Patent Application
20220178974
The present invention relates to voltage monitoring. More particularly, but not exclusively, the present invention relates to a voltage indicator suitable for use in industrial environments and other applications where power monitoring is desired.
Various voltage indicator devices and associated circuitry exist. Generally, the purpose of a voltage indicator is to visually communicate the presence or absence of voltage to trained individuals and thereby improve safety. Despite the benefits of using voltage indicators, what is needed are new and improved voltage indicators and associated circuitry.
Therefore, it is a primary object, feature, or advantage of the present invention to improve over the state of the art.
It is a further object, feature, or advantage of the present invention to provide a voltage indicator which may have a small form factor.
It is a still further object, feature, or advantage of the present invention to provide a voltage indicator with stable performance even when used at altitude or in low temperature environments.
Another object, feature, or advantage is to provide a voltage indicator which can accommodate a wide range of voltages.
Yet another object, feature, or advantage is to provide a voltage indicator device or circuit which can be incorporated into a voltage test point.
A still further object, feature, or advantage is to provide a circuit for a voltage indicator which may be adapted for monitoring a single phase or multiple phases.
A further object, feature, or advantage is to provide a circuit which may be used for monitoring AC voltages or DC voltages.
A still further object, feature, or advantage is to provide for a circuit which allows visual indicators to be provided remote from a circuit of a voltage indicator so that the circuit for the voltage indicator device may be mounted within an enclosure and the visual indicators may be viewable from outside of the enclosure.
Another object, feature, or advantage is to provide a voltage indicator which does not require an independent power source such as a battery.
One or more of these and/or other objects, features, or advantages of the present invention will become apparent from the specification and claims that follow. No single embodiment need provide each and every object, feature, or advantage. Different embodiments may have different objects, features, or advantages. Therefore, the present invention is not to be limited to or by any objects, features, or advantages stated herein.
According to one aspect, an electrical safety monitoring device includes a first set of digital switches for each of a plurality of line inputs wherein each of the first set of digital switches is configured to switch between a first state when there is a positive voltage present on a corresponding one of the plurality of line inputs and a second state when there is no voltage present on the corresponding one of the plurality of line inputs. There is also a second set of digital switches for each of the plurality of line inputs wherein each of the second set of digital switches is configured to switch between a first state when there is a negative voltage present on a corresponding one of the plurality of line inputs and a second state when there is no voltage present on the corresponding one of the plurality of line inputs. The electrical safety monitoring device further includes a first set of visual indicators, wherein each of the first set of visual indicators is electrically connected to one of the first set of digital switches and a second set of visual indicators, wherein each of the second set of visual indicators is electrically connected to one of the second set of digital switches. There is a first voltage-controlled oscillator operatively connected to the first set of digital switches for controlling a flash rate of the first set of visual indicators when the positive voltage is present above a first threshold level and a second voltage-controlled oscillator operatively connected to the second set of digital switches for controlling a flash rate of the second plurality of visual indicators when a magnitude of the negative voltage is present above a second threshold level. The threshold levels may both be below 20 volts.
The plurality of line inputs may be a single phase with a first line input and a ground input. The plurality of inputs may include a L1 input, a L2 input, a L3 input, and a ground input and the electrical safety monitoring device may provide for three-phase voltage monitoring. The plurality of line inputs may include a L1 input, a L2 input, a L3 input, a ground input, and a neutral input.
The first voltage-controlled oscillator may be configured such that a higher magnitude of positive voltage present on one of the plurality of line inputs results in a higher flash rate for the one of the plurality of line inputs with the positive voltage present. The second voltage-controlled oscillator may be configured such that a higher magnitude of negative voltage present on one of the plurality line inputs results in a higher flash rate for the one of the plurality of line inputs with the negative voltage present.
Each of the visual indicators may be a light emitting diode. The device may further include a power supply circuit and a power storage circuit operatively connected to the power supply circuit. The device may further include a test point for each of the line inputs.
The device may further include a body and the first set of digital switches, the second set of digital switches, the first voltage-controlled oscillator, and the second voltage-controlled oscillator may be disposed within the body and the first set of visual indicators and the second set of visual indicators may be mounted at a face of the electrical safety monitoring device. Each of the first set of visual indicators and the second set of visual indicators may be labeled on the face. The device may further include a test point for each of the line inputs, the test point for each of the line inputs accessible on the face. The face may be circular and may be partitioned into equal regions for each of the line inputs.
According to another aspect, light tubes such as fiber optics may be used to convey light from one or more LEDs or other visual indicators to a remote location such as to a remotely mounted head unit.
According to another aspect, an electrical safety monitoring device is provided which may include a first set of digital switches for each of a plurality of line inputs wherein each of the first set of digital switches is configured to switch between an on state and an off state based on magnitude of positive voltage on a corresponding one of the plurality of line inputs and a second set of digital switches for each of the plurality of line inputs wherein each of the second set of digital switches is configured to switch between an on state and an off state based on magnitude of negative voltage on a corresponding one of the plurality of line inputs. It may further include a first set of LEDs, wherein each of the first set of LEDs is electrically connected to one of the first set of digital switches and a second set of LEDs, wherein each of the second set of LEDs is electrically connected to one of the second set of digital switches. The device may further include a first voltage-controlled oscillator operatively connected to the first set of digital switches for controlling a flash rate of the first set of LEDs when the positive voltage is present above a first threshold level and a second voltage-controlled oscillator operatively connected to the second set of digital switches for controlling a flash rate of the second plurality of LEDs when a magnitude of the negative voltage is present above a second threshold level. The device may further include a body wherein the first set of digital switches, the second set of digital switches, the first voltage-controlled oscillator, and the second voltage-controlled oscillator are disposed within the body and wherein the first set of LEDs and the second set of LEDs are mounted at a face of the electrical safety monitoring device. The device may further include a test point for each of the line inputs, the test point for each of the line inputs accessible on the face.
Illustrated embodiments of the disclosure are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein.
In the context of the circuit shown in
As shown in
A three-phase power supply circuit 14 and power storage circuit 16 are shown. The three-phase power supply circuit 14 may provide for rectifying power from the line inputs L1, L2, L3, GND. Diodes D9, D10 are shown on the output side of the rectifiers. Resistors R5, R6, R7, R8 are shown as well as transistors Q1, Q6. The power storage circuit 16 allows for temporarily storing charge from the three-phase power supply circuit to provide appropriate inputs to the voltage-controlled oscillators 18A, 18B. Capacitors C1, C2, C7, C8 are shown along with diodes D11, D12, and resistors R9, R10. The capacitors provide for storing charge.
As the voltage inputs to the voltage-controlled oscillators 18A, 18B increase in magnitude, the rate of flashing of the corresponding visual indicators also increases, provided that the corresponding digital switches are turned on. When the voltage of one or more of the line inputs is above a threshold voltage then a corresponding digital switch is turned on and the corresponding visual indicator flashes at a frequency set by the corresponding voltage-controlled oscillator.
Note that only two voltage-controlled oscillators 18A, 18B are used in the circuit 10 of
There is a first set of digital switches 22A with each digital switch associated within the set of digital switches 22A is used to switch on a corresponding visual indicator within the set 20A these visual indicators are to indicate the presence of a positive voltage. There is a second set of digital switches 22B with digital switch used to switch on a corresponding visual indicator within the set 20B. The circuit for the first set of digital switches includes resistor R21, R23, transistor Q7-A (for the first switch), resistors R25, R27, and transistor Q8-A (for the second switch), resistors R29, R31, transistor Q9-A (for the third switch), resistors R33, R35 and transistor Q10-A (for the fourth switch). For the second set of digital switches, the switches includes resistors R22, R24, transistor Q7-B (for the first switch), resistors R26, R28, transistor Q8-B (for the second switch), resistors R30, R32, transistor Q9-B (for the third switch), resistors R34, R36, transistor Q10-B (for the fourth switch). Bypass Capacitors C11, C3, C12, C4, C13, C9, C14, C10 are also shown. Although transistor switching is shown, other types of digital switching may be performed if desired. For example, a microcontroller may be used to perform digital switching. Thus, the digital switches may form a part of the microcontroller and need not be separate devices. Where a microcontroller is used, the microcontroller may also perform the functionality of the voltage-controlled oscillators.
The visual indicators may be in the form of light emitting diodes and there may be a first set of visual indicators 20A: LED L1+, LED L2+, LED L3+, LED G+ for indicating positive voltages associated with each of the line inputs and a second set of visual indicators 20B: LED L1−, LED L2−, LED L3−, LED G− for indicating negative voltages associated with each of the line inputs.
Although a three-phase power connection is shown as is typically used for AC power lines, the circuit may be modified to accommodate other types of power connectors. For example, instead of a three-phase power connection, a single-phase power connection may be monitored in which case there would need only be two power line inputs. Similarly, a five-wire power connection may be used which include a first line input, a second line input, a third line input, a ground, and a neutral connection. Of course, the circuit may be modified to add additional line inputs by adding the appropriate visual indicators, digital switches, power sense diodes, and/or other circuitry. It is also to be understood that the circuit may also be used for DC voltage lines as well as AC voltage lines and thus the same circuit may be used in a wide range of applications and environments.
The circuitry shown and described may be manufactured and design with solid state circuitry with components with military grade tolerances. This assists in providing various advantages including the ability to use a small form factor and to assist in maintaining stability of the device including at altitude or in low temperature environments. The circuit shown may also be advantageous over some prior art devices in that it accommodates a wide range of voltages. For example, the component values may be selected to allow for an absolute value of under 20 volts to activate an LED and to stay activated up to an absolute value of over 3000 volts. It is to be understood different lower thresholds may be used depending upon the particular application and different higher thresholds may be used depending upon the particular application. It is also to be understood that the voltage-controlled oscillator may be configured such that once a threshold voltage is met, the flash rate either maintains at a constant frequency or else the visual indicator is maintained in an on-state. Thus, at a certain voltage level a corresponding visual indicator or LED may stay on continuously while at a lower absolute voltage level the corresponding visual indicator or LED may flash. In other words, if the voltage on a line input is above a particular threshold the visual indicator or LED may be continuously lit without flashing. If the voltage on the line input is present but drops below the particular threshold then the visual indicator or LED will flash.
Thus, different effects may be obtained depending on the threshold. In one example a relatively low threshold may be set and when the voltage present is above the low threshold, the corresponding visual indicator may be continuously lit or on. If below the threshold, the corresponding visual indicator may flash. Thus, an operator would know that a lower voltage is present if the visual indicator is flashing. The flash rate provides a further indicator of the voltage present with a higher flash rate indicative of a higher voltage but still below the threshold voltage.
In another example, a higher threshold may be set so that over a relatively wide range of voltages, if a voltage is present but less than the higher threshold, the corresponding visual indicator flashes at a flash rate indicative of the voltage present. In this example, the operator may be more concerned about the flash rate, as the higher threshold may be set at a level that is not frequently met. Of course, if the visual indicator is continuously on, that higher threshold has been met.
The line inputs may carry DC voltage instead of AC voltages. Where a positive DC voltage is present on a line input, the corresponding LED will be flash or be lit. Similarly, where a negative DC voltage is present on a line input, the corresponding LED will flash or be lit.
The electrical safety monitoring device shown and described herein is well-suited to the industrial environment such as to mount to panels or doors of electrical enclosures or elsewhere. It is to be understood, however, that the electrical safety monitoring device may be used elsewhere such as in homes, on solar panels, or wherever else voltage monitoring is necessary or desired. It is to be understood that the size, configuration, and number of line inputs may vary based on the specific application.
The invention is not to be limited to the particular embodiments described herein. In particular, the invention contemplates numerous variations in the particular components used, component values, voltage ranges, types of visual indicators, threshold values, device shapes and geometries, and other variations, options, and alternatives. The foregoing description has been presented for purposes of illustration and description. It is not intended to be an exhaustive list or limit any of the invention to the precise forms disclosed. It is contemplated that other alternatives or exemplary aspects are considered included in the invention. The description is merely examples of embodiments, processes, or methods of the invention. It is understood that any other modifications, substitutions, and/or additions can be made, which are within the intended spirit and scope of the invention.
