WO2021119751A1

WO2021119751A1 - Voltage detection apparatus and method

Info

Publication number: WO2021119751A1
Application number: PCT/AU2020/051391
Authority: WO
Inventors: Shane BALLINGALL; Karl ROSEWARNE; Gary Sargeant; Richard Kabzinski
Original assignee: Protective Innovations Pty Ltd
Priority date: 2019-12-18
Filing date: 2020-12-18
Publication date: 2021-06-24
Also published as: AU2020410098A1

Abstract

Provided is voltage detection apparatus (10) which comprises a detection antenna module (12) configured for detecting an electrical field via electrical induction, an analogue discriminator (14) arranged in signal communication with the antenna module (12) and configured to discriminate a magnitude of the electrical field. Apparatus (10) also includes a microcontroller (16) arranged in signal communication with the analogue discriminator (14) and configured with a frequency discriminator (18) configured to discriminate a frequency of the electrical field, as well as an audible and/or visual notifier (20) actuatable by the microcontroller (16) and configured to notify a user. Apparatus (10) includes a transmission module (22) arranged in signal communication with the microcontroller (16) and configured to transmit a notification signal. In this manner, if the magnitude of the electrical field exceeds a predetermined value, the analogue discriminator (14) is configured to activate the microcontroller (16), and if the frequency of the electrical field falls within a predetermined range, the microcontroller (16) is configured to actuate the notifier (20) and transmission module (22).

Description

VOLTAGE DETECTION APPARATUS AND METHOD

TECHNICAL FIELD

[0001] This invention broadly relates to the field of electrical safety, and more specifically to a voltage detection apparatus for detecting live mains voltage and an associated voltage detection method.

BACKGROUND ART

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0003] Electrical safety is a vital consideration in any electrical system. For this reason, it is often necessary to determine if an electrical voltage or associated electrical field is present in a conductor or device before approaching or accessing such a conductor or device in order to protect a user from accidental electric shock. Various devices have been devised over the years for checking for the presence of voltage, such as test lights, meters, etc.

[0004] A shortcoming with known devices is that such devices can often not discriminate a particular type of voltage or electrical field, such as static charges (which are typically not dangerous), with live mains power, which is. In addition, known devices are either very rudimentary, with associated shortcomings in detection abilities, or very complicated, making them expensive and difficult to use without training.

[ 0005 ] The Applicant has identified a need for a simple and elegant way to accurately detect and report dangerous voltages and the current invention was conceived with the known shortcomings in mind.

SUMMARY OF THE INVENTION

[ 0006 ] According to a first aspect of the invention there is provided voltage detection apparatus comprising: a detection antenna module configured for detecting an electrical field via electrical induction; an analogue discriminator arranged in signal communication with the antenna module, said analogue discriminator configured to discriminate a magnitude of the electrical field; a microcontroller arranged in signal communication with the analogue discriminator and configured with a frequency discriminator configured to discriminate a frequency of the electrical field; an audible and/or visual notifier actuatable by the microcontroller and configured to notify a user; and a transmission module arranged in signal communication with the microcontroller and configured to transmit a notification signal; wherein if the magnitude of the electrical field exceeds a predetermined value, the analogue discriminator is configured to activate the microcontroller; and wherein if the frequency of the electrical field falls within a predetermined range, the microcontroller is configured to actuate the notifier and transmission module. [0007] Typically, the detection antenna module comprises a suitable waveguide adapted for electromagnetic field induction when brought into proximity with the electrical field.

[0008] Typically, the analogue discriminator comprises low- power logic circuitry along with resistive and capacitive elements to form a voltage comparator which, when the magnitude of the electrical field induced in the detection antenna module exceeds the predetermined value, an activation input of the microcontroller is pulled to a high state.

[0009] In one example, the low-power logic circuitry comprises two inverters with resistive and capacitive elements that are arranged as a voltage comparator with the antenna module.

[0010] Typically, the microcontroller is configured with an ultra-low power sleep mode and only activated once the magnitude of the electrical field exceeds a predetermined value in order to reduce energy consumption.

[0011] Typically, the frequency discriminator comprises a digital filter configured within the microcontroller, so that said frequency discriminator only discriminates the frequency of the electrical field when the microcontroller is active in order to reduce energy consumption.

[0012] Typically, the digital filter of the frequency discriminator comprises a bandpass filter. [0013] Typically, the predetermined frequency range within which the microcontroller actuates the notifier and transmission module is between 45Hz to 65Hz.

[0014] Typically, the predetermined frequency range is between 50Hz and 60Hz.

[0015] Typically, the audible notifier comprises a piezo transducer or speaker.

[0016] Typically, the visual notifier comprises a light emitting diode (LED).

[0017] In one embodiment, the microcontroller is configured to actuate the notifier at a particular intensity according to a magnitude of the detected electrical field.

[0018] Typically, the transmission module comprises a

Bluetooth Low Energy (BLE) module.

[0019] Typically, the notification signal is transmitted to a mobile phone handset or tablet configured with a suitable application or app which logs a geographical location (via a handset global navigation satellite system or GNSS sensor of the handset/tablet) of the handset and the magnitude and/or frequency of the detected electrical field.

[0020] Typically, the apparatus includes a housing wherein the antenna, microcontroller, notifier, transmission module and discriminators are housed.

[0021] In one embodiment, the housing includes an abutment portion for operatively abutting against a conductor, the microcontroller configured to calculate a voltage magnitude of the detected electrical field as a distance between the conductor and abutment portion is predetermined and known.

[0022] Typically, the housing defines a mount for operatively mounting to an insulation stick with which the abutment portion is able to be brought into abutment with a conductor.

[0023] In an embodiment, the housing defines a mount and/or is suitably configured to mount to a tool, a piece of equipment and/or an article of clothing to alert a user of dangerous electrical fields when using, operating or wearing such tool, piece of equipment or article of clothing, respectively.

[0024] Typically, the apparatus includes energising means for electrically energising the microcontroller, notifier, transmission module and discriminators, as required.

[0025] According to a second aspect of the invention there is provided a voltage detection method comprising the step of: detecting, via a detection antenna module, an electrical field via electrical induction; discriminating, via an analogue discriminator, a magnitude of the electrical field; if the magnitude of the electrical field exceeds a predetermined value, activating a microcontroller configured with a frequency discriminator in order to discriminate a frequency of the electrical field; if the frequency of the electrical field falls within a predetermined range, actuating, via the microcontroller, an audible and/or visual notifier to notify a user and a transmission module to transmit a notification signal. [0026] Typically, the detection antenna module comprises a suitable waveguide adapted for electromagnetic field induction when brought into proximity with the electrical field.

[0027] Typically, the analogue discriminator comprises low- power logic circuitry along with resistive and capacitive elements to form a voltage comparator which, when the magnitude of the electrical field induced in the detection antenna module exceeds the predetermined value, an activation input of the microcontroller is pulled to a high state.

[0028] In one example, the low-power logic circuitry comprises two inverters with resistive and capacitive elements that are arranged as a voltage comparator with the antenna module.

[0029] Typically, the microcontroller is configured with an ultra-low power sleep mode and only activated once the magnitude of the electrical field exceeds a predetermined value in order to reduce energy consumption.

[0030] Typically, the frequency discriminator comprises a digital filter configured within the microcontroller, so that said frequency discriminator only discriminates the frequency of the electrical field when the microcontroller is active in order to reduce energy consumption.

[0031] Typically, the digital filter of the frequency discriminator comprises a bandpass filter. [0032] Typically, the predetermined frequency range within which the microcontroller actuates the notifier and transmission module is between 45Hz to 65Hz.

[0033] Typically, the predetermined frequency range is between 50Hz and 60Hz.

[0034] Typically, the audible notifier comprises a piezo transducer or speaker.

[0035] Typically, the visual notifier comprises a light emitting diode (LED).

[0036] In one embodiment, the microcontroller is configured to actuate the notifier at a particular intensity according to a magnitude of the detected electrical field.

[0037] Typically, the transmission module comprises a Bluetooth Low Energy (BLE) module.

[0038] In one embodiment, the method includes the step of calculating, via the microcontroller, a voltage magnitude of the detected electrical field if the detection antenna module is brought within a known distance of a conductor.

[0039] According to further aspects of the present invention there is provided voltage detection apparatus and a voltage detection method substantially are herein described and/or illustrated. BRIEF DESCRIPTION OF THE DRAWINGS

The description will be made with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic representation of voltage detection apparatus, in accordance with an aspect of the present invention;

Figure 2 is a diagrammatic representation of an example circuit layout of constituent parts of the voltage detection apparatus of Figure 1; and

Figure 3 is diagrammatic representation of method step for a method of voltage detection, in accordance with an aspect of the present invention;

DETAILED DESCRIPTION OF EMBODIMENTS

[0040] Further features of the present invention are more fully described in the following description of several non limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention to the skilled addressee. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. In the figures, incorporated to illustrate features of the example embodiment or embodiments, like reference numerals are used to identify like parts throughout.

[0041] With reference now to the accompanying figures, there is shown an embodiment of voltage detection apparatus 10, according to an aspect of the present invention. Apparatus 10 generally comprises a detection antenna module 12 which is configured for detecting an electrical field via electrical induction, as well as an analogue discriminator 14 which is arranged in signal communication with the antenna module 12, as shown. The detection antenna module 12 typically comprises a suitable waveguide adapted for electromagnetic field induction when brought into proximity with the electrical field, e.g. via capacitive coupling.

[ 0042 ] The analogue discriminator 14 is configured to discriminate a magnitude of the electrical field. As shown in Figure 2, the analogue discriminator generally comprises low- power logic circuitry along with resistive and capacitive elements to form a voltage comparator which, when the magnitude of the electrical field induced in the detection antenna module 12 exceeds the predetermined value, an activation input of a microcontroller 16 is pulled to a high state. In the exemplified embodiment, the low-power logic circuitry comprises two inverters with resistive and capacitive elements that are arranged as a voltage comparator with the antenna module. Variations hereon are possible and within the scope of the present invention.

[ 0043 ] The skilled addressee is to appreciate that the analogue discriminator 14 is responsive to an analogue signal, being the induced voltage within antenna module 12, while it outputs a digital binary on/off signal to the microcontroller 16. By appropriate design, the predetermined value for the magnitude of the electrical field can be set or determined. However, importantly, the analogue discriminator 14 can be realised using low-power components, such as a hex inverter or similar logic circuits. [0044] Apparatus 10 also includes microcontroller 16 which is arranged in signal communication with the analogue discriminator 14 and is configured with a frequency discriminator 18 which is configured to discriminate a frequency of the detected electrical field. In one example, the frequency discriminator 18 comprises a digital filter configured within the microcontroller 16, as shown, so that the frequency discriminator 18 only discriminates the frequency of the electrical field when the microcontroller 16 is activated by the analogue discriminator 14 in order to reduce energy consumption. Typically, the microcontroller 16 is configured with an ultra-low power sleep mode and is only activated by the analogue discriminator 14 once the magnitude of the electrical field exceeds a predetermined value in order to reduce energy consumption.

[0045] In one example, the digital filter of the frequency discriminator 18 comprises a bandpass filter. The predetermined frequency range within which the microcontroller 16 actuates the notifier 20 and transmission module 22 is generally between 45Hz to 65Hz, as mains live voltage has a frequency range between 50Hz and 60Hz. Variations hereon are possible and within the scope of the present invention.

[0046] Apparatus 10 further includes the audible and/or visual notifier 20 which is actuatable by the microcontroller 16 and is configured to notify a user, as well as the transmission module 22 which is arranged in signal communication with the microcontroller 16 and is configured to transmit a notification signal 24.

[0047] In this manner, if the magnitude of the detected electrical field exceeds a predetermined value, the low—power analogue discriminator 14 is configured to activate the microcontroller 16, and if the frequency of the electrical field falls within a predetermined range, such as 50Hz - 60Hz, the microcontroller 16 is configured to actuate the notifier 20 and transmission module 22.

[ 0048 ] Such a configuration provides for portable and lightweight apparatus 10 having extended battery life, as the analogue discriminator 14 can be realised with low-power components. Only once a certain magnitude electrical field is sensed, does the analogue discriminator 14 activate the microcontroller 16, which uses the frequency discriminator 18 to see if the detected voltage is potentially mains live voltage (having a specific frequency, rather than 'false alarm' static charges, or the like). If both electrical field magnitude and frequency satisfy the predetermined values, does the microcontroller 16 notify the user via the notifier 20 and transmission module 22.

[ 0049 ] In one example, the audible notifier comprises a piezo transducer or speaker, and the visual notifier comprises a light emitting diode (LED). In one embodiment, the microcontroller 16 is configured to actuate the notifier 20 at a particular intensity according to a magnitude of the detected electrical field, e.g. a higher frequency sound for higher magnitude fields, or a more rapidly flashing light for higher magnitudes, or the like.

[ 0050 ] The transmission module 22 typically comprises a Bluetooth Low Energy (BLE) module. In one embodiment, the notification signal 24 is transmitted to a mobile phone handset or tablet 32 configured with a suitable application or app which logs a geographical location (via a handset global navigation satellite system or GNSS sensor of the handset/tablet 32) and the magnitude and/or frequency of the detected electrical field. Such logging of sensed electrical fields can be useful for routine electrical line inspection, and the like.

[0051] The apparatus 10 generally includes a housing 26 wherein the antenna 12, microcontroller 16, notifier 20, transmission module 22 and discriminators 14 and 18 are housed.

[0052] In one embodiment, the housing 26 includes an abutment portion 28 for operatively abutting against a conductor, such as an electrical line. The microcontroller 16 is accordingly configured to calculate a voltage magnitude of the detected electrical field as a distance 30 between the conductor and abutment portion is known, e.g. zero, or some known distance, e.g. 5mm, or the like. As is known in the art, electric fields generated by voltages present in electrical conductors induce a signal in the detection antenna module 12, said signal proportional to the magnitude of the voltage and the proximity of the antenna 12 to the conductor. If the distance 30 is known, then the magnitude (and not just the presence) of the voltage can be calculated.

[0053] Accordingly, in one embodiment, the housing 26 defines a mount (not shown) for operatively mounting to an insulation stick, as known in the art, with which the abutment portion 28 is able to be brought into abutment with a conductor. For example, an isolation stick of 2m can be used to abut the apparatus 10 against a conductor to calculate a value of a voltage within said conductor. Similarly, on another embodiment the housing 26 may define a mount and/or is suitably configured to mount to a tool, a piece of equipment and/or an article of clothing to alert a user of dangerous electrical fields when using, operating or wearing such tool, piece of equipment or article of clothing, respectively. The microcontroller 16 can be configured to transmit such calculated voltage magnitude to handset 32, via the BLE module 22, or the like.

[ 0054 ] As will be appreciated by the skilled addressee, the apparatus 10 also generally includes energising means for electrically energising the microcontroller 16, notifier 20, transmission module 22 and discriminators 14 and 18, as required. Such energising means typically comprise an electrochemical cell or battery, such as button batteries, or the like.

[ 0055 ] Following the above broad description of one example of apparatus 10, a practical embodiment of the apparatus 10 may be implemented on printed circuit board or 'PCB' measuring approximately 20mm wide, 50mm long, and 5mm in height, making for a very compact and lightweight apparatus 10. The PCB contains analogue signal detection circuitry, i.e. the analogue discriminator 14, a combination microcontroller/BLE module, an audible buzzer, coin cell batteries, and two electrical interfaces. The electrical interfaces provide connections for the detection antenna 12 and microcontroller programmer .

[ 0056 ] The detection antenna 12 is connected to the PCB permanently via solder pads as a primary detection element and optional ground plane. Five test pads provide temporary access to a programming port of the microcontroller 16. A programming module combined with electrical probes configured for the positions of the test pads facilitates the uploading of firmware to the microcontroller 16. The PCB and detection antenna 12 are housed in a plastic enclosure or housing 26 designed for operative fitment to an insulating stick, a safety helmet, an article of clothing, or the like.

[ 0057 ] As described, the apparatus 10 is a compact, battery powered device designed to provide intelligent wireless detection of live mains voltages in dangerous proximity to a user. This is achieved by monitoring the electric field generated by voltages present in electrical conductors 8 and providing alerts to the user in the event that a dangerous voltage is detected. These alerts take the form of an audible alarm and a digital alarm flag transmitted wirelessly via BLE.

[ 0058 ] As described, the magnitude of the detected electrical field or signal is measured by the analogue portion of the circuit, i.e. the analogue discriminator 14, and if determined to be above a set threshold, passed to the microcontroller module 16. The microcontroller 16 measures the frequency of the signal to determine whether or not it is within the 50 - 60 Hz band of interest, typically at a 50Hz or 60Hz nominal frequency depending on the local power supply frequency. If the signal is within or at this frequency, a proximity alert is triggered. This frequency filtration stage prevents false alerts from static electricity. A proximity alert consists of an audible alarm and digital alarm transmitted via BLE, to be interpreted by a dedicated smartphone app or similar device. While the device is not detecting the presence of potentially dangerous voltage it remains in an ultra-low power sleep mode, consuming less than one microampere. Upon detection of potentially dangerous voltage, the microcontroller awakes and begins the alert process described previously. [0059] Of particular interest is that the microcontroller module 16 is generally in an ultra-low power sleep, and is configured to wake when a signal is received from the analogue detection circuitry 14. Upon waking, a frequency measurement is performed. If the signal is determined to be within the 50 - 60 Hz band, a proximity alert is triggered via an electrical output activating the audible buzzer, and the BLE transmission of a 'high alert' flag, as specified by the BLE protocol. If the signal is not within the band of interest, the microcontroller returns to ultra-low power sleep mode to preserve power.

[0060] Applicant has found that using two button batteries, such as CR2032 lithium batteries, apparatus 10 can be active for more than a year with reasonably regular use. During low- power standby where only the analogue discriminator 14 is active, current draw of less than 1 microampere is common, while full operation where the microcontroller 16 with frequency discriminator 18 and transmission module 22 are active, current consumption of 6 - 9milliampere occurs.

[0061] As shown in Figure 3, the skilled addressee is to appreciate that the present invention also includes an associated voltage detection method 40.

[0062] Broadly, method 40 comprises the steps of detecting, 42 via detection antenna module 12, an electrical field via electrical induction and discriminating 44, via analogue discriminator 14, a magnitude of the electrical field 46. If the magnitude of the electrical field exceeds a predetermined value, the method 40 includes the step of activating 48 microcontroller 16 which is configured with a frequency discriminator in order to discriminate a frequency 50 of the electrical field. If the frequency of the electrical field falls within a predetermined range 52, the microcontroller 16 actuates the audible and/or visual notifier to notify a user and a transmission module to transmit a notification signal 54. If either discrimination steps falls below the predetermined value, no action is taken 56 and 58, as relevant.

[0063] Applicant believes is particularly advantageous that the present invention provides for apparatus 10 which provides elegant detection of dangerous voltages via a double discrimination process which facilitates long battery life in a package which is lightweight and small.

[0064] Optional embodiments of the present invention may also be said to broadly consist in the parts, elements and features referred to or indicated herein, individually or collectively, in any or all combinations of two or more of the parts, elements or features, and wherein specific integers are mentioned herein which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth. In the example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail, as such will be readily understood by the skilled addressee.

[0065] The use of the terms "a", "an", "said", "the", and/or similar referents in the context of describing various embodiments (especially in the context of the claimed subject matter) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having, " "including, " and "containing" are to be construed as open- ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. No language in the specification should be construed as indicating any non-claimed subject matter as essential to the practice of the claimed subject matter.

[0066] It is to be appreciated that reference to "one example" or "an example" of the invention, or similar exemplary language (e.g., "such as") herein, is not made in an exclusive sense. Various substantially and specifically practical and useful exemplary embodiments of the claimed subject matter are described herein, textually and/or graphically, for carrying out the claimed subject matter.

[0067] Accordingly, one example may exemplify certain aspects of the invention, whilst other aspects are exemplified in a different example. These examples are intended to assist the skilled person in performing the invention and are not intended to limit the overall scope of the invention in any way unless the context clearly indicates otherwise. Variations (e.g. modifications and/or enhancements) of one or more embodiments described herein might become apparent to those of ordinary skill in the art upon reading this application. The inventor (s) expects skilled artisans to employ such variations as appropriate, and the inventor (s) intends for the claimed subject matter to be practiced other than as specifically described herein.

[0068] Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

Claims

1. Voltage detection apparatus comprising: a detection antenna module configured for detecting an electrical field via electrical induction; an analogue discriminator arranged in signal communication with the antenna module, said analogue discriminator configured to discriminate a magnitude of the electrical field; a microcontroller arranged in signal communication with the analogue discriminator and configured with a frequency discriminator configured to discriminate a frequency of the electrical field; an audible and/or visual notifier actuatable by the microcontroller and configured to notify a user; and a transmission module arranged in signal communication with the microcontroller and configured to transmit a notification signal; wherein if the magnitude of the electrical field exceeds a predetermined value, the analogue discriminator is configured to activate the microcontroller; and wherein if the frequency of the electrical field falls within a predetermined range, the microcontroller is configured to actuate the notifier and transmission module.

2. The apparatus of claim 1, wherein the detection antenna module comprises a suitable waveguide adapted for electromagnetic field induction when brought into proximity with the electrical field.

3. The apparatus of either of claims 1 or 2, wherein the analogue discriminator comprises low-power logic circuitry along with resistive and capacitive elements to form a voltage comparator which, when the magnitude of the electrical field induced in the detection antenna module exceeds the predetermined value, an activation input of the microcontroller is pulled to a high state.

4. The apparatus of claim 3, wherein the low-power logic circuitry comprises two inverters with resistive and capacitive elements that are arranged as a voltage comparator with the antenna module.

5. The apparatus of any of claims 1 to 4, wherein the microcontroller is configured with an ultra-low power sleep mode and only activated once the magnitude of the electrical field exceeds a predetermined value in order to reduce energy consumption .

6. The apparatus of any of claims 1 to 6, wherein the frequency discriminator comprises a digital filter configured within the microcontroller, so that said frequency discriminator only discriminates the frequency of the electrical field when the microcontroller is active in order to reduce energy consumption.

7. The apparatus of claim 6, wherein the digital filter of the frequency discriminator comprises a bandpass filter.

8. The apparatus of any of claims 1 to 7, wherein the predetermined frequency range within which the microcontroller actuates the notifier and transmission module is between 45Hz to 65Hz.

9. The apparatus of any of claims 1 to 8, wherein the predetermined frequency range is between 50Hz and 60Hz.

10. The apparatus of any of claims 1 to 9, wherein the audible notifier comprises a piezo transducer or speaker.

11. The apparatus of any of claims 1 to 10, wherein the visual notifier comprises a light emitting diode (LED).

12. The apparatus of any of claims 1 to 11, wherein the microcontroller is configured to actuate the notifier at a particular intensity according to a magnitude of the detected electrical field.

13. The apparatus of any of claims 1 to 12, wherein the transmission module comprises a Bluetooth Low Energy (BLE) module.

14. The apparatus of any of claims 1 to 13, wherein the notification signal is transmitted to a mobile phone handset or tablet configured with a suitable application or app which logs a geographical location (via a handset global navigation satellite system or GNSS sensor of the handset/tablet) of the handset and the magnitude and/or frequency of the detected electrical field.

15. The apparatus of any of claims 1 to 14, which includes a housing wherein the antenna, microcontroller, notifier, transmission module and discriminators are housed.

16. The apparatus of claim 15, wherein the housing includes an abutment portion for operatively abutting against a conductor, the microcontroller configured to calculate a voltage magnitude of the detected electrical field as a distance between the conductor and abutment portion is predetermined and known.

17. The apparatus of either of claims 15 or 16, wherein the housing defines a mount for operatively mounting to an insulation stick with which the abutment portion is able to be brought into abutment with a conductor.

18. The apparatus of either of claims 15 or 16, wherein the housing defines a mount and/or is suitably configured to mount to a tool, a piece of equipment and/or an article of clothing to alert a user of dangerous electrical fields when using, operating or wearing such tool, piece of equipment or article of clothing, respectively.

19. The apparatus of any of claims 1 to 18, which includes energising means for electrically energising the microcontroller, notifier, transmission module and discriminators, as required.

20. A voltage detection method comprising the step of: detecting, via a detection antenna module, an electrical field via electrical induction; discriminating, via an analogue discriminator, a magnitude of the electrical field; if the magnitude of the electrical field exceeds a predetermined value, activating a microcontroller configured with a frequency discriminator in order to discriminate a frequency of the electrical field; if the frequency of the electrical field falls within a predetermined range, actuating, via the microcontroller, an audible and/or visual notifier to notify a user and a transmission module to transmit a notification signal.

21. The method of claim 20, wherein the detection antenna module comprises a suitable waveguide adapted for electromagnetic field induction when brought into proximity with the electrical field.

22. The method of either of claims 20 or 21, wherein the analogue discriminator comprises low-power logic circuitry along with resistive and capacitive elements to form a voltage comparator which, when the magnitude of the electrical field induced in the detection antenna module exceeds the predetermined value, an activation input of the microcontroller is pulled to a high state.

23. The method of claim 22, wherein the low-power logic circuitry comprises two inverters with resistive and capacitive elements that are arranged as a voltage comparator with the antenna module.

24. The method of any of claims 20 to 23, wherein the microcontroller is configured with an ultra-low power sleep mode and only activated once the magnitude of the electrical field exceeds a predetermined value in order to reduce energy consumption .

25. The method of any of claims 20 to 24, wherein the frequency discriminator comprises a digital filter configured within the microcontroller, so that said frequency discriminator only discriminates the frequency of the electrical field when the microcontroller is active in order to reduce energy consumption.

26. The method of claim 25, wherein the digital filter of the frequency discriminator comprises a bandpass filter.

27. The method of any of claims 20 to 26, wherein the predetermined frequency range within which the microcontroller actuates the notifier and transmission module is between 45Hz to 65Hz.

28. The method of any of claims 20 to 27, wherein the predetermined frequency range is between 50Hz and 60Hz.

29. The method of any of claims 20 to 28, wherein the audible notifier comprises a piezo transducer or speaker.

30. The method of any of claims 20 to 29, wherein the visual notifier comprises a light emitting diode (LED).

31. The method of any of claims 20 to 30, wherein the microcontroller is configured to actuate the notifier at a particular intensity according to a magnitude of the detected electrical field.

32. The method of any of claims 20 to 31, wherein the transmission module comprises a Bluetooth Low Energy (BLE) module.

33. The method of any of claims 20 to 32, which includes the step of calculating, via the microcontroller, a voltage magnitude of the detected electrical field if the detection antenna module is brought within a known distance of a conductor.