A multifunctional in-wall ac wire tracer

Abstract

The utility model discloses a wall inside alternating current wire tracer, including plastic shell, electronic amplification circuit board, alternating current signal induction coil, power component, the plastic shell is made with PVC pipe, is equipped with electronic amplification circuit board, alternating current signal induction coil, power component, has buzzer, pilot lamp, two button switch, charging seat opening, top inlay flashlight head, tail female screw seal cover, electronic amplification circuit board, use input impedance high junction strong effect pipe as preposition, darlington pipe as middle place, power amplification uses 8050, effectively promotes the work of audible -visual annunciator, the induction coil is no suction soft magnetism body core on lacquering pure preparation of wire, and the magnetic core coil can improve the sensitivity of inductive alternating current signal, power component comprises a lithium battery, C mouth charge -discharge module and flashlight head, the utility model discloses circuit is simple, need not debugging, and the function is various, not only can find the wall inside electric wire, can also judge zero line fire line, electric wire on -off, can be used as flashlight usually.

Description

Technical Field

[0001] This utility model relates to the field of electrical installation and maintenance technology, and in particular to a test tool for tracing the direction of concealed AC wiring inside a wall. Background Technology

[0002] When renovating or repairing a home, it is often necessary to chisel walls, drill holes, or cut grooves. If the original wiring routes are unknown, it is easy to hit the wiring inside the wall with an impact hammer or water drill, causing a short circuit between the wiring and the hammer / drill. This can result in electric shock to the operator or a fall from the scaffold after being shocked, causing secondary injuries. In severe cases, it can lead to personal injury or death.

[0003] Currently, the minimum depth for electrical wiring within walls in home decoration is 40mm. If tiling is used, it needs to be at least 60mm-70mm deep. Various non-contact inductive test pens are available on the market for measuring the live and neutral wires of AC power. While they are quite sensitive when close to the power line or touching the insulation layer, they are ineffective for detecting concealed wiring within walls, relying solely on the distribution of conduits. Multifunctional wall detectors produced by companies like Delixi, Uni-Trend, and Chint can detect magnetic wall materials such as steel reinforcement. While these instruments are advertised to detect wiring within walls at a depth of 40mm, actual tests show acceptable sensitivity on shallow surfaces. However, their effectiveness drops significantly on thicker mortar walls and insulated conduits, let alone tiled walls. This suggests that the advertised depth is a peak value or may be inflated. Furthermore, the high price is also a bottleneck. Therefore, it is essential to invent a highly sensitive in-wall AC concealed wiring tracing device. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a non-contact, multi-functional wall-mounted AC wire locator, which effectively solves the shortcomings of existing technologies and can replace commercially available induction and traditional voltage testers.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A multifunctional wall-mounted AC power cord tracker, comprising a plastic shell, an electronic amplifier circuit board, an induction coil, and a power supply assembly; wherein, the plastic shell is made of PVC material, the tube body is hollow, the amplifier circuit board, the induction coil, and the power supply assembly are installed inside the tube, and the outside of the tube has an air vent for an audible and visual alarm buzzer, an indicator light observation hole, two button switch holes, and a charging port, with a flashlight head embedded at the top; the amplifier circuit board uses a high input impedance and low noise junction field-effect transistor as the preamplifier, a Darlington transistor for intermediate amplification, and a power transistor for output amplification in the third stage; the induction coil is composed of a nickel-zinc ferrite core and enameled wire, and the two are stacked and installed at the front of the tube body, with the induction coil below and the amplifier circuit board above, and a vertical slot is correspondingly opened at the induction coil location; the audible and visual alarm buzzer on the board has an air vent on the front of the shell, and an indicator light exposure hole is made behind the air vent; the power button switch hole is opened in the middle of the tube body; the power supply assembly is an 18650 The lithium battery is placed at the rear of the tube; the additional flashlight head is embedded at the top of the tube; the C-port charging and discharging module is placed in front of the 18650 lithium battery, and a horizontal hole for the charging C-port is opened on the tube above the module; the self-locking button switch of the flashlight head is opened behind the power button switch; the audible and visual alarm, two control switches, and the opening for the charging C-port are on the central axis of the front of the tube.

[0006] The plastic shell is made of PVC material, and the tube is hollow with a diameter of 25mm and a length of 180mm. Inside the tube, there is an amplification circuit board, an induction coil, and a power supply assembly. On the outside of the tube, there are air vents for an audible and visual alarm buzzer, an indicator light observation hole, two button switch operation holes, and a charging port. A flashlight head is embedded at the top, and the tail end is sealed with a female screw cap.

[0007] The amplifier circuit board adopts a three-stage amplifier circuit. The first stage uses a junction field-effect transistor (JFET) for pre-amplification of the signal. The JFET has high input impedance and low noise characteristics and can directly couple AC signals inside the wall. The second stage uses a Darlington transistor for intermediate amplification. The third stage uses a power transistor for output amplification to drive the LED light and the buzzer for audible and visual alarm. All components are soldered on a 50mm long and 15mm wide porous copper-clad board. The detection switch is controlled by a push-button switch.

[0008] The induction coil has a built-in nickel-zinc ferrite core wound with 0.5mm diameter enameled wire. The frame is made of paper or plastic tube, 50mm long, 5mm inner diameter, and 6mm outer diameter, wound with 250-300 turns. Then, a 50mm long, 5mm diameter nickel-zinc ferrite core is inserted, making the coil inductance 1.2-1.5mH. Compared with an air-core coil, the magnetic core coil can improve sensitivity, reduce noise, and save costs.

[0009] The power supply assembly consists of an 18650 lithium battery and a USB-C charging / discharging module, with a self-locking push-button switch controlling the on / off state of the flashlight head.

[0010] The implementation of the above technical solution represents a new breakthrough in the testing of concealed AC wiring within walls. Compared with existing technologies, the beneficial effects of this utility model are: Firstly, it provides a multifunctional AC wire tracing device within walls that can test the distribution of AC wires within 100mm of the wall; secondly, it provides audible and visual alarms, combining sight and sound; thirdly, it is versatile and highly practical, not only locating wires within walls but also identifying live and neutral wires, and detecting wire breaks, and can be used as a flashlight; fourthly, the circuit of this utility model is simple, requires no debugging, is low in cost, and easy to manufacture. Attached Figure Description

[0011] Figure 1 is a side view of the present invention.

[0012] Figure 2 is a schematic diagram of the electronic amplifier circuit of this utility model.

[0013] Figure 3 is a schematic diagram of the induction coil of this utility model.

[0014] Figure 4 is a diagram of the power supply component of this utility model.

[0015] Figure 5 is a front view of this utility model.

[0016] In the diagram: 1. Plastic casing; 2. Amplifying circuit board; 3. Induction coil; 4. Power supply assembly; 5. Enameled wire; 6. Nickel-zinc ferrite core; 7. Audible and visual alarm; 8. Push-button switch; 9. 18650 lithium battery; 10. Port C charging and discharging module; 11. Flashlight head; 12. Self-locking push-button switch; 13. Female screw back cover. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. It should be noted that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the updating of the present utility model.

[0018] Referring to Figures 1-5, this utility model provides a technical solution: a multifunctional wall-mounted AC wire locator, consisting of a plastic shell (1), an amplifying circuit board (2), an induction coil (3), and a power supply assembly (4); the plastic shell (1) is made of PVC material, with a hollow tube body, and the amplifying circuit board (2), induction coil (3), and power supply assembly (4) are installed inside the tube. The tube has an audible and visual alarm (7) buzzer vent, an indicator light observation hole, a two-button switch operation hole, and a charging port on the outside. A flashlight head (11) is embedded at the top, and the tail end is sealed with a female screw cap (13). The amplifier circuit board (2) and the induction coil (3) are stacked and installed at the front of the tube body, with the induction coil (3) at the bottom and the amplifier circuit board (2) at the top. A vertical groove is opened at the bottom position corresponding to the induction coil (3) to expose the coil so as to facilitate the sensing of AC signals inside the wall. The sound and light alarm (7) buzzer on the board has a vent hole and an indicator light observation hole on the front of the outer shell. The power control button switch (8) hole is opened at the front of the middle of the tube body. The power component (4) and the 18650 lithium battery (9) are placed at the rear of the tube body. The additional flashlight head (11) is embedded at the top of the tube body, which is both beautiful and practical. The C port charging and discharging module (10) is placed in front of the lithium battery (9) and can be used as a baffle to prevent the 18650 lithium battery (9) from sliding forward. A C port horizontal hole is opened on the tube body above the module. The self-locking button switch (12) of the flashlight head is opened behind the amplifier board button switch (8). The sound and light alarm, two control switches, and charging C port opening are on the central axis of the front of the tube body.

[0019] Selection of exposed components and polishing of plastic housing (1): The alarm indicator light is selected as a red LED with a diameter of 5mm, the push button switch (8) and the self-locking push button switch (12) are selected as 1208YD type, the charging and discharging module (10) is selected as the type with TYPE-C female connector, the flashlight head (11) is selected as the 5W bracket type with a diameter of 20mm and a height of 20mm; the plastic housing (1) is a PVC plastic tube with an inner diameter of 20mm and a length of 180mm, of which 20mm is reserved at the top for installing the flashlight head (11), and the amplifier board (2) and the induction coil (3) are installed at the front 50mm. The buzzer vent and indicator light hole are opened on the amplifier board, with a distance of 10mm between them. The vent is multi-hole with a diameter range of 10mm. The LED indicator light (7) has a hole diameter of 5mm. A slot with a length of 50mm and a width of 5mm is opened under the induction coil (3) for the purpose of exposing the induction coil (1) and effectively sensing the AC signal. Two slots with a diameter of 7mm are opened at the middle section of 45mm. Holes, with the midpoints of the two holes 9mm apart, are used to install push button switches (8) and self-locking push button switches (12) respectively. The distance from the rear switch is 8mm. A horizontal hole of 8mm×3mm is opened to install the charging and discharging module (10) C port. The rear 65mm is the position of the 18650 lithium battery (9). Then, 5 turns of external thread are tapped at the end of the tube and the end is sealed with the matching female screw cover (13).

[0020] In this embodiment, the performance of the amplification circuit board (2) is as follows: the first stage uses a junction field-effect transistor (JFET) for signal amplification. Among them, 2SK246 is an N-channel junction field-effect transistor (JFET) with high input impedance and low noise characteristics. It directly couples the AC signal inside the wall through the induction coil (1) and is suitable for preamplification. It senses the AC signal inside the wall. The replacement models are 2N3821, K170, etc. Using a JFET for preamplification is irreplaceable by other low-power transistors. This is also another reason why some induction test pens have shallow sensing distances. The intermediate amplification uses a Darlington transistor MPSA13, which can save one or two discrete transistors. The power amplification uses SS8050 output to drive the sound and light alarm. Its advantages are reflected in the ability of low voltage and high current, as well as the stable performance in low-power applications.

[0021] Furthermore, the amplification circuit board (2) is fabricated. According to the circuit schematic, all components of the amplification circuit are soldered onto a 50mm long and 15mm wide perforated copper plate and the circuit is connected. The LED indicator (7) is 3mm higher than the circuit board, and the installation height of other components including the circuit board is 10mm. The negative wire is led out from the circuit board. One end of the detection button switch (8) is connected to the positive terminal of the circuit board, and the other end is left with a lead wire.

[0022] In this embodiment, the quality of the induction coil (3) is crucial to the success of the tracker, directly affecting the sensitivity and depth of the AC signal within the induction wall. This cannot be compensated for by increasing the amplifier gain. A nickel-zinc ferrite core (6) is selected because it is a soft magnetic material without attraction, without residual magnetic interference, with superior high-frequency performance, and fast response, making it suitable for non-contact AC signal induction. Compared to an air-core coil, the magnetic core coil can increase the inductance by 10%. 3 When detecting low-frequency signals, the output voltage of the magnetic core coil is 30dB higher than that of the air core coil, which improves sensitivity, reduces noise, and saves costs. The selection of the enameled wire diameter (5) is also very important. The number of turns affects the inductance, while the wire diameter affects the resistance and performance of the inductor. When the number of turns is fixed, if the wire diameter is thicker, the coil volume will increase to reach a certain inductance. Similarly, if the wire diameter is thinner, the coil resistance will also increase to reach a certain number of turns, which will affect the performance of the inductor. Most commercially available induction measuring devices use screwdrivers or air core coils with a small number of turns as the sensing head, which will greatly reduce the sensing distance.

[0023] Furthermore, the induction coil (3) is made by winding enameled wire (5) with a diameter of 0.5-0.8mm. It can be wound directly on the magnetic core or by using a frame. The advantage of using a frame is that the inductance of the coil can be adjusted by moving the magnetic core. The frame is made of paper tube or plastic tube, 50mm long, 5mm inner diameter, and 6mm outer diameter. Hard paper discs with holes in the center are glued to both ends of the tube to prevent the coil winding from slipping out. 250-300 turns are wound flat, and then a nickel-zinc ferrite magnetic column (6) with a length of 50mm and a diameter of 5mm is inserted to make the coil inductance 1.2-1.5mH. The diameter of the wound coil is 8mm.

[0024] In this embodiment, the power supply component (4) consists of an 18650 lithium battery (9) and a C-port charging and discharging module (10); the additional flashlight head (11) is used to decorate the top of the tracker and is used as a flashlight. The negative terminal of the flashlight head (11) is connected to the negative terminal of the amplifier circuit board (2), and the positive terminal is connected to one end of the button self-locking switch (12). The other end of the switch has a lead wire.

[0025] The lithium battery used in this amplifier circuit is fully charged to 4.2V, but it can actually work normally at 3-6V. Since the circuit voltage is low, there is no need to design or adjust the pre-bias voltage value. The gain of the three amplifier transistors is selected as follows: K246 is 40 times, A13 is 70 times, and 8050 is 200 times.

[0026] For the installation of the tracker, first pass the two control switches, the flashlight head, and the negative lead of the amplifier circuit board (2) through the plastic shell (1), then place the LED light (7) on the amplifier circuit board (2), then push the induction coil (1) into place along the slot, and then insert it into the flashlight head (11); apply glue to the two button switch seats to fix them in their respective holes, solder the positive leads of the two switches and the positive terminal of the 18650 lithium battery (9) to the positive terminal of the charging and discharging module (10), solder the negative lead of the amplifier circuit board (2) and the negative terminal of the 18650 lithium battery (9) to the negative terminal of the charging and discharging module (10), fix the charging and discharging module (10) with glue, and make the C-type connector flush with the tube surface, insert the lithium battery (9), and then screw on the female screw back cover (13).

[0027] Tracker working principle: Referring to Figure 2, the schematic diagram of the electronic amplifier circuit, when the power switch SA is turned on, the amplifier circuit is cut off and does not work when there is no induction signal inside the wall, and the tracker has no audible or visual alarm. When the induction coil senses the AC signal inside the wall, it is coupled to the gate of the 2SK246 through C. The amplified AC signal is matched by the impedance of R2 and enters MPSA13 for secondary amplification. It is then directly coupled to the power transistor SS8050 for tertiary amplification and output from the collector to drive the LED to light up and flash, and the buzzer to sound an alarm. Pressing the self-locking button switch turns on the flashlight for illumination.

[0028] To use the tracker, close the main power box in your home, turn on the individual room switches, press and hold the tracker button switch (8), place the tracker induction coil (1) close to the wall where you want to drill a hole, and slowly move the tracker horizontally or vertically. The place where there is an audible and visual alarm is the location of the AC wire. The place where there is no audible and visual alarm is the safe place to drill a hole. To determine the live and neutral wires, since the tracker is highly sensitive, you must use a wire or test lead to pull out a single power wire from the wall for testing. The wire that can trigger an audible and visual alarm is the live wire, and the wire that does not trigger an alarm is the neutral wire. The principle of breaking wire detection is the same as testing the live wire. The place where no alarm is detected is the broken wire point. However, when testing the neutral wire, you need to turn the neutral wire segment into the live wire. The flashlight is frequently used by electricians. Just turn on the flashlight self-locking button switch (12). To charge the tracker, plug the 5V mobile phone charging head type-c charging cable into the matching C port of the charging and discharging module (10). It will automatically stop when fully charged.

[0029] The embodiments described above are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, those skilled in the art can, without creative effort, change the models of the amplifier circuit components, such as replacing the last two stages of amplification with operational amplifiers or other transistors, using only air-core or other shapes for the induction coil, or adding an adjustable potentiometer to the intermediate amplification. These actions are equivalent substitutions or invalid changes and are all within the scope of protection of this utility model.

Claims

1. A multifunctional in-wall AC wire locator, characterized in that... This tracker consists of a plastic shell (1), an amplifying circuit board (2), an induction coil (3), and a power supply assembly (4). The plastic shell (1) is made of PVC material, hollow, with a diameter of 25mm and a length of 180mm. Inside the tube are the amplifying circuit board (2), the induction coil (3), and the power supply assembly (4). Outside the tube are an air vent for an audible and visual alarm (7) buzzer, an indicator light observation hole, a two-button switch operation hole, and a charging port. A flashlight head (11) is embedded at the top, and the tail end is sealed with a female screw cap. The amplifying circuit board (2) uses a high input impedance and low noise junction field-effect transistor as the preamp and a Darlington transistor as the intermediate amplifier. The third stage uses a power tube for output amplification. The induction coil (3) is composed of a nickel-zinc ferrite core (6) and enameled wire (5). The two are stacked and installed at the front of the tube body. The induction coil (3) is below and the amplification circuit board (2) is above. A vertical slot is opened at the induction coil (3) location. The sound and light alarm (7) buzzer on the board has an air hole on the front of the shell. An indicator light hole is opened behind the air hole. The power button switch (8) hole is opened in the middle of the tube body. The power component (4) is an 18650 lithium battery (9) and is placed at the rear of the tube body. The additional flashlight head (11) is embedded at the top of the tube body. The C port charging and discharging module (10) is placed in front of the 18650 lithium battery (9) and a horizontal hole for the charging C port is opened on the tube body above the module. The self-locking button switch (12) of the flashlight head is opened behind the power button switch (8). The sound and light alarm, two control switches, and the charging C port opening are on the central axis of the front of the tube body.

2. A multifunctional in-wall AC wire locator according to claim 1, characterized in that: The amplifier circuit board (2) adopts a three-stage electronic amplifier circuit to drive the LED lamp and the buzzer for sound and light alarm. All components are soldered on a 50mm long and 15mm wide multi-hole copper plate. The detection switch is controlled by a push-button switch (8).

3. The multifunctional in-wall AC wire locator according to claim 1, characterized in that: The induction coil (3) has a built-in nickel-zinc ferrite core (6) and is wound with enameled wire (5) with a diameter of 0.5 mm. The frame is made of paper tube or plastic tube, 50 mm long, 5 mm inner diameter, and 6 mm outer diameter, and is wound flat for 250-300 turns. Then, a nickel-zinc ferrite core (6) with a length of 50 mm and a diameter of 5 mm is inserted to make the coil inductance 1.2-1.5 mH.

4. A multifunctional in-wall AC wire locator according to claim 1, characterized in that: The power supply component (4) consists of an 18650 lithium battery (9) and a C-port charging and discharging module (10). The self-locking button switch (12) controls the on / off state of the flashlight head (11).

5. A multifunctional in-wall AC wire locator according to claim 1 or 3, characterized in that: The nickel-zinc ferrite core (6) of the induction coil (3) is a soft magnet without attraction.

6. A multifunctional in-wall AC wire tracing device according to claim 1 or 2, characterized in that: The first stage of the electronic amplifier circuit board (2) uses a junction field-effect transistor 2SK246, which is an N-channel junction field-effect transistor with high input impedance and low noise characteristics, and directly couples AC signals inside the wall.

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