Electrical circuit quality detection device

Abstract

A circuit quality detection device for an electric circuit comprises two electric connectors, a load resistor, a switch element, a display module and a control module, wherein the two electric connectors are inserted into a socket and connected to two power lines; one end of the load resistor is connected to the electric connector, and the other end is connected to a first end of the switch element; a second end of the switch element is connected to another electric connector; the control module controls the switch element to be cut off in a detection mode, detects a peak voltage in a voltage waveform and records it as a maximum open circuit voltage, and then controls the switch element to be turned on, detects a peak voltage in the voltage waveform and records it as a load voltage and calculates a load current; a circuit resistance value is calculated according to the maximum open circuit voltage, the load voltage and the load current, and a corresponding message is displayed through the display module.

Description

Technical Field

[0001] The present invention relates to aging detection of power lines, and in particular to a circuit quality detection device for electric circuits. Background Art

[0002] The general power distribution is to connect one end of two power lines to an AC power source, and the other end of the two power lines to a socket, and the power of the AC power source is transmitted to the socket through the two power lines. When the user plugs the plug of the electrical device into the socket, the power of the AC power source can be supplied to the electrical device, allowing the electrical device to operate.

[0003] Although power lines can conduct electricity, they are not ideal conductors and still have line resistance. Therefore, when the current of the AC power source flows through the power lines, heat will be generated due to the line resistance. The higher the resistance of the power lines or the higher the current flowing through the power lines, the more heat will be generated by the current. Therefore, after a certain number of years of use, the power lines will be repeatedly heated up and cooled down, which will cause the power lines to age and increase the line resistance. When the line resistance increases, more heat will be generated, which will accelerate the aging of the power lines.

[0004] However, ordinary users cannot know the aging status of power lines and can only judge whether to replace power lines based on the time when the power lines were installed and the normal power usage. In this way, if the power lines have aged to the point of being unusable before replacement, the high temperature generated by the power lines may ignite surrounding items and cause a fire.

[0005] The resistance of a good power line is usually below 1 ohm. Even an old and unusable power line has a resistance of only a few ohms. General electric meters cannot accurately measure this. The impedance analyzers sold on the market for measuring low resistance are not only expensive, but also bulky and inconvenient to carry. They are also not easy to use for impedance testing of power lines at home. Therefore, how to effectively and conveniently test the line quality of the power circuit at home is a problem that needs to be solved urgently. Summary of the invention

[0006] In view of this, an object of the present invention is to provide an electric circuit line quality detection device, which can detect the quality of the power line and is easy to use and carry.

[0007] In order to achieve the above-mentioned purpose, the present invention provides an electric circuit line quality detection device, which is used to connect a socket, and the socket is connected to two power lines, and the two power lines are connected to an AC power source. The electric circuit line quality detection device comprises: two electrical connectors, a load resistor, a switch element, a display module and a control module, wherein the two electrical connectors are connected to the socket to receive the AC power of the AC power source through the two power lines; one end of the load resistor is electrically connected to one of the two electrical connectors; the switch element has a first end and a second end, the first end is electrically connected to the other end of the load resistor, and the second end is electrically connected to the other of the two electrical connectors. One; the control module is electrically connected to the two ends of the load resistor, the switch element and the display module to perform a detection mode. In the detection mode, the control module controls the switch element to be cut off, detects the peak voltage in a half-wave in a voltage waveform of the alternating current and records it as a maximum open-circuit voltage, and then controls the switch element to be turned on, detects the peak voltage in the voltage waveform and records it as a load voltage, and calculates a load current flowing through the load resistor; the control module calculates a line resistance value of the socket and the two power lines based on the maximum open-circuit voltage, the load voltage and the load current, and displays a message corresponding to the line resistance value through the display module.

[0008] The effect of the present invention is that the electrical circuit line quality detection device can accurately measure the line resistance of the overall circuit of the socket and the power line, and provide corresponding information on the display module, so that the user can know the current line quality of the overall circuit and further evaluate whether the socket or the power line needs to be replaced. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 FIG. 1 is a schematic diagram of an electrical circuit quality detection device according to a first preferred embodiment of the present invention.

[0010] Figure 2 4 is a voltage waveform diagram of the above preferred embodiment.

[0011] Figure 3 FIG. 1 is a schematic diagram of an electrical circuit quality detection device according to a second preferred embodiment of the present invention.

[0012] Figure 4 FIG. 4 is a schematic diagram of an electrical circuit quality detection device according to a third preferred embodiment of the present invention. DETAILED DESCRIPTION

[0013] In order to more clearly illustrate the present invention, preferred embodiments are described in detail below with reference to the accompanying drawings. Figure 12 , an electric circuit line quality detection device 1 according to a first preferred embodiment of the present invention is shown, comprising a housing 10 , two electrical connectors 12 disposed in the housing, a load resistor 14 , a switch element 16 , a display module 18 and a control module 20 .

[0014] The two electrical connectors 12 are used to be inserted into a socket 100 , and the socket 100 is electrically connected to two power lines 200 , and the two power lines 200 are connected to an AC power source 300 , and the voltage of the AC power of the AC power source 300 can be 100-240V.

[0015] The load resistor 14 has two ends, one end of which is electrically connected to one of the two electrical connectors 12. The load resistor 14 is a power resistor, and its resistance value is 10 ohms for example, and its resistance value is preferably not more than 10 ohms.

[0016] The switch element 16 is a power transistor in this embodiment, which may be a MOSFET or a BJT. In one embodiment, the switch element 16 may also be a relay. The switch element 16 has a first end 162 and a second end 164. The switch element 16 can be controlled to turn off or on the first end 162 and the second end 164. The first end 162 is electrically connected to the other end of the load resistor 14, and the second end 164 is electrically connected to the other of the two electrical connectors 12.

[0017] In this embodiment, the electrical circuit line quality detection device 1 further includes a rectifier module 22, which is a full-wave rectifier module and is electrically connected between the two electrical connectors 12 and the load resistor 14. The full-wave rectifier module can be, for example, a bridge rectifier. One end of the load resistor 14 is electrically connected to one of the two electrical connectors 12 through the rectifier module 22, and the second end 164 of the switch element 16 is electrically connected to the other of the two electrical connectors 12 through the rectifier module 22.

[0018] The display module 18 is used to display the detection status. In this embodiment, the display module 18 includes a plurality of LED elements. For example, eight LED elements are used. Each LED element has two light colors, such as red and green.

[0019] The control module 20 is electrically connected to the two ends of the load resistor 14, the switch element 16 and the display module 18. In more detail, the control module 20 is a microcontroller and has at least two analog-to-digital converters inside. In practice, the control module 20 can also be a structure in which the microcontroller and the analog-to-digital converter are separated. The control module 20 is electrically connected to the two ends of the load resistor 14 through two voltage divider circuits 24 and 26 respectively. The two voltage divider circuits 24 and 26 are used to step down the voltages at the two ends of the load resistor 14 (i.e., nodes N1 and N2) and input them to the two analog-to-digital converters in the control module 20. For example, if the voltage division ratio set by the two voltage divider circuits 24 and 26 is 100 to 1, and the above ratio will be written into the control module 20 in advance. Therefore, when the voltages received by the two analog-to-digital converters in the control module 20 are 1.1 volts and 0.01 volts, it means that the voltages on the nodes N1 and N2 are 110 volts and 1 volt at this time. Of course, in practice, the voltage division ratio of the two voltage division circuits 24 and 26 can be set according to different usage environments and is not limited to the above ratio. The control module 20 stores the resistance value of the load resistor 14. The power source of the control module 20 comes from a power supply module 28, and the power supply module 28 is electrically connected to the two electrical connectors 12 to convert the alternating current into the direct current required by the control module 20.

[0020] The control module 20 is used to perform a detection mode. The steps performed in the detection mode are as follows:

[0021] Step 1: The control module 20 controls the switch element 16 to be turned off, and detects a peak voltage in a voltage waveform and records it as a maximum open circuit voltage V OC (Reference Figure 2 ), in this embodiment, the control module 20 continuously obtains the change of the voltage waveform from the node N1, detects the frequency or period of the voltage waveform, and records the peak voltage in the voltage waveform as the maximum open circuit voltage V OC Since the voltage division ratio of the voltage division circuit 24 is known, the control module 20 can calculate the maximum open circuit voltage V according to the voltage input to the analog-to-digital converter. OC .

[0022] Step 2: The control module 20 controls the switch element 16 to conduct, and detects the peak voltage in the voltage waveform and records it as a load voltage V L (Reference Figure 2 ), the load voltage V L is less than the maximum open circuit voltage V OCIn this embodiment, the control module 20 controls the switch element 16 to conduct for a conduction time T according to the measured frequency or period. on , and detect the peak voltage in the voltage waveform during the conduction time and record it as the load voltage. When the switch element 16 is turned on, the control module 20 obtains the change of the voltage waveform from nodes N1 and N2 respectively. At the peak voltage in the voltage waveform, the voltage drop (i.e., the voltage difference) between nodes N1 and N2 is the load voltage V L Since the voltage division ratio of the voltage division circuit 26 is known, the control module 20 can calculate the load voltage V according to the voltage input to the analog-to-digital converter. L .

[0023] Preferably, the control module 20 controls the switch element 16 to be turned on in step 2 within a half-wave cycle after the peak voltage of the voltage waveform is detected in step 1, and the on-time T on It is preferred that the voltage does not exceed one half-wave cycle of the voltage waveform. In other words, when the maximum open circuit voltage V OC The load voltage V can be obtained at the peak voltage of the next half wave after L , thereby speeding up the detection speed. on The load resistor 14 can be prevented from overheating by not exceeding one half-wave cycle of the voltage waveform. The conduction can be set to be above 0.8 times the peak voltage of the voltage waveform.

[0024] Step 3: Since the resistance value of the load resistor 14 is known, the control module 20 can calculate a load current flowing through the load resistor 14, and the load current is equal to the load voltage V L divided by the resistance value of the load resistor 14. The control module 20 then determines the maximum open circuit voltage V OC , the load voltage V L The line resistance value of the socket 100 and the two power lines 200 is calculated based on the load current. The calculation formula of the line resistance value is as follows:

[0025] r = (V OC -V L ) / I L

[0026] Where r is the line resistance, V OC is the maximum open circuit voltage, V L is the load voltage, I L is the load current.

[0027] Step 4: The control module 20 displays a message corresponding to the line resistance value through the display module 18. In this embodiment, the control module 20 compares the line resistance value with a plurality of preset resistance value ranges to determine the resistance value range to which the line resistance value belongs, and displays the corresponding message on the display module 18 according to the resistance value range to which it belongs. For example, as shown in Table 1 below, the control module 20 controls the number and color of the LED components to be lit according to the number of segments to which the line resistance value belongs, and forms the message. The first and second segments represent abnormalities, the third to fifth segments represent normal but inspection is recommended, and the sixth to eighth segments represent good.

[0028] Table 1

[0029]

[0030] In one embodiment, the display module 18 may also be a display panel, and the control module 20 may display the detection status through the display panel, such as displaying the line resistance value, displaying the maximum open circuit voltage V OC , and corresponding text or image is displayed corresponding to one of the above-mentioned different resistance value ranges to form the prompt message to let the user know the quality of the power line. For example, the displayed text can be "good", "normal" or "abnormal".

[0031] In addition, in this embodiment, the electric circuit line quality detection device 1 also includes two temperature sensors 30, 32, the two temperature sensors 30, 32 are electrically connected to the control module 20, one temperature sensor 30 detects the temperature of the load resistor 14, and the other temperature sensor 32 detects the temperature of the rectifier module 22. During the detection mode, when the temperature of the load resistor 14 or the temperature of the rectifier module 22 is greater than a predetermined temperature, the control module 20 controls the switch element 16 to be turned off to stop detecting the load voltage VL and the line resistance value. The predetermined temperature can be set to be above 50 to 60 degrees. In addition, since the resistance value of the load resistor 14 will change slightly due to temperature changes, after the temperature of the load resistor 14 is detected by the temperature sensor 30, the control module 20 can use the measured temperature to fine-tune the stored resistance value of the load resistor 14, thereby correcting the load current flowing through the load resistor 14, so that the calculation of the line resistance value can be more accurate.

[0032] In addition, in the present embodiment, the control module 20, when in the detection mode, first detects whether the voltage and frequency of the AC power are within a normal voltage value range (90 volts to 250 volts) and a normal frequency value range (47 Hz to 63 Hz). If they are within the normal voltage value range and the normal frequency value range, the subsequent detection and calculation of the line resistance value are performed; otherwise, if they exceed the normal voltage value range or the normal frequency value range, the detection and calculation of the line resistance value are stopped, and a message corresponding to the voltage abnormality or frequency abnormality is displayed through the display module (such as the first to eighth LEDs are all red or orange and flashing).

[0033] The detection mode of this embodiment can be performed once after the power is turned on, and then the control module automatically performs the detection mode every predetermined time (such as 30 days). Alternatively, the electric circuit line quality detection device 1 also includes a manual start switch 34, which is electrically connected to the control module 20. The user presses the start switch 34 to start the start switch 34, and the control module 20 performs the detection mode. Before performing the detection mode, the control module 20 does not perform the detection mode if the temperature of any of the temperature sensors is greater than the predetermined temperature.

[0034] The electrical circuit line quality detection device 1 may also include a wireless communication module 36, and the wireless communication module 36 is electrically connected to the control module 20. The control module 20 can communicate with an external electronic device through the wireless communication module 36. The control module 20 sends a line message to the electronic device through the wireless communication module 36, and the line message at least includes the line resistance value, and may also include the maximum open circuit voltage and the resistance value range to which the line resistance value belongs.

[0035] Figure 3 The figure shows an electric circuit line quality detection device 2 of a second preferred embodiment of the present invention, which has a substantially similar structure to the first embodiment, except that the rectifier module 38 of this embodiment is a half-wave rectifier module, and the rectifier module 38 is electrically connected between one of the electrical connectors 12 and the load resistor 14, and the half-wave rectifier module can be, for example, a rectifier diode. One end of the load resistor 14 is electrically connected to one of the two electrical connectors 12 through the rectifier module 22, and the second end of the switch element 16 is directly electrically connected to the other of the two electrical connectors 12.

[0036] Figure 4The third preferred embodiment of the present invention is shown as an electric circuit line quality detection device 3, which has a substantially similar structure to the first embodiment, except that the rectifier module 22 is not provided, one end of the load resistor 14 is electrically connected to one of the two electrical connectors 12, and the second end 164 of the switch element 16 is directly electrically connected to the other of the two electrical connectors 12. The control module 20 of this embodiment can also detect the change of the voltage waveform, preferably, the peak voltage of the positive half-wave is used as the maximum open circuit voltage V OC or the load voltage V L .

[0037] As described above, the electric circuit line quality detection device of the present invention can not only accurately measure the line resistance of the overall circuit of the socket and the power line, but also provide corresponding information. It is small in size and easy to carry. It only needs to be plugged into the socket to detect the line resistance of the circuit loop corresponding to the socket, so that the user can easily and quickly know the quality of the current power line.

[0038] The above description is only a preferred feasible embodiment of the present invention. Any equivalent changes made by applying the present invention specification and the scope of patent application should be included in the patent scope of the present invention.

[0039] Description of Reference Numerals

[0040] [The present invention]

[0041] 1: Electrical circuit quality detection device

[0042] 10: Shell

[0043] 12: Electrical connectors

[0044] 14: Load resistance

[0045] 16: Switching element

[0046] 162: First End

[0047] 164: Second End

[0048] 18: Display module

[0049] 20: Control module

[0050] 22: Rectifier module

[0051] 24: Voltage divider circuit

[0052] 26: Voltage divider circuit

[0053] 28: Power supply module

[0054] 30: Temperature sensor

[0055] 32: Temperature sensor

[0056] 34: Start switch

[0057] 36: Wireless communication module

[0058] 2: Electrical circuit quality detection device

[0059] 38: Rectifier module

[0060] 3: Electrical circuit quality detection device

[0061] 100: socket

[0062] 200: Power Line

[0063] 300: AC power supply

[0064] N1, N2: nodes

[0065] T on : On time

[0066] V OC : Maximum open circuit voltage

[0067] V L : Load voltage

Claims

1. An electric circuit line quality detection device, used to connect a socket, and the socket is connected to two power lines, and the two power lines are connected to an AC power source, the electric circuit line quality detection device comprising: two electrical connectors, respectively connected to the sockets to receive the AC power from the AC power source through the two power lines; a load resistor, one end of which is electrically connected to one of the two electrical connectors, wherein: The load resistor is a power resistor; a switch element having a first end and a second end, wherein the first end is electrically connected to the other end of the load resistor, and the second end is electrically connected to the other of the two electrical connectors; a display module; A control module electrically connects the two ends of the load resistor, the switch element and the display module to perform a detection mode. In the detection mode, the control module controls the switch element to be cut off, detects the peak voltage in a half-wave of a voltage waveform of the alternating current and records it as a maximum open-circuit voltage, and then maintains the switch element to be cut off when the voltage waveform is lower than 0.8 times the peak voltage of the voltage waveform within a half-wave cycle after detecting the peak voltage of the voltage waveform, until the switch element is controlled to be turned on when the voltage waveform is more than 0.8 times the peak voltage, and detects the peak voltage in the voltage waveform during a conduction time and records it as a load voltage, and calculates a load current flowing through the load resistor; the control module calculates a line resistance value of the socket and the two power lines according to the maximum open-circuit voltage, the load voltage and the load current, and displays a message corresponding to the line resistance value through the display module.

2. The electrical circuit line quality detection device as claimed in claim 1, wherein: It includes a rectifier module electrically connected between one of the two electrical connectors and the load resistor. The rectifier module converts the AC power of the AC power source into DC power, and one end of the load resistor is electrically connected to one of the two electrical connectors through the rectifier module.

3. The electrical circuit line quality detection device as claimed in claim 2, wherein: The rectifier module is a full-wave rectifier module.

4. The electrical circuit line quality detection device as claimed in claim 2, wherein: The rectifier module is a half-wave rectifier module.

5. The electrical circuit line quality detection device as claimed in claim 1, wherein: When the switch element is turned off, the control module detects the frequency or period of the voltage waveform, and after obtaining the maximum open-circuit voltage, controls the switch element to turn on for the on-time according to the measured frequency or period.

6. The electrical circuit quality detection device according to claim 5, wherein: The conduction time does not exceed one half-wave period of the voltage waveform.

7. The electrical circuit line quality detection device as claimed in claim 1, wherein: A temperature sensor is included, which is electrically connected to the control module. The temperature sensor detects the temperature of the load resistor. When the temperature of the load resistor is greater than a predetermined temperature, the control module controls the switch element to be turned off.

8. The electrical circuit line quality detection device as claimed in claim 2, wherein: A temperature sensor is included, which is electrically connected to the control module. The temperature sensor detects the temperature of the rectifier module. When the temperature of the rectifier module is greater than a predetermined temperature, the control module controls the switch element to be turned off.

9. The electrical circuit line quality detection device as claimed in claim 1, wherein: A start switch is included, which is electrically connected to the control module. After the start switch is started, the control module performs the detection mode.

10. The electrical circuit line quality detection device as claimed in claim 1, wherein: The control module performs the detection mode once every predetermined period of time.

11. The electrical circuit line quality detection device according to claim 1, wherein: The control module compares the circuit resistance value with a plurality of resistance value ranges to determine the resistance value range to which the circuit resistance value belongs, and displays the corresponding message on the display module according to the resistance value range to which it belongs.

12. The electrical circuit line quality detection device as claimed in claim 1, wherein: A wireless communication module is included, which is electrically connected to the control module. The control module sends a line message through the wireless communication module, and the line message includes the line resistance value.

13. The electrical circuit line quality detection device as claimed in claim 1, wherein: It includes a temperature sensor electrically connected to the control module, the temperature sensor detects the temperature of the load resistor; the control module stores the resistance value of the load resistor, and the control module adjusts the stored resistance value of the load resistor according to the temperature measured by the temperature sensor, and calculates the load current flowing through the load resistor based on the adjusted resistance value of the load resistor.

14. The electrical circuit line quality detection device as claimed in claim 1, wherein: When the control module is in the detection mode, it first detects whether the voltage of the AC power is within a normal voltage value range. If it is within the normal voltage value range, it then detects and calculates the line resistance value. If it exceeds the normal voltage value range, it stops detecting and calculating the line resistance value, and displays a message corresponding to the voltage abnormality through the display module. In addition, the normal voltage value range is between 90 volts and 250 volts.

15. The electrical circuit line quality detection device as claimed in claim 1, wherein: When the control module is in the detection mode, it first detects whether the frequency of the alternating current is within a normal frequency value range. If it is within the normal frequency value range, it then detects and calculates the line resistance value. If it exceeds the normal frequency value range, it stops detecting and calculating the line resistance value, and displays a message corresponding to the frequency abnormality through the display module. In addition, the normal frequency value range is between 47 Hz and 63 Hz.

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