CN202759445U - Electric power line communication channel test adapter box - Google Patents

Abstract

The utility model discloses a power line communication channel test adaptation box, comprising: a three-phase power supply input terminal, a coupler connected to each phase of the three-phase power supply input terminal, the three-phase power supply input terminal and the coupler The air switch connected between, the first rotary switch connected with the coupler to select the phase, the attenuator connected with the first rotary switch, the signal output terminal connected with the attenuator, and the three-phase A socket connected to any phase of the power input end, and an indicator light connected to each phase of the three-phase power input end. The utility model can output a power signal with an appropriate frequency and an amplitude suitable for the terminal equipment, has a high safety factor, greatly protects the safety of the person and the test equipment, and is easy to operate and easy to carry, which provides convenience for the test, thereby increasing the test capacity. s efficiency.

Description

A power line communication channel test adaptation box

technical field

The utility model relates to the field of power line communication systems, in particular to a power line communication channel test adaptation box.

Background technique

Power Line Communication (PLC) technology is referred to as PLC, which refers to a communication method that uses power lines to transmit data. To achieve reliable communication over power lines, it is necessary to fully understand the characteristics of power line channels. Although foreign companies have relatively mature chips, these chips are designed based on the characteristics of foreign power line channels, and many problems arise when they are used in China. Therefore, it is very important to study the domestic PLC communication site to design a communication system that meets the requirements of the domestic power line communication channel.

Domestic research on power line communication basically focuses on application-oriented development using existing foreign chips, and relatively few people engage in basic theoretical research. When designing the modulation, mediation and encoding and decoding algorithms of power line communication, it is necessary to understand the characteristics of domestic power line channels in detail, but there are too few data that can be used for reference. In order to better study carrier communication and ultimately guide chip design, it is necessary to go to On-site channel parameter testing to obtain real first-hand on-site data. Through the crosstalk test, attenuation test, noise test, impedance test, topology test, voltage test and current test of typical on-site PLC communication channels, key data such as factors affecting PLC communication performance and degree of influence are obtained to provide data support for carrier simulation. Provide guidance for carrier chip design.

At present, there are two main methods for testing the channel characteristics of low-voltage power lines: the first method is to use a spectrum analyzer to directly obtain the spectrum characteristics of the power line signal; the second method is to use a digital storage oscilloscope to first store the time domain information of the signal After that, it is sent to the computer, and then the spectrum estimation is performed to obtain the spectrum characteristics of the signal. Either way, the signal on the power line needs to be safely introduced to a spectrum analyzer or digital storage oscilloscope. However, due to the complex power line environment, various signals, and different amplitudes, if the test instrument is directly connected to the power grid for testing, the instrument may be burned. At the same time, some misoperations may occur during on-site testing, which may cause tripping of power protection devices such as circuit breakers in the power grid, which will cause great losses.

Utility model content

The purpose of the utility model is to propose a power line communication channel test adaptation box, which can output power signals with appropriate frequency and amplitude suitable for terminal equipment.

For this purpose, the utility model adopts the following technical solutions:

A power line communication channel test adaptation box, comprising: a three-phase power input end, a coupler connected to each phase of the three-phase power input end, and an air connection between the three-phase power input end and the coupler A switch, a first rotary switch for phase selection connected to the coupler, an attenuator connected to the first rotary switch, a signal output terminal connected to the attenuator, and any one of the three-phase power input terminals Connected plug strips, and indicator lights connected to each phase of the three-phase power input end.

As a preference of the above technical solution, the attenuator is at least two attenuators connected in series.

As a preference of the above technical solution, the adapter box further includes a second rotary switch for selecting the attenuation range, which is connected between the attenuator and the output terminal.

As a preference of the above technical solution, the socket is an isolated socket.

As a preference of the above technical solution, the isolated plug-in strip includes: an RL parallel filter circuit connected in series with the input terminals of the power supply of the plug-in strips, and an RC series filter circuit connected in parallel between the input terminals of the power supply of the plug-in strips.

As a preference of the above technical solution, the adapter box further includes a button switch connected between the attenuator and the signal output end.

Adopting the technical solution of the utility model, due to the addition of a coupler and an attenuator, it can output a power signal with an appropriate frequency and an amplitude suitable for the terminal equipment, with a high safety factor, and can effectively protect the spectrum analyzer or digital signal while facilitating signal access. Storage oscilloscopes and other equipment greatly protect the safety of personal and test equipment, and are easy to operate and carry, which provides convenience for testing and thus increases the efficiency of testing.

Description of drawings

Fig. 1 is a structural block diagram of an embodiment of the power line communication channel test adaptation box proposed by the utility model.

Fig. 2 is a circuit schematic diagram of an embodiment of the power line communication channel test adaptation box proposed by the utility model.

Fig. 3 is a schematic circuit diagram of the plug-in isolation circuit of the embodiment of the power line communication channel test adaptation box proposed by the utility model.

Fig. 4 is a schematic view of an embodiment of the power line communication channel test adaptation box proposed by the present invention.

Detailed ways

The technical scheme of the utility model will be further described below in conjunction with the accompanying drawings and through specific embodiments.

Fig. 1 is a structural block diagram of an embodiment of the power line communication channel test adaptation box proposed by the utility model, and Fig. 2 is a schematic circuit diagram of a specific embodiment of the power line communication channel test adaptation box proposed by the utility model, as shown in the figure Show:

J1 is a three-phase power input terminal, which is a plug in this embodiment, and is used for the access of the three-phase power supply; K1 connected with the power input terminal is an air switch for controlling the on-off of the three-phase power supply; J4, J5, and J6 connected to each phase of the input end are carrier signal couplers, and dual outputs with 20dB attenuation and 0dB attenuation can be selected, so the coupler can easily switch between attenuation or non-attenuation when coupling the carrier signal , so it can better protect the instrument; J2 is a 3-speed rotary switch for three-phase power phase selection; P3, P4, P5, and P6 connected after the rotary switch J2 are series-connected cable core attenuators, and their main purpose is to connect to the The input terminal of the test equipment attenuates the high-power signal to protect the test equipment from being burned. It can be connected in series in multiple stages to increase the attenuation multiple; J3 is a 5-speed knob switch for the selection of the signal attenuation range; it can be connected with any of the three-phase power input terminals One or more sockets P1 and P2 connected to each other are used to provide power for test equipment, etc.; and indicator lights L1, L2 and L3 connected to each phase of the three-phase power input end, which can be 220V indicator lights , used to judge the on-off of the line; S1 is the button switch, which controls the on-off of the signal output; OUT is the signal output terminal, connected to the test equipment.

Wherein, the plug-in strip in the above-mentioned embodiment may be an isolated plug-in strip, and the isolated plug-in strip is a transformation of a common plug-in strip. As shown in FIG. 3 , the isolation circuit in the isolated plug-in strip includes: A series RL parallel filter circuit (R1L1, R2L2), and an RC series filter circuit (R3C1C2) connected in parallel between the input terminals IN of the plug-in power supply.

The isolation strip can be used to supply power to external devices. By adding an isolation circuit to the ordinary strip, it can be isolated from the carrier power line and provide a clean power supply for the test instrument, so that the instrument has no interference with the power signal and ensures the safety of the test equipment.

As shown in Figure 4, the power line communication channel test adapter box proposed by the utility model is connected between the power network and the test equipment, the power line signal passes through the test adapter box to the test equipment, and the signal on the power line passes through the coupler. After the out-of-band noise is filtered, the signal in the power carrier meter reading range of 10kHz-500kHz is output, and then the attenuation amplitude is attenuated after passing through the attenuator to the range of the test equipment at the OUT terminal.

The following describes the operation method of the power line communication channel test adaptation box proposed by the utility model:

When the air switch K1 is off, connect to three-phase power or single-phase power;

Turn on the air switch K1 and check whether the indicator light is on. If it is not on, turn off the air switch K1 and check whether the terminals are in good contact;

Turn the attenuation selection knob J3 to the maximum value, and connect to the test instrument through the OUT signal output terminal;

By rotating the phase selection knob J2 and adjusting the attenuation selection knob J3, press the S1 button to display the signal on the screen of the instrument for testing. If the signal amplitude exceeds the test range of the instrument, you can immediately release the S1 button or adjust the attenuation value to make the signal in Within the measuring range, avoid burning the instrument;

After the test is completed, the attenuation selection knob J3 is turned to the maximum value, and the power connection line can be disassembled only after the air switch is disconnected.

One or more embodiments of the present application have the following advantages:

1. Provide a filtering and attenuation method for power line signals. Couplers and attenuators are added to the new model, which can output power signals with appropriate frequency and amplitude suitable for terminal equipment.

2. To modify the common plug-in strip, by adding an isolation circuit, such as in this case, by isolating from the carrier power line, it can provide a clean power supply for the test instrument, which can effectively isolate the interference of the test instrument to the power line environment.

3. High safety factor, which greatly protects the safety of personal and test equipment;

4. The device is easy to operate and easy to carry, which provides convenience for the test and thus increases the efficiency of the test.

The above is only a preferred embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, any person familiar with the technology can easily think of it within the technical scope disclosed in the utility model Changes or replacements should fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (7)

1. A power line communication channel test adaptation box is characterized in that, comprising: a three-phase power input terminal, a coupler connected to each phase of the three-phase power input terminal, the three-phase power input terminal and the coupling The air switch connected between the couplers, the first rotary switch connected to the coupler to select the phase, the attenuator connected to the first rotary switch, the signal output terminal connected to the attenuator, and the three A plug-in strip connected to any phase of the three-phase power input end, and an indicator light connected to each phase of the three-phase power input end. 2 . The power line communication channel test adaptation box according to claim 1 , wherein the attenuators are at least two attenuators connected in series. 3 . 3. The power line communication channel test adaptation box according to claim 2, characterized in that, the adaptation box further comprises a second rotary switch for selecting the attenuation range, which is connected between the attenuator and the output terminal. 4. The power line communication channel test adaptation box according to any one of claims 1-3, wherein the plug-in strip is an isolated strip. 5. The power line communication channel test adaptation box according to claim 4, wherein the isolated plug-in strip comprises: a resistance-inductance parallel filter circuit connected in series with the power supply input end of the plug-in strip, and connected in parallel to the power input end of the plug-in strip Between the resistor and capacitor in series filter circuit. 6. The power line communication channel test adaptation box according to any one of claims 1-3, wherein the adaptation box further comprises a button switch connected between the attenuator and the signal output terminal. 7. The power line communication channel test adaptation box according to claim 4, characterized in that, the adaptation box further comprises a button switch connected between the attenuator and the signal output terminal.

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