NL2020795B1

NL2020795B1 - Voltage tester

Info

Publication number: NL2020795B1
Application number: NL2020795A
Authority: NL
Inventors: Lambertus Bernardus Krabbe Johannes
Original assignee: Krabbe Electronics
Priority date: 2018-04-19
Filing date: 2018-04-19
Publication date: 2019-10-28

Abstract

The present disclosure related to a voltage tester, comprising: - a housing; 5 - an electrically conductive probe protruding from the housing; - a resistor disposed inside the housing and electrically connected to the electrically conductive probe; - at least one light emitting diode, LED, lighting unit disposed inside the housing and comprising at least one LED, said lighting unit being electrically connected With the resistor and 10 the probe; and - at least one conductive element disposed on an outer surface of the housing and extending on a surface portion thereof so that it may be easily touched by an operator forming an electric connection, said conductive element being electrically connected With at least one of the resistor and the LED lighting unit.

Description

G01R 19/14 (2018.01) G01R 19/155 (2019.01) G01R

1/067 (2019.01) G01R 19/165 (2019.01) (© Afsplitsing van aanvraag , ingediend (30) Voorrang:

Q Aanvraag ingeschreven: 28 oktober 2019 (43) Aanvraag gepubliceerd:

oktober 2019 © Octrooischrift uitgegeven:

oktober 2019 © Octrooihouder(s):

Krabbe Electronics te ENSCHEDE © Uitvinder(s):

Johannes Lambertus Bernardus Krabbe te Enschede © Gemachtigde:

Ir. P.J. Hylarides c.s. te Den Haag (54) VOLTAGE TESTER (57) The present disclosure related to a voltage tester, comprising:

- a housing;

- an electrically conductive probe protruding from the housing;

- a resistor disposed inside the housing and electrically connected to the electrically conductive probe;

- at least one light emitting diode, LED, lighting unit disposed inside the housing and comprising at least one LED, said lighting unit being electrically connected with the resistor and the probe; and

- at least one conductive element disposed on an outer surface of the housing and extending on a surface portion thereof so that it may be easily touched by an operator forming an electric connection, said conductive element being electrically connected with at least one of the resistor and the LED lighting unit.

NL B1 2020795

Dit octrooi is verleend ongeacht het bijgevoegde resultaat van het onderzoek naar de stand van de techniek en schriftelijke opinie. Het octrooischrift komt overeen met de oorspronkelijk ingediende stukken.

VOLTAGE TESTER

The present disclosure relates to a voltage tester, also known as a test light, test lamp or mains tester, for determining the presence or absence of an electric voltage.

Voltage testers are known. An objective of the present disclosure is to provide a voltage tester that is an improvement over known voltage testers having at least a probe and a light source. Voltage testers should light up very brightly to clearly indicate a detected voltage, even in bright daylight. However, current passing through a light source should preferably be sufficiently low to allow omission of a grounding contact, which complicates handling in the field of many prior art voltage testers.

Said objective is achieved with a voltage tester according to the present disclosure, comprising a housing; an electrically conductive probe protruding from the housing; a resistor disposed inside the housing and electrically connected to the electrically conductive probe; at least one light emitting diode (LED) lighting unit disposed inside the housing and comprising at least one LED, said lighting unit being electrically connected with the resistor and the probe; and at least one conductive element disposed on an outer surface of the housing and extending on a surface portion thereof, so that it may easily be touched by an operator to form an electric connection to a ground, said conductive element being electrically connected with at least one of the resistor and the LED lighting unit.

In some embodiments of the present disclosure, the LED lighting unit may comprise a plurality of LEDs.

In additional or alternative embodiments of the present disclosure, the plurality of LEDs of the LED lighting unit may comprise a structure of miniaturised, densely packed LEDs. Said structure may be being configured to optimize a short-term light output of the LED lighting unit, rather than a long-term dissipation of heat of the LED lighting unit.

In further additional and/or alternative embodiments of the present disclosure, the plurality of LEDs of the LED lighting unit may comprise at least two groups of LEDs. Said groups of LEDs may each comprise at least one LED, wherein each group of LEDs is connected in anti-parallel the one with the other, hi these embodiments, the LEDs of either one of the group of LEDs may emit light at a given point in time while the other does not, depending on a polarity of the voltage of which the presence is to be determined. This advantageously allows a polarity of the voltage to be determined.

In further additional and/or alternative embodiments of the present disclosure, each group of LEDs of the at least two groups of LEDS may comprise LEDs with a specific colour, allowing a quick and easy determination of whether or not a given group of LEDs is emitting light indicating a presence of a voltage with a specific polarity.

hi further additional and/or alternative embodiments of the present disclosure, the colours of the LEDs of the at least two groups of LEDS may be highly contrasting colours, such as red and green or yellow and blue. This too allows for quick and easy determining which group of LEDs is emitting light indicating a presence of a voltage with a specific polarity, lessening the possibly of errors by an operator while usage of the voltage tester.

In further additional and/or alternative embodiments of the present disclosure, the material of the housing may comprise a clear, transparent or translucent material, preferably a colourless material. This too allow for a quick and easy determining which group of LEDs is emitting light, indicating a presence of a voltage with a specific polarity.

In further additional and/or alternative embodiments of the present disclosure, the resistor may be configured to limit an electric current to such a degree, that said electric current may safely flow through the body of an operator without a risk of injury or discomfort, when the probe is electrically connected to a main of a building and the operator touches the conductive element.

In additional and/or alternative embodiments of the present disclosure, the at least one LED of the LED lighting unit may be adjusted to have at least one of its maximum light yield and expected lifetime at an operating current that coincides with a maximum current with respect to a predetermined voltage, said maximum current being determined by the magnitude of the electric resistance of the resistor.

In the following description, preferred embodiments of the present disclosure are further elucidated with reference to the drawing, in which:

Fig. I shows a first exemplary embodiment of the present disclosure;

Fig. 2 shows an alternative embodiment of the present disclosure, wherein a lighting unit of the voltage tester comprises a plurality of LEDs;

Fig. 3 shows another alternative embodiment of the present disclosure, wherein a lighting unit of the voltage tester comprises two groups of LEDs;

Fig. 4 shows an alternative embodiment of the present disclosure for the embodiment of Fig. 3, wherein a lighting unit of the voltage tester comprises a plurality of groups of LEDs

Fig. 5A-C show exemplary graphs of voltages of which a presence may be determined with a voltage tester according to the present disclosure.

Fig. 1 shows a voltage tester 1 according to an exemplary first embodiment of the present disclosure. Voltage tester 1 comprises a housing 2 with an electrically conductive probe 3 protruding therefrom on one end thereof, a resistor 4 and a lighting unit comprising light emitting diode (LED) 5 disposed in the housing and a conductive element 6 disposed on an outer surface of the housing.

For safety reasons, housing 2 is preferably made of a non-conductive material. In some embodiments of the disclosure, housing 2 may be made of a clear, translucent or transparent material, such as a clear, colourless polymer, which may aid an operator of voltage tester 1 with determining whether LED 5 is emitting light.

Electrically conductive probe 3 protrudes from an inside of housing 2 outwards to an outside of housing 2. In the embodiment depicted in Fig. 1, probe 3 is electrically connected in series to LED 5 via resistor 4. The connection of resistor 4 to LED 5 may be via either one of a cathode or an anode of LED 5. Alternatively, and in contrast to Fig. 1, LED 5 may be connected to probe 3 directly via either its cathode or its anode, with resistor 4 being connected to the other one of its cathode or its anode.

In the exemplary embodiment depicted in Fig. 1, conductive element 6 is electrically connected to LED 5 and disposed on or in an outer surface of housing 2. In preferred embodiments of the present disclosure, conductive element 6 extends over a surface portion of housing 6, said surface portion being sufficiently large to be touched by an operator of voltage tester 1 during usage thereof.

During usage of voltage tester I, an operator of voltage tester 1 places probe 3 in direct electrical contact with a voltage source of which the presence of a voltage is to be determined, such as a mains electricity of a building. The operator then connects conductive element 6 to a ground (earth) reference, for example by touching conductive element 6. When conductive element 6 is connected to the ground reference, an electric current will flow from the voltage source, through probe 3, resistor 4, LED 5 and conductive element 6 to the ground. During this process, LED 5 will emit light, thus indicating the presence of an electric voltage at the voltage source. Alternatively, LED 5 will not emit light, thus indicating an absence of a voltage at the voltage source.

When the operator connects to voltage tester 1 by touching conductive element 6, the resulting electric current may flow through the body of the operator. As such, resistor 4 preferably comprises a resistance value that is sufficiently large to limit a magnitude of the resulting electric current to a degree wherein there is no risk at bodily harm or discomfort for the operator, such as a resistance value of approximately 1 ΜΩ or more. For example, the resulting electric current may have a magnitude of approximately 0.02 mA - 0.12 mA that is determined by the resistance value of resistor 4. Consequently, LED 5 is preferably configured to function at this preferred safe current, having at least one of its maximum light yield and expected lifetime at said current.

Fig. 2 shows an alternative exemplary embodiment of the disclosure, wherein the lighting unit comprises a plurality of LEDs 5a, 5b and 5c, for example in an array on a single substrate. Housing 2 is not shown in Fig. 2 for the purpose of clarity. In this embodiment of the disclosure, light is emitted by each one of LEDs 5a, 5b and 5c when a voltage is determined to be present, thus resulting in a more easily identifiable presence of an electric voltage at the voltage source. Preferred embodiments of the disclosure may comprise an even greater number of LEDs disposed in the lighting unit in housing 2. In some of these embodiments, the LEDs may comprise a structure of miniaturised LEDs that are densely packed on a relatively small surface of preferably a single substrate, for example a LED bar, to optimize the output of light upon determining a voltage to be present. Application of such a structure is made possible due to fact that, in everyday practice, determining a presence of a voltage with voltage tester 1 is a relatively short process that may be completed in a time frame of a few seconds. Therefore, the generation and dissipation of heat by said plurality of densely packed LEDs is not considered to be an issue of importance, allowing the plurality of LEDs to be densely packed in said structure.

In some embodiments of the present disclosure, LEDs of a specific colour that can be easily distinguished from their surroundings may be used, allowing for a more easily identifiable presence of a voltage.

Fig. 3 shows yet another alternative exemplary embodiment of the present disclosure, wherein the lighting unit also comprises a plurality of LEDs 5a, 5b, 5c, 5d, 5e, and 5f. Said plurality of LEDs comprises LEDs distributed over at least two groups of LEDS, wherein the first group of LEDs comprises LEDs 5a, 5b, and 5c of for example a LED bar and the second group of LEDs comprises LEDs 5d, 5e and 5f. In Fig. 3, of for example a second LED bar, wherein the two groups of LEDs forming the lighting unit are connected in anti-parallel to one another and the lighting unit comprising the LEDs is connected to probe 3 via resistor 4 and to conductive element

6. Alternatively, each group of LEDs may also comprise a single LED or more than the number of LEDs depicted in Fig. 3.

The voltage tester 1 according to the exemplary embodiment depicted in Fig. 3 advantageously allows an operator to easily determine the presence of a voltage, due to a high brightness of light emitted by the light source(s) at a very low current, which may even be discharged through an operator’s body acting as a ground, regardless of a polarity of said voltage or whether said voltage is a direct current (DC) voltage with a specific polarity or an alternating current (AC) voltage.

Fig. 4 shows yet another alternative exemplary embodiment of the present disclosure, wherein the lighting unit also comprises a plurality of LEDs in two groups 5a, 5d; and 5c, 5f. Said plurality of LEDs comprises LEDs distributed over at least two groups of LEDS, wherein the first group of LEDs comprises LEDs 5a and 5d arranged in a parallel configuration, and LED’s 5c and 5f in a parallel configuration. The first group 5a, 5d is arranged in series with the second group 5c, 5f. More of such groups 5a, 5d; 5c, 5f may be provided (as indicated with the dotted line 10 in figure 4), and each branch may comprise more than one LED.

In Fig. 4, the LEDs in each of the two shown groups of LEDs forming the lighting unit are connected in anti-parallel to one another and the lighting unit comprising the LEDs is connected to probe 3 via resistor 4 and to conductive element 6. Alternatively, each group of LEDs may also comprise a single LED or more than the number of LEDs depicted in Fig. 4.

The voltage tester 1 according to the exemplary embodiment depicted in Fig. 4 advantageously allows an operator to easily determine the presence of a voltage, due to a high brightness of light emitted by the light source/s) at a very low current, which may even be discharged through an operator’s body acting as a ground, regardless of a polarity of said voltage or whether said voltage is a direct current (DC) voltage with a specific polarity or an alternating current (AC) voltage.

The workings of the embodiment depicted in Fig.’s 3 and 4 will be further elucidated with reference to Fig. 5 A - C, under reference to the configuration of Fig. 3, but the workings of the configuration of Fig. 4 is essentially the same or at least similar.

Fig. 5A shows a graph of an exemplary voltage 7 of a voltage source of which the presence may be determined with voltage tester 1. As is illustrated in Fig. 5A, voltage 7 is a DC current voltage with a positive polarity with respect to a ground voltage. When the presence of voltage 7 is determined by an operator using voltage tester 1, probe 3 is placed in direct electrical contact with the voltage source of which voltage 7 stems from by the operator, and the operator completes the electric circuit by connecting conductive element 6 to a ground reference, for example by physically touching conductive element 6.

Upon completion of the circuit, an electric current will flow from the voltage source, through resistor 4, through the first group of LEDS comprising EEDs 5a, 5b and 5c to grounded conductive element 6. Because EEDs 5a, 5b and 5c are arranged to have their respective forward directions to coincide with the direction of the current resulting from voltage 7, the current resulting from voltage 7 will flow through EEDs 5a, 5b and 5c, causing these EEDs to emit light and thus indicate the presence of voltage 7. In contrast to the first group comprising EEDs 5a, 5b and 5c, EEDs 5d, 5e and 5f comprised by the second group of LEDs are arranged so that their respective reverse directions coincide with the direction of the current resulting from voltage 7. As a consequence, no current will pass through LEDs 5d, 5e and 5f to cause these respective LEDs to emit light.

Fig. 5B shows a graph of another exemplary voltage 8 of a voltage source of which the presence may be determined with voltage tester 1. As is shown in Fig. 5B, voltage 8 is a DC current voltage with a negative polarity with respect to a ground reference. When voltage tester 1 is used to determine the presence of voltage 8, electric current will through resistor 4, through LEDs 5d, 5e and 5f through grounded conductive element 6. In this case, LEDs 5d, 5e and 5f are arranged to have their respective forward directions to coincide with the direction of the current resulting from voltage 8. Thus, the current resulting from voltage 8 will flow through LEDs 5d, 5e and 5f, causing these LEDs to emit light and thus indicate the presence of voltage 8. In contrast to LEDs 5d, 5e and 5f, the reverse directions of LEDs 5a, 5b and 5c are arranged to coincide with the direction of the current caused by the presence of voltage 8. Therefore, no current will flow through LEDs 5a, 5b and 5c and these LEDs will not emit light.

The embodiments of the present disclosure as depicted in Fig.’s 3 and 4 therefore allows for an operator to determine the presence of a DC voltage regardless of the polarity of said voltage is positive or negative with respect to a ground reference, as in both cases either LEDs 5a, 5b, 5c of the first group of LEDs or LEDs 5d, 5e and 5f of the second group of LEDs will emit light when a voltage is present.

To more easily determine whether the group of LEDs that is emitting light is the first group of LEDs or the second group of LEDs, and therefore whether the detected voltage has a positive or a negative polarity with respect to a ground reference, the LEDs of the first group of LEDs may be of a colour that is different from the LEDs of the second group of LEDs. For example, the LEDs comprised by the first group of LEDs may be green LEDs, while the LEDs comprised by the second group of LEDs may be red LEDs. Preferably, highly contrasting colours are used, such as red and green or yellow and blue.

Fig. 5C shows a graph of an other exemplary voltage 9 of a voltage source of which the presence may be determined with the voltage tester 1 according to the present disclosure. In contrast to Fig. 5A-B, which depict graphs of DC voltages, Fig. 5C depicts a graph of an AC voltage of which the presence may be determined using voltage tester 1. Upon placing probe 3 in direct electrical contact with an AC voltage source of which an AC voltage is to determined, an alternating current will flow through resistor 4 and alternately through LEDs 5a, 5b and 5c comprised by the first group of LEDs and LEDs 5d, 5e and 5f comprised by the second group of LEDs. When the frequency of the AC voltage of which the presence to be determined is relatively low, LEDs 5a, 5b and 5c of the first group of LEDs and LEDs 5d, 5e and 5f of the second group of LEDs will therefore alternately emit light, thus indicating the presence of an AC voltage at the voltage source. Alternatively, when the frequency of the AC voltage to be determined is relatively high, LEDs 5a, 5b and 5c of the first group of LEDs and LEDs 5d, 5e and 5f of the second group of LEDs may emit light simultaneously, because each LED may not stop emitting light immediately after it stops conducting a current or because the alternation frequency is so high that it may appear that the LEDs of the two groups of LEDs are emitting light simultaneously. The simultaneous emission of light by all LEDs is - like the alternating emission of light by the two groups of LEDS - considered to indicate a presence of an AC voltage.

It is hereby noted that the above exemplary descriptions of embodiments and accompanying figures should by no means be considered to be considered limiting. Many alternative or additional embodiments may be conceived by the skilled person, all of which must be considered embodiments of the presently disclosed disclosure. Instead, the scope for which protection is sought is defined in the appended claims of the present disclosure.

Claims

CONCLUSIONS

A voltage finder for determining the presence or absence of an electrical voltage, comprising:

- a housing;

- an electrically conductive probe protruding from the housing;

- a resistor arranged in the housing and electrically connected to the electrically conductive probe;

- at least one light-emitting diode, LED, light unit mounted in the housing and comprising at least one LED, said light unit being electrically connected to the resistor and the probe; and

- at least one conductive element, which is arranged on an outer surface of the housing and extends over a surface part thereof, so that it can easily be touched by a user to form an electrical connection to an earth, said conductive element being electrically connected with at least one of the resistor and the LED light unit.

The voltage finder according to claim 1, wherein the LED light unit comprises a number of LEDs.

The voltage finder according to claim 2, wherein the number of LEDs of the LED light unit comprises a structure of miniaturized, closely packed LEDs, said structure being adapted to optimize a short-term light output instead of a long-term dissipation of heat from the LED light unit.

The voltage finder according to claim 2 or 3, wherein the number of LEDs of the LED light unit comprises at least two groups of LEDs, said groups of LEDs each comprising at least one LED, each said group of LEDs being antiparallel to the other.

The voltage finder according to claim 4, wherein each group of LEDs of the at least two groups of LEDs comprises LEDs of a specific color.

The voltage finder according to claim 5, wherein the colors of the LEDs of the at least two groups of LEDs are highly contrasting colors, such as red and green.

A voltage locator according to any of the preceding claims, wherein the material of the housing comprises a clear, transparent or translucent material.

A voltage locator according to any of the preceding claims, wherein the resistor is adapted to limit an electric current such that said electric current can flow safely through the body of a user, without risk of injury or discomfort when the probe is electrically is connected to the electricity grid of a building.

A voltage finder according to any of the preceding claims, wherein at least one LED of the LED light unit is arranged to include at least one of its maximum light output and expected lifetime at an operating current coinciding with a maximum current with respect to a pre-current certain voltage, wherein said maximum

The current is determined by the magnitude of the electrical resistance of the resistor.

1/2

5b

Hl