally open end and a control end. The signal switching circuit provided by the invention can effectively improve the test efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of testing, in particular to a signal switching circuit and a signal switching jig. BACKGROUND

[0002] An oscilloscope can be used to observe the waveform curve of the amplitude of different signals changing with time, and can also be used to test various electrical quantities such as voltage, current, frequency, phase difference, amplitude modulation, etc. However, the existing general-purpose oscilloscope includes a limited number of channels, which results in the need for multiple plugging and unplugging when a large number of signals to be measured are measured, thereby reducing the testing efficiency. SUMMARY

[0003] Therefore, the present application provides a signal switching circuit and a signal switching jig, which can simplify manual operation, improve testing efficiency and reduce testing cost.

[0004] The present application provides a signal switching circuit connected between an oscilloscope and N signal input sources. The signal switching circuit comprises: N input terminals respectively connected in one-to-one correspondence with the N signal input sources; an output terminal for connecting to a channel of the oscilloscope; N-1 switching units, each switching unit comprising a normally closed terminal, a common terminal, a normally open terminal and a control terminal, N-1 common terminals are respectively connected in one-to-one correspondence with N-1 input terminals, the normally open terminal of each switching unit is connected with the common terminal of the adjacent switching unit in turn to form a signal path, the common terminal of one end of the signal path is connected with the output terminal, and the normally open terminal of the other end of the signal path is connected with the Nth input terminal, wherein the control terminal is used for receiving a control signal, and when the control signal is a first level signal, the normally closed terminal is connected with the common terminal, and the normally open terminal is disconnected with the common terminal, and when the control signal is a second level signal, the normally closed terminal is disconnected with the common terminal, and the normally open terminal is connected with the common terminal, and the signal switching circuit acquires a signal input by a signal input source from the N input terminals according to the control signal received by each control terminal and outputs the signal to the oscilloscope through the output terminal.

[0005] In one embodiment, the normally open terminal includes a first normally open contact and a second normally open contact, the common terminal includes a first common contact and a second common contact, and the normally closed terminal includes a first normally closed contact and a second normally closed contact. The first common contact at one end of the signal path is connected to the first end of the output terminal, and the second common contact at one end of the signal path is also connected to the second end of the output terminal. The first normally open contact of the switching unit at the other end of the signal path is connected to the first end of the corresponding input terminal, and the second normally open contact of the switching unit at the other end of the signal path is connected to the second end of the corresponding input terminal. The first normally open contact in each of the remaining switching units is connected to the first common contact of the adjacent switching unit, and the second normally open contact in each of the remaining switching units is connected to the second common contact of the adjacent switching unit. The first normally closed contact in each switching unit is connected to the first common contact, and the first normally closed contact in each switching unit is also connected to the first end of the corresponding input terminal. The second normally closed contact in each switching unit is connected to the second common contact, and the second normally closed contact in each switching unit is also connected to the second end of the corresponding input terminal.

[0006] In one embodiment, the signal switching circuit further includes a power supply, and each switching unit further includes a switching transistor, a first connection terminal, and a second connection terminal. In each switching unit, the first connection terminal is connected to the first terminal of the switching transistor, the second connection terminal is connected to the first connection terminal, the second connection terminal is connected to the positive terminal of the power supply, the negative terminal of the power supply is connected to the second terminal of the switching transistor, and the third terminal of the switching transistor is connected to the control terminal.

[0007] In one embodiment, each switching unit further includes a first current-limiting resistor, a second current-limiting resistor, and a diode. In each switching unit, the second connection terminal is connected to the first connection terminal through the first current-limiting resistor, the anode of the diode is connected between the first terminal of the switching transistor and the first connection terminal, the cathode of the diode is connected to the second connection terminal, and the third terminal of the switching transistor is connected to the control terminal through the second current-limiting resistor.

[0008] In one embodiment, each switching unit further includes a connection port, a first end of which is connected between a first normally closed contact and a first end of a correspondingly connected input terminal, and a second end of which is connected between a second normally closed contact and a second end of a correspondingly connected input terminal.

[0009] This application provides a signal switching fixture, including a controller and at least one signal switching circuit as described in any of the preceding claims. The controller is electrically connected to the control terminal of each of the switching units and is used to output a control signal to each control terminal.

[0010] In one embodiment, the signal switching fixture includes a plurality of circuit boards, each circuit board being used to carry at least one signal switching circuit.

[0011] In one embodiment, the circuit board includes a first side, a second side and a third side adjacent to the first side, the output terminals of two signal switching circuits are disposed on the first side, all input terminals of one signal switching circuit are disposed on the second side, and all input terminals of the other signal switching circuit are disposed on the third side.

[0012] In one embodiment, the signal switching fixture further includes a support frame disposed between two circuit boards, such that the circuit boards are stacked and spaced apart.

[0013] In one embodiment, the signal switching fixture further includes a frame for accommodating at least one signal switching circuit and a controller. The frame has a plurality of slots, and the plurality of slots correspond to the input and output terminals of the at least one signal switching circuit.

[0014] The signal switching circuit provided in this application, by setting an output terminal, N input terminals, and N-1 switching units, and by controlling the N-1 switching units, allows each of the N-1 switching units to obtain one input signal from N signal input sources connected to the N input terminals, and output it to the oscilloscope through the output terminal. Thus, the signal switching circuit provided in this application not only reuses the signal input channels of the oscilloscope, but also reduces the number of circuit plugging and unplugging operations when testing multiple signal input sources, thereby improving testing efficiency. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be considered as a limitation on the scope of protection of this application. In the various drawings, similar components are numbered similarly.

[0016] Figure 1 This is a schematic diagram illustrating an application scenario of a signal switching circuit provided in an embodiment of this application.

[0017] Figure 2 This is a circuit block diagram of a signal switching circuit in one embodiment of this application.

[0018] Figure 3 This is a circuit diagram of a signal switching circuit provided in an embodiment of this application.

[0019] Figure 4 This is a schematic diagram of a signal switching fixture provided in an embodiment of this application in a first scenario.

[0020] Figure 5 This is a schematic diagram of a signal switching fixture provided in an embodiment of this application in a second scenario.

[0021] Figure 6 This is a schematic diagram of a circuit board in one embodiment of this application.

[0022] Explanation of main component symbols

[0023] Signal switching circuit 10

[0024] Input terminals 11, 11_1, 11_2, 11_3

[0025] Output terminal 12

[0026] Switching unit 13

[0027] Normally closed Nc

[0028] First normally closed contact Nc1

[0029] Second normally closed contact Nc2

[0030] Common terminal COM

[0031] First common contact Com1

[0032] Second common contact Com2

[0033] Normally Open No

[0034] First normally open contact No.1

[0035] Second normally open contact No.2

[0036] Control terminal Ctr

[0037] First connection end Co1

[0038] Second connection end Co2

[0039] Switching transistor 131

[0040] First current-limiting resistor R1

[0041] Second current-limiting resistor R2

[0042] Diode D

[0043] Power Supply 14

[0044] Connection port 15

[0045] Oscilloscope 20

[0046] Signal input source 30

[0047] Signal switching fixture 100

[0048] Controller 101

[0049] Circuit board 102

[0050] First side 1021

[0051] Second side 1022

[0052] Third side 1023

[0053] Support frame 103

[0054] Frame 104

[0055] Grooving 105

[0056] Door frame 106

[0057] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0059] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have an intervening component. When a component is considered to be "placed" on another component, it can be directly placed on the other component or may also have an intervening component. The terms "top," "bottom," "upper," "lower," "left," "right," "front," "back," and similar expressions used in this article are for illustrative purposes only.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0061] Some embodiments will now be described with reference to the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0062] Oscilloscopes can be used to observe the waveform curves of various signals as their amplitude changes over time, and can also be used to test various electrical quantities, such as voltage, current, frequency, phase difference, modulation amplitude, etc. However, existing general-purpose oscilloscopes have a limited number of channels, which means that when measuring a large number of signals under test, multiple plugging and unplugging are required, resulting in low testing efficiency.

[0063] In view of this, this application provides a signal switching circuit that can simplify manual operation, thereby improving testing efficiency and reducing testing costs.

[0064] Please see Figure 1 , Figure 1This is a circuit block diagram of a signal switching circuit 10 provided in one embodiment of this application. The signal switching circuit 10 is connected between an oscilloscope 20 and N signal input sources 30 (N is a positive integer, and N is greater than or equal to 1). The signal switching circuit 10 is used to acquire at least one input signal from the N signal input sources 30 and output it to the oscilloscope 20 for measurement by the oscilloscope 20. This application does not limit the type of signal input source 30; the signal input source 30 can be any port or circuit used to output electrical signals.

[0065] Please continue reading. Figure 2 , Figure 2 This is a circuit block diagram of a signal switching circuit 10 provided in an embodiment of this application. The signal switching circuit 10 includes N input terminals 11, one output terminal 12, and N-1 switching units 13.

[0066] Among them, the N input terminals 11 are connected one-to-one with the N signal input sources 30 to receive the corresponding input signals from the N signal input sources 30 respectively.

[0067] Output terminal 12 is used to connect to the channel of oscilloscope 20.

[0068] Each switching unit 13 includes a normally closed terminal Nc, a common terminal Com, a normally open terminal No, and a control terminal Ctr. N-1 common terminals Com are connected one-to-one with N-1 input terminals 11. The normally open terminal No of each switching unit 13 is sequentially connected to the common terminal Com of the adjacent switching unit 13 to form a signal path. One end of the signal path, the common terminal Com, is also connected to the output terminal 12. The other end of the signal path, the normally open terminal 133, is connected to the Nth input terminal 11. The control terminal Ctr receives control signals. When the received control signal is a first-level signal, the normally closed terminal Nc is connected to the common terminal Com, and the normally open terminal No is disconnected from the common terminal Com. When the control signal received by the control terminal Ctr is a second-level signal, the normally closed terminal Nc is disconnected from the common terminal Com, and the normally open terminal No is connected to the common terminal Com. The signal switching circuit 10 obtains a signal from the signal input source 30 from the N input terminals 11 according to the control signal received by each control terminal Ctr and outputs it to the oscilloscope 20 through the output terminal 12.

[0069] In this application, the first level signal is either a low-level signal or a high-level signal, and the second level signal is either a low-level signal or a high-level signal. In this example, the first level signal is described as low and the second level signal as high. The low-level signal can be, for example, a voltage of 0, and the high-level signal can be, for example, a voltage of 3.3V. This application does not limit the specific voltage values ​​of the low-level and high-level signals; it only requires that the voltage of the high-level signal is greater than the voltage of the low-level signal.

[0070] Understandably, the signal switching circuit 10 operates on the following principle:

[0071] by Figure 2 The illustrated circuit block diagram illustrates that when all control signals received by switching units 13 are at the first level, the input signal received at input terminal 11 of the first switching unit 13 can be directly output to the oscilloscope 20 through the common terminal Com and output terminal 12, and the common terminal Com is disconnected from the normally open terminal No. Since the normally open terminal No in the first switching unit 13 is connected to the common terminal Com in the second switching unit 13, the common terminal Com in the first switching unit 13 is disconnected from the common terminal Com in the second switching unit 13. Therefore, the input signal at input terminal 11 connected to the common terminal Com in the second switching unit 13 cannot be output to output terminal 12 through the common terminal Com in the first switching unit 13. Similarly, all other switching units 13 in the signal switching circuit 10, except for the first switching unit 13, cannot be connected to the common terminal Com of the first switching unit 13 for the same reason. Thus, when all the control signals received by the switching units 13 are first level signals, the first switching unit 13 in the signal switching circuit 10 obtains the input signal of the corresponding connected signal input source 30 and outputs it to the oscilloscope 20.

[0072] When only the control terminal Ctr of the second switching unit 13 receives the second level signal, and the control terminals Ctr of all other switching units 13 receive the first level signal, according to the above description, the input signal received by the input terminal 11 in the first switching unit 13 can be directly output to the oscilloscope 20 through the common terminal Com and the output terminal 12. Simultaneously, although the control terminal Ctr of the second switching unit 13 receives the second level signal, causing the common terminal Com in the second switching unit 13 to conduct with the normally open terminal No, since the common terminal Com in the first switching unit 13 is disconnected from the normally open terminal No, the input signal of the input terminal 11 connected to the common terminal Com in the second switching unit 13 cannot be output to the output terminal 12 through the common terminal Com in the first switching unit 13. Thus, when only the control terminal Ctr of the second switching unit 13 receives the second level signal, and the control terminals Ctr of all other switching units 13 receive the first level signal, the first switching unit 13 in the signal switching circuit 10 acquires the input signal of the corresponding connected signal input source 30 and outputs it to the oscilloscope 20.

[0073] Similarly, based on the control signal received by the control terminal Ctr of each switching unit 13, the signal switching circuit 10 can acquire a signal from a signal input source 30 and output it to the oscilloscope 20.

[0074] Understandably, the signal switching circuit 10 provided in this application, by setting an output terminal 12, N input terminals 11, and N-1 switching units 13, and by controlling the N-1 switching units 13, allows the N-1 switching units 13 to obtain one input signal from the N signal input sources 30 connected to the N input terminals 11, and output it to the oscilloscope 20 through the output terminal 12. Thus, the signal switching circuit 10 provided in this application not only reuses the signal input channels of the oscilloscope 20, but also reduces the number of circuit plugging and unplugging operations when testing multiple signal input sources 30, thereby improving testing efficiency.

[0075] Please continue reading. Figure 3 , Figure 3 This is a detailed circuit diagram of the signal switching circuit 10 provided in one embodiment of this application. It can be understood that... Figure 3 The circuit diagram shown is a schematic diagram of the signal switching circuit 10 including two switching units 13. This application uses... Figure 3 Taking the circuit diagram shown as an example, the specific circuit diagram of the signal switching circuit 10 provided in this application will be further explained.

[0076] In some embodiments, the normally open terminal No includes a first normally open contact No1 and a second normally open contact No2. The common terminal Com includes a first common contact Com1 and a second common contact Com2. The normally closed terminal Nc includes a first normally closed contact Nc1 and a second normally closed contact Nc2.

[0077] The first common contact Com1, located at one end of the signal path, is connected to the first end of the output terminal 12, and the second common contact Com2, located at one end of the signal path, is also connected to the second end of the output terminal 12.

[0078] The first normally open contact No1 of the switching unit 13 located at the other end of the signal path is connected to the first end of the corresponding input terminal 11, and the second normally open contact No2 of the switching unit 13 located at the other end of the signal path is connected to the second end of the corresponding input terminal 11. The first normally open contact No1 of each of the remaining switching units 13 is connected to the first common contact Com1 of the adjacent switching unit 13, and the second normally open contact No2 of each of the remaining switching units 13 is connected to the second common contact Com2 of the adjacent switching unit 13.

[0079] The first normally closed contact Nc1 in each switching unit 13 is connected to the first common contact Com1. The first normally closed contact Nc1 in each switching unit 13 is also connected to the first end of the corresponding input terminal 11. The second normally closed contact Nc2 in each switching unit 13 is connected to the second common contact Com2. The second normally closed contact Nc2 in each switching unit 13 is also connected to the second end of the corresponding input terminal 11.

[0080] In some embodiments, the signal switching circuit 10 further includes a power supply 14. Each switching unit 13 further includes a switching transistor 131, a first connection terminal Co1, and a second connection terminal Co2.

[0081] In each switching unit 13, the first connection terminal Co1 is connected to the first terminal of the switching transistor 131, the second connection terminal Co2 is connected to the first connection terminal Co1, the second connection terminal Co2 is connected to the positive terminal of the power supply 14, the negative terminal of the power supply 14 is connected to the second terminal of the switching transistor 131, and the third terminal of the switching transistor 131 is connected to the control terminal Ctr.

[0082] In this embodiment, the switching transistor 131 can be an NPN transistor, with its first terminal being the collector, its second terminal being the emitter, and its third terminal being the base. In other embodiments, the switching transistor 131 can also be replaced by a MOSFET, an insulated-gate bipolar transistor (IGBT), a relay, or other circuits capable of performing switching functions; this application does not impose any limitations on this.

[0083] Understandably, when the control terminal Ctr receives the first level signal, the switch transistor 131 is turned off. At this time, the first connection terminal Co1 in the corresponding switching unit 13 is disconnected from the first normally closed contact Nc1, and the first normally closed contact Nc1 is connected to the first common contact Com1; at the same time, the second connection terminal Co2 is disconnected from the second normally closed contact Nc2, and the second normally closed contact Nc2 is connected to the second common contact Com2.

[0084] When the control terminal Ctr receives the second level signal, the switch 131 is turned on, causing the first connection terminal Co1 to be connected to the first normally closed contact Nc1, and the first normally closed contact Nc1 to be disconnected from the first common contact Com1; at the same time, the second connection terminal Co2 is connected to the second normally closed contact Nc2, and the second normally closed contact Nc2 is disconnected from the second common contact Com2.

[0085] In some embodiments, each switching unit 13 further includes a first current-limiting resistor R1, a second current-limiting resistor R2, and a diode D. In each switching unit 13, the second connection terminal Co2 is connected to the first connection terminal Co1 through the first current-limiting resistor R1. The anode of the diode D is connected between the first terminal of the switching transistor 131 and the first connection terminal Co1, the cathode of the diode D is connected to the second connection terminal Co2, and the third terminal of the switching transistor 131 is connected to the control terminal Ctr through the second current-limiting resistor R2.

[0086] Understandably, by setting the first current-limiting resistor R1 and the second current-limiting resistor R2, the risk of overcurrent can be reduced; by setting the diode D, current from the second terminal of the switching transistor 131 can be prevented from flowing to the first terminal. Thus, the first current-limiting resistor R1, the second current-limiting resistor R2, and the diode D can reduce the safety risks of the signal switching circuit 10.

[0087] In some embodiments, each switching unit 13 further includes a connection port 15. The first end of the connection port 15 is connected between the first normally closed contact Nc1 and the first end of the corresponding connected input terminal 11, and the second end of the connection port 15 is connected between the second normally closed contact Nc2 and the second end of the corresponding connected input terminal 11.

[0088] Thus, by providing the connection port 15, users can easily add electronic components to the signal switching circuit 10, thereby improving the circuit flexibility of the signal switching circuit 10. For example, in some embodiments, a capacitor can be connected through the connection port 15 to filter out interference signals in the signal switching circuit 10.

[0089] In some embodiments, input terminal 11 and output terminal 12 can be BNC terminals, and connection port 15 can be a 2P terminal block. In other embodiments, input terminal 11, output terminal 12, and connection port 15 can also be other types of ports. This application does not limit the specific port types of input terminal 11, output terminal 12, and connection port 15.

[0090] Understandably, in some embodiments, control can be performed according to the following table. Figure 3 The signal switching circuit 10 shown acquires the signal from the signal input source 30 connected to an input terminal 11 and outputs it to the oscilloscope 20.

[0091] Figure 3 The control diagram of the signal switching circuit 10 shown is as follows.

[0092] Ctr1 Ctr2 11_1 11_2 11_3 First level signal First level signal √ First level signal Second level signal √ Second level signal First level signal √ Second level signal Second level signal √

[0093] As shown in the table above, the signal switching circuit 10 can obtain the signal from the signal input source 30 connected to the input terminal 11 and output it to the oscilloscope 20 according to the combination of control signals received by the two switching units 13.

[0094] Please refer to the following: Figure 4 and Figure 5 An embodiment of this application also provides a signal switching fixture 100. The signal switching fixture 100 includes a controller 101 and at least one signal switching circuit 10. The controller 101 is electrically connected to the control terminal Ctr of each switching unit 13 and is used to output control signals to the control terminal Ctr of each switching unit 13.

[0095] The controller 101 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or processor 201, or any conventional processor. For example, the controller 101 can be an Arduino; this application does not limit this.

[0096] In some embodiments, the signal switching fixture 100 may include eight signal switching circuits 10, and each signal switching circuit 10 is provided with three input terminals 11 to be connected to three signal input sources 30 respectively. Thus, the signal switching fixture 100 can be connected to 24 signal input sources 30. The signal switching fixture 100 controls the eight switching circuits through a controller 101, and can acquire any input signal from the 24 signal input sources 30 to output to the oscilloscope 20. This significantly improves testing efficiency and reduces testing costs.

[0097] Furthermore, the controller 101 can be pre-programmed with a control program to automatically select the corresponding signal input source 30 to acquire the input signal when the operator inputs a corresponding command, and output it to the oscilloscope 20 through the output terminal 12. This simplifies the relevant operations for the operator.

[0098] The signal switching fixture 100 includes a plurality of circuit boards 102, each circuit board 102 for carrying at least one signal switching circuit 10. For example, see [link to relevant documentation]. Figure 6 In some embodiments, the circuit board 102 may be provided with two signal switching circuits 10.

[0099] The circuit board 102 includes a first side 1021, and a second side 1022 and a third side 1023 adjacent to the first side 1021, respectively. The output terminals 12 of both signal switching circuits 10 are located on the first side 1201, all input terminals 11 of one signal switching circuit 10 are located on the second side 1202, and all input terminals 11 of the other signal switching circuit 10 are located on the third side 1203.

[0100] Please refer to it again. Figure 4 and Figure 5In some embodiments, the signal switching fixture 100 further includes a support frame 103. The support frame 103 is disposed between two circuit boards 102, so that several circuit boards 102 are stacked and spaced apart. Specifically, one end of the support frame 103 is connected to the side of the circuit board 102 where the input terminal 11 and the output terminal 12 are provided, and the other end of the support frame 103 is connected to the side of another circuit board 102 where the input terminal 11 and the output terminal 12 are not provided. Moreover, four support frames 103 can be respectively provided at the four corners of the circuit board 102, that is, the two circuit boards 102 are connected through four support frames 103. In this way, multiple circuit boards 102 can be disposed in the signal switching fixture 100, thereby providing multiple signal switching circuits 10, so as to realize the connection between the signal switching fixture 100 and more signal input sources 30.

[0101] Please refer to it again. Figure 4 and Figure 5 In some embodiments, the signal switching fixture 100 further includes a frame 104. The frame 104 is used to house at least one signal switching circuit 10 and a controller 101. The controller 101 may be disposed on one side wall inside the frame 104, and the space formed by the frame 104 is used to house a plurality of circuit boards 102. In this way, the drop and shock resistance of the signal switching fixture 100 can be increased.

[0102] The frame 104 has a plurality of slots 105, and the plurality of slots 105 are provided corresponding to the input terminal 11 and the output terminal 12 of at least one signal switching circuit 10. In this way, it is convenient for the operator to make electrical connections between the signal switching fixture 100 and the oscilloscope 20 and the signal input source 30.

[0103] In some embodiments, the frame 104 is also provided with an openable door frame 106. This facilitates the maintenance of the signal switching circuit 10 inside the signal switching fixture 100 by the staff.

[0104] In summary, the signal switching fixture 100 provided in this application, by setting up a controller 101 and at least one signal switching circuit 10, further expands the number of connected signal input sources 30 and simplifies the testing operations of the staff, thereby improving testing efficiency.

[0105] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this application, and are not intended to be limiting.

[0106] This application is not limited to the specific embodiments described above. Those skilled in the art will readily understand that many alternative solutions exist for the test fixture without departing from the principles and scope of this application. The scope of protection of this application is determined by the claims.

Claims

1. A signal switching circuit, characterized in that, The signal switching circuit is connected between the oscilloscope and N signal input sources. The signal switching circuit includes: The N input terminals are connected one-to-one with the N signal input sources, respectively. The output terminal is used to connect to the channel of the oscilloscope; There are N-1 switching units, each of which includes a normally closed terminal, a common terminal, a normally open terminal, and a control terminal. The N-1 common terminals are connected one-to-one with the N-1 input terminals. The normally open terminal of each switching unit is sequentially connected to the common terminal of the adjacent switching unit to form a signal path. The common terminal at one end of the signal path is connected to the output terminal, and the normally open terminal at the other end of the signal path is connected to the Nth input terminal. The control terminal is used to receive a control signal. When the control signal is a first level signal, the normally closed terminal is connected to the common terminal, and the normally open terminal is disconnected from the common terminal. When the control signal is a second level signal, the normally closed terminal is disconnected from the common terminal, and the normally open terminal is connected to the common terminal. The signal switching circuit obtains a signal from a signal input source from the N input terminals according to the control signal received by each control terminal and outputs it to the oscilloscope through the output terminal.

2. The signal switching circuit according to claim 1, characterized in that, The normally open terminal includes a first normally open contact and a second normally open contact; the common terminal includes a first common contact and a second common contact; and the normally closed terminal includes a first normally closed contact and a second normally closed contact. The first common contact located at one end of the signal path is connected to the first end of the output terminal, and the second common contact located at one end of the signal path is also connected to the second end of the output terminal; The first normally open contact of the switching unit located at the other end of the signal path is connected to the first end of the corresponding input terminal, and the second normally open contact of the switching unit located at the other end of the signal path is connected to the second end of the corresponding input terminal. The first normally open contact of each of the remaining switching units is connected to the first common contact of the adjacent switching unit, and the second normally open contact of each of the remaining switching units is connected to the second common contact of the adjacent switching unit. The first normally closed contact in each switching unit is connected to the first common contact, and the first normally closed contact in each switching unit is also connected to the first end of the corresponding input terminal. The second normally closed contact in each switching unit is connected to the second common contact, and the second normally closed contact in each switching unit is also connected to the second end of the corresponding input terminal.

3. The signal switching circuit according to claim 2, characterized in that, The signal switching circuit further includes a power supply, and each switching unit further includes a switching transistor, a first connection terminal, and a second connection terminal, wherein, in each switching unit, The first connection terminal is connected to the first terminal of the switching transistor, the second connection terminal is connected to the first connection terminal, the second connection terminal is connected to the positive terminal of the power supply, the negative terminal of the power supply is connected to the second terminal of the switching transistor, and the third terminal of the switching transistor is connected to the control terminal.

4. The signal switching circuit according to claim 3, characterized in that, Each of the switching units further includes a first current-limiting resistor, a second current-limiting resistor, and a diode. In each of the switching units, the second connection terminal is connected to the first connection terminal through the first current-limiting resistor, the anode of the diode is connected between the first terminal of the switching transistor and the first connection terminal, the cathode of the diode is connected to the second connection terminal, and the third terminal of the switching transistor is connected to the control terminal through the second current-limiting resistor.

5. The signal switching circuit according to claim 2, characterized in that, Each of the switching units further includes a connection port, a first end of which is connected between the first normally closed contact and the first end of the corresponding connected input terminal, and a second end of which is connected between the second normally closed contact and the second end of the corresponding connected input terminal.

6. A signal switching fixture, characterized in that, The signal switching fixture further includes a controller and at least one signal switching circuit as described in any one of claims 1 to 5, wherein the controller is electrically connected to the control terminal of each of the switching units and is used to output a control signal to each of the control terminals.

7. The signal switching fixture according to claim 6, characterized in that, The signal switching fixture includes several circuit boards, each of which carries at least one of the signal switching circuits.

8. The signal switching fixture according to claim 7, characterized in that, The circuit board includes a first side, and a second side and a third side adjacent to the first side respectively. The output terminals of the two signal switching circuits are disposed on the first side, all input terminals of one signal switching circuit are disposed on the second side, and all input terminals of the other signal switching circuit are disposed on the third side.

9. The signal switching fixture according to claim 7, characterized in that, The signal switching fixture also includes a support frame, which is disposed between the two circuit boards so that the circuit boards are stacked and spaced apart.

10. The signal switching fixture according to claim 6, characterized in that, The signal switching fixture further includes a frame for accommodating at least one of the signal switching circuits and the controller. The frame has a plurality of slots, and the plurality of slots correspond to the input and output terminals of at least one of the signal switching circuits.

Images