WO2025073043A1

WO2025073043A1 - Power distribution box

Info

Publication number: WO2025073043A1
Application number: PCT/CA2024/051303
Authority: WO
Inventors: Petar GUEORGUIEV; Simon ARCHAMBAULT; William Awad
Original assignee: Vita Detection Inc
Current assignee: Vita Detection Inc
Priority date: 2023-10-02
Filing date: 2024-10-01
Publication date: 2025-04-10
Anticipated expiration: 2026-04-02

Abstract

A circuit for power distribution in an x-ray scanning device includes a transformer having at least two primary windings at a first side thereof and at least two secondary windings at a second side thereof. The at least two secondary windings are connected in series for distributing power in a first voltage range to at least one x-ray scanning device component. A controller receives AC input in one of the first voltage range and a second voltage range that is approximately half of the first voltage range. The controller is configured to connect the at least two primary windings with one another in series circuit when AC input is received in the first voltage range and to connect the at least two primary windings with one another in parallel circuit when AC input is received in the second voltage range for energizing the at least one x-ray scanning device component.

Description

POWER DISTRIBUTION BOX

[0001] The present invention relates to power distribution boxes. More specifically, the present invention relates to power distribution boxes which distribute electrical power supply from a power grid to internal components of an x-ray scanning device.

BACKGROUND

[0002] Modern electronic computing devices, ranging from personal computers and laptops to servers and data centers, rely on a consistent and safe supply of electrical power. The power delivery infrastructure that bridges the gap between a power grid of a building and the internal components of a computing device is conducive not only for efficient device functionality but also for user safety and equipment longevity.

[0003] Traditionally, buildings are connected to an external power grid, which supplies alternating current (AC) at voltages standardized by region (e.g., 120V/60Hz and 220-240V/60Hz split phase in North America and 220- 240V/50Hz in Europe, Africa, Asia and Australia). Within a building, this power is distributed through circuit breakers and wiring to various electrical outlets.

[0004] Given that most electronic devices operate on direct current (DC), there is a necessity to convert the AC power from the grid to the DC power suitable for device components. This conversion is typically achieved using power converters or adapters. These converters often come with built-in surge protection and voltage regulation capabilities to protect the electronic device from power fluctuations and spikes.

[0005] In settings where multiple devices are powered simultaneously, Power Distribution Units (PDUs) are commonly used. They allow for centralized power distribution and often incorporate surge protection. For individual devices or at the consumer level, surge protectors offer an additional layer of protection by detecting and preventing voltage spikes from reaching the attached devices. [0006] Safety is paramount in power delivery. Proper grounding ensures that any unwanted electrical currents are diverted away from the user and device, reducing the risk of electrical shock and equipment damage. Circuit breakers and fuses serve as safeguards, interrupting power flow when they detect an overload or short circuit.

[0007] For electronic computing devices where continuous operation is preferred, Uninterruptible Power Supplies (UPS) are often employed. They provide battery-backed power during short-term outages or power quality issues, ensuring that the computing device continues to operate seamlessly. Some advanced UPS systems also offer power conditioning, ensuring that the power supplied to the device is free from voltage fluctuations and noise.

[0008] Efficiency in power conversion and delivery is pivotal to minimize energy wastage. As devices operate, they produce heat. Therefore, modern power supply designs also take into consideration thermal management, ensuring that the heat produced during power conversion and device operation is adequately dissipated to prevent overheating.

[0009] While significant advancements have been made in safely supplying power from a building's power grid to the internal components of electronic computing devices, there remains a need for further improvements in safety, efficiency, and reliability.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0010] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0011] FIG. 1 is a diagram representing a power distribution box according to one aspect;

[0012] FIG. 2 is a diagram representing the power distribution box of FIG. 1 , according to one aspect; [0013] FIG. 3 is a block diagram representing the power distribution box, according to one aspect;

[0014] FIG. 4 is a block diagram representing a power control board, according to one aspect;

[0015] FIG. 5 is a block diagram representing firmware, according to one aspect;

[0016] FIG. 6 is a diagram representing a controller, according to one aspect;

[0017] FIG. 7 is a diagram representing a LED array, according to one aspect;

[0018] FIG. 8 is a diagram representing the power distribution box, according to one aspect;

[0019] FIG. 9 is a diagram representing power control board power supply, according to one aspect;

[0020] FIG. 10 is a diagram representing a current measurement circuit, according to one aspect; and,

[0021] FIG. 11 is a diagram representing an isolated communication circuit, in accordance with one aspect;

SUMMARY

[0022] The present invention relates to power distribution boxes. More specifically, the present invention relates to power distribution boxes which distribute electrical power supply from a power grid to internal components of an x-ray scanning device.

[0023] In one aspect, there is provided a circuit for power distribution in an x- ray scanning device. The circuit includes a transformer having at least two primary windings at a first side thereof and at least two secondary windings at a second side thereof. The at least two secondary windings may be connected in series for distributing power in a first voltage range to at least one x-ray scanning device component. The circuit also includes a controller for receiving AC input in one of the first voltage range and a second voltage range that is approximately half of the first voltage range. The controller may be in electrical communication with the at least two primary windings and configured to connect the at least two primary windings with one another in series circuit when AC input is received in the first voltage range and to connect the at least two primary windings with one another in parallel circuit when AC input is received in the second voltage range for energizing the at least one x-ray scanning device component. The first voltage range may be 230VAC +/-10% and the second voltage range may be 115VAC +/-10%.

[0024] In one aspect, the controller may be part of a power control board for controlling distribution of AC input power supply to components of the x-ray scanning device. The power control board is electrically coupled with an uninterruptible power source. The uninterruptible power source may include a first power supply unit for x-ray scanning device components which have embedded AC/DC converters and a second power supply unit for x-ray scanning device components which are absent an embedded AC/DC converter.

[0025] The circuit may further include at least one x-ray scanning device component in circuit with the second side of the transformer for receiving power therefrom. An electromagnetic compliance filter may be in circuit between the second side of the transformer and the at least one x-ray scanning device component. The electromagnetic compliance filter may include at least one of a capacitor for conducting input harmonics to ground to reduce input harmonics reaching the at least one x-ray scanning device component and, a surge protector to prevent surges that succeed in passing through the transformer to the secondary side from reaching the at least one x-ray scanning device component.

[0026] When the AC input is in the first voltage range, the controller may close a first relay between the end terminal of the first primary winding and the beginning terminal of the second primary winding, may open a second relay electrically coupled with the end terminal of the first primary winding between a live AC input and a neutral line and may open a third relay electrically coupled with the beginning terminal of the second primary winding between the live AC input and the neutral line. When the AC input is in the second voltage range, the controller may open the first relay, may close the second relay and may close the third relay.

[0027] The circuit may further include a circuit breaker in circuit with the at least two primary windings of the transformer to interrupt the at least two primary windings of the transformer after the circuit breaker detects one of an overload and a short circuit. The circuit breaker may include at least two circuit breaker relays each electrically coupled with a corresponding one of the at least two primary windings of the transformer, the at least two circuit breaker relays being connected in series with one another to simultaneously interrupt the at least two primary windings after the circuit breaker detects the one of the overload and the short circuit.

[0028] The circuit may further include an AC filter for measuring AC input voltage range, wherein the controller receives the measured AC input in the first voltage range and the second voltage range.

[0029] In another aspect, there is provided a method for power distribution in an x-ray scanning device, including the steps of energizing, via AC input, a circuit having a controller; receiving, at the controller, AC input in one of a first voltage range and a second voltage range that is approximately half of the first voltage range, the controller in electrical communication with a transformer having at least two primary windings at a first side thereof and at least two secondary windings at a second side thereof, the at least two secondary windings connected in series for distributing power in the first voltage range to at least one component of the x-ray scanning device; connecting the at least two primary windings with one another in series circuit when AC input is received in the first voltage range and connecting the at least two primary windings with one another in parallel circuit when AC input is received in the second voltage range; and, distributing power from the second side of the transformer in the first voltage range to energize at least one x-ray scanning device component. The first voltage range may be 230VAC +/-10% and the second voltage range may be 115VAC +/-10%.

[0030] The method may further include the steps of when the AC input is in the first voltage range, via the controller, closing a first relay between the end terminal of the first primary winding and the beginning terminal of the second primary winding, opening a second relay electrically coupled with the end terminal of the first primary winding between a live AC input and a neutral line and opening a third relay electrically coupled with the beginning terminal of the second primary winding between the live AC input and the neutral line; and, when the AC input is in the second voltage range, via the controller, opening the first relay, closing the second relay and closing the third relay.

[0031] Prior to the receiving step, the method may further include the step wherein the controller automatically measures the voltage, frequency and amplitude of the AC input. The method may further include the step of interrupting, via a circuit breaker in circuit with the at least two primary windings of the transformer, the at least two primary windings of the transformer after the circuit breaker detects one of an overload and a short circuit.

[0032] The method may further include the step of at least one of conducting input harmonics to ground and preventing surges via an electromagnetic compliance filter in circuit between the second side of the transformer and the at least one x-ray scanning device component.

[0033] In another aspect, there is provided an x-ray scanning device including a transformer having at least two primary windings at a first side thereof and at least two secondary windings at a second side thereof. The at least two secondary windings are connected in series for distributing power in a first voltage range to at least one x-ray scanning device component. The device further includes a controller for receiving AC input in one of the first voltage range and a second voltage range that is approximately half of the first voltage range. The controller is in electrical communication with the at least two primary windings and configured to connect the at least two primary windings with one another in series circuit when AC input is received in the first voltage range and to connect the at least two primary windings with one another in parallel circuit when AC input is received in the second voltage range for energizing the at least one x-ray scanning device component. The transformer and the controller may be components of a power distribution system of the x-ray scanning device.

DETAILED DESCRIPTION

[0034] The present invention relates to power distribution boxes. More specifically, the present invention relates to power distribution boxes which distribute electrical power supply from a power grid to internal components of an x-ray scanning device.

[0035] In FIG. 1 , there is shown a circuit diagram 100 for a power distribution box 102. The power distribution box 102 provides consistent and clean electrical alternating current (AC) and direct current (DC) power supply from a power source, such as a power grid of a building to all internal components of an x-ray scanning device.

[0036] The power distribution box 102 may be utilized, in one aspect, with a x- ray scanning device (not shown). In the aspect described herein, the power distribution box 102 is suited for use with small to medium sized x-ray scanning devices. However, with modification to include additional high-power components, the power distribution box 102 could be used for larger x-ray scanning devices, such as those used for scanning cargo.

[0037] AC input 104, shown in FIG. 1 , provides a connection to an AC power source (not shown), such as a power grid of a building or municipality. AC input 104 includes a first prong 106 connected with first line 108 which carries current from the power source to the x-ray scanning device and components thereof. AC input 104 includes a second prong 110 which is connected to a second line 112. AC input 104 includes a third prong 114 connected to ground 116. Third prong 114 provides a path for current to flow directly to ground 116 in case of a fault in the device or appliance, preventing potential electric shock or fire hazards. The third prong 114 is typically connected to the chassis or metal casing of the x-ray scanning device, ensuring that if a fault occurs and the casing becomes live, the current will flow to the ground instead of posing a danger to a user or operator of the x-ray scanning device. First line 108 connects downstream with AC filter 118 which clears AC input 104 from harmonics.

[0038] First line 108 feeds into first switch 120 and second switch 122 of circuit breaker 124. Circuit breaker 124 acts as the power ON/OFF switch for the x- ray scanning device. Also, circuit breaker 124 acts as a resettable fuse when an overload or short circuit occurs. Thus, circuit breaker 124 is a protective device that automatically interrupts the flow of current in the circuit when it exceeds a specified value, thereby preventing potential damage to equipment or harm to persons.

[0039] Worldwide, single-phase AC power grids generally include three types, namely, 120V/60Hz and 220-240V/60Hz split phase in North America and 220- 240V/50Hz in Europe, Africa, Asia and Australia. With power distribution box 102, a first input voltage range is 230VAC +/-10% and a second input voltage range is 115VAC +/-10%, both 50/60Hz +/-3Hz to operate with all above type grids. Accordingly, the second input voltage range is approximately half of the first input voltage range.

[0040] On initial activation of the power distribution box 102, activation of the power control board 126 is delayed. A microcontroller chip 128 on power control board 126 uses an initial algorithm to automatically measure the AC input 104 for several seconds to be able to average the AC input 104 readings and prevent erroneous grid type detection before energizing the components of the x-ray scanning device. [0041] After the voltage is analyzed, first primary winding 130 and second primary winding 132 of isolation transformer 134 are connected to AC input 104 either in series where 230V grid power, within the first input voltage range, is automatically detected and in parallel where 115V grid power, within the second input voltage range, is detected.

[0042] Connection of first primary winding 130 and second primary winding 132 to AC input 104 is via semiconductor device 136, which has a Negative Temperature Coefficient of conductivity (NTC). Accordingly, conductivity of semiconductor device 136 decreases as temperature increases and vice versa. Semiconductor device 136 prevents extremely high-current peaks due to the initial magnetic properties of the core 178 of isolation transformer 134. After several seconds, semiconductor device 136 is bypassed by relay 208 (FIG. 2), thereby excluding semiconductor device 136 from the circuit, because it is not needed to be active and will produce unwanted heat by reducing full conductivity during normal operation of the x-ray scanning device. The semiconductor device 136 helps to preserve relay contacts by limiting the current at switching moment and prevents unwanted initial tripping of circuit breaker 124 to off state because of current peak. Thereby, semiconductor device 136 serves as a current limiter between isolation transformer 134 and power control board 126.

[0043] Power control board 126 is controlled by a controller, such as microcontroller chip 128, which is shown in further detail in FIG. 4 and FIG. 6. Microcontroller chip 128 is operated via firmware 500 (FIG. 5). Power control board 126 contains at least one analog to digital converter (ADC) (not shown) and a timer (not shown) to accurately measure the moment when the sinusoidal signal of AC input 104 crosses the zero line as well as the AC signal amplitude. The phase timing is used, after an additional processing or calculation to switch relay contacts at the most appropriate moment when current is near zero, taking in consideration the inductive character of the winding load of isolation transformer 134. This improves the working condition of the relay contact as lower current is required. The AC input 104 voltage and x-ray scanning device current are dynamically measured by the analog to digital converter and then digitally processed to compensate for the non-linearity of the component. A moving average mathematical method is used to get noise-free value readings.

[0044] When AC input 104 is within the first input voltage range (230V), first primary winding 130 and second primary winding 132 are connected in series. Power received at input 138 from first line 108 provides AC power for the needs of the internal power control board 126. Power from second switch 122 of circuit breaker 124 is in electrical communication with end terminal 148 of second primary winding 132. Relay 202 (FIG. 2) contacts between input 150 and input 152 to connect the beginning terminal 154 of second primary winding 132 to the end terminal 156 of first primary winding 130. The beginning terminal 158 of first primary winding 130 is connected to first line 108 so the first primary winding 130 and the second primary winding 132 are connected in series to the grid with an appropriate begin-end sequence. In this configuration, first primary winding 130 and second primary winding 132 operate in series to provide magnetic flux to induce appropriate current at 230V to isolation transformer 134.

[0045] When AC input 104 is within the second input voltage range (115V), first primary winding 130 and second primary winding 132 are connected in parallel. Power received at input 138 from first line 108 is passed to power control board 126. Input 138 provides AC power for the needs of the internal power control board 126. Relay 204 (FIG. 2) contacts between input 138 and input 150 to feed power from line 160 into end terminal 156 of the first primary winding 130. The beginning terminal 158 of first primary winding 130 is fed from first line 108. Identically, through relay 206, contact between input 162 and input 152 allows the power from second line 112 to feed into beginning terminal 154 of the second primary winding 132. end terminal 148 of second primary winding 132 is fed from line 160. In this configuration, first primary winding 130 and second primary winding 132 operate in parallel to provide necessary magnetic flux to induce appropriate current from two windings at 115V to isolation transformer 134. [0046] Regardless of whether the first primary winding 130 and second primary winding 132 of isolation transformer 134 are connected in parallel or in series, first secondary winding 164 and second secondary winding 166 are connected in series. Thereby, first secondary winding 164 and second secondary winding 166 of isolation transformer 134 provide power to the components of the x-ray scanning device at the first input voltage range, preferably at 230V. Power control board 126 analyzes the supplied AC input 104 and uses appropriate internal configuration to output an internal (“System”) voltage of 230V to scanner components, like monitors, conveyor motor drive, etc., regardless of the region and country of installation. The DC-powered components are provided by regulated 12V DC output supply by using the AC/DC Power Supply Units (PSU), including first power supply unit 180 and second power supply unit 182, and a battery backup circuit of power control board 126. First power supply unit 180 and second power supply unit 182 together make up AC/DC converter 184.

[0047] Power control board 126 is equipped with five light-emitting diode (LED) lights (FIG. 7) to provide a visual indication of power supply status, such as to display the detected AC voltage and frequency (grid type) or an error, when the parameters of supplied power (voltage or frequency) are out of supported ranges and the x-ray scanning device is disconnected from AC input 104.

[0048] Power distribution box 102 further includes an electromagnetic compliance filter 168, or EMC filter, in electrical connection with the secondary side of isolation transformer 134 to further reduce from AC input 104 as well as to prevent harmonics from the internal components that may disturb the input grid.

[0049] Power control board 126 further includes at least one AC/DC converter 184 to ensure the powering of 12VDC components like the main computer, X- ray Image processing system, conveyor control circuit, and other components. Since a clean DC (i.e., ripple noise < 100mV) is preferred for specific components, but some other components like main computer (motherboard) have embedded DC/DC converters that can inject extra noise to DC lines, the DC powering is split to two separate groups either with their own power supply unit (PSU) or the “clean” DC lines of the same power supply unit are split through an EMC noise suppressing filter.

[0050] When AC input 104 is within the first input voltage range (230V) only one of linked switches, namely first switch 120, interrupts and protects against overload and both of the first primary winding 130 and the second primary winding 132 are connected in series, while the second switch 122 of circuit breaker 124 only interrupts powering of power control board 126.

[0051] When AC input 104 is within the second input voltage range (115V), the linked switches are used to interrupt simultaneously each of the first primary winding 130 and second primary winding 132 of isolation transformer 134 as well as the power control board 126. The linked contacts also protect against overloading as either of the switches turn off the other by way of the linkage feature of circuit breaker 124. Thereby, the same circuit breaker 124 may be used for first input voltage range and second input voltage range.

[0052] To energize the x-ray scanning device and components thereof, power leaves isolation transformer 134 via beginning terminal 154 of first secondary winding 164 and end terminal 170 of second secondary winding 166. Power is directed to outlets 172 to which components such as a x-ray emitter assembly (not shown), x-ray detector assembly (now shown) or USB devices (not shown), for example, may be connected to receive power.

[0053] End terminal 170 of second secondary winding 166 returns current to power control board 126 which in turn is relayed to second line 112 of AC input 104.

[0054] In one aspect, the DC supply circuit of the power control board 126 may be supported by an uninterruptible power supply 310 (UPS) which ensures that a computer connected with the power control board 126 continues to run in the event of AC power loss. A graceful and safe shutdown may be triggered in the event of grid power loss so that scan data or configuration settings are not lost. The uninterruptible power supply 310 may contain a rechargeable battery and its own circuit to maintain charging.

[0055] In addition to the aspects described above, power control board 126 includes a number of other features to ensure safety of other components of the system or of an operator using the system. For example, the power control board 126 includes a measurement circuit assembly 418 (FIG. 4) which continuously measures the input voltage, frequency and phase. The power control board 126 has an embedded communication periphery (UART) or communication circuit 414 (FIG. 4), which can be connected to a main motherboard of the x-ray scanning device to transfer AC power status data by using a safe isolated circuit as shown in FIG. 11. This data can be displayed to the operator via a monitor or can be used by algorithms within software or firmware 500 (FIG. 5) to alter or stop operation of the x-ray scanning device automatically and produce a warning, under certain circumstances.

[0056] Power distribution box 102 houses power control board 126 and other components of x-ray scanning device within a metal enclosure (not shown). The chassis, metal parts (by bond wires) and AC-powered components are connected to ground 116 by a low-resistance path. Power distribution box 102 and various other components of the x-ray scanning device may be connected to ground 116 by separate connections, separated for electrical safety and lower noise for DC-powered devices, for example.

[0057] Power distribution box 102 is also equipped with a circuit to immediately de-energize components by stopping the AC power from flowing to certain components once a dedicated safety button is pressed. Such components may include, for example, an x-ray source generator or conveyor motor.

[0058] In FIG. 2, there is shown a portion of the circuit diagram of FIG. 1 , illustrating in further detail relay 202, relay 206 and relay 204, which facilitate the electrical relationship between AC input 104 and isolation transformer 134. [0059] When AC input 104 is within the first input voltage range (230V), relay 202 connects the beginning terminal 154 of second primary winding 132 to the end terminal 156 of first primary winding 130. The beginning terminal 158 of first primary winding 130 is connected to first line 108 so the first primary winding 130 and the second primary winding 132 are connected in series to the grid with an appropriate begin-end sequence. In this configuration, first primary winding 130 and second primary winding 132 operate in series to provide magnetic flux to induce appropriate current at 230V to isolation transformer 134.

[0060] When AC input 104 is within the second input voltage range (115V), relay 204 contacts between input 138 and input 150 to feed power from line 160 into end terminal 156 of the first primary winding 130. The beginning terminal 158 of first primary winding 130 is fed from first line 108. Identically, through relay 206, contact between input 162 and input 152 allows the power from second line 112 to feed into beginning terminal 154 of the second primary winding 132. end terminal 148 of second primary winding 132 is fed from line 160. In this configuration, first primary winding 130 and second primary winding 132 operate in parallel to provide necessary magnetic flux to induce appropriate current from two windings at 115V to isolation transformer 134.

[0061] In FIG. 3, there is shown a block diagram of power distribution box 102 according to one aspect. Power is provided from source at AC input 104, which includes AC filter 118. Power is then routed to power control board 126 for automatic voltage detection. Once the voltage is automatically detected, power is routed to isolation transformer 134 in electrical communication with power control board 126 as previously described.

[0062] Power control board 126 is also electrically coupled with circuit breaker 124 which serves as the main ON/OFF switch for the x-ray scanning device and also acts as an interrupt against surges. Power control board 126 is also coupled with LED lights 302 which provide an indication of the status of the power control board 126. For example, LED lights 302 may include a first LED to indicate that the power control board 126 is operating in 230V series configuration, a second LED to indicate that the power control board 126 is operating in 115V parallel configuration, a third LED to indicate a 50Hz frequency, a fourth LED to indicate a 60Hz frequency and a fifth LED which indicates an error status.

[0063] Electromagnetic compliance filter 168 is electrically coupled with isolation transformer 134 at the secondary side thereof to filter power being provided to outlets 172 which are used for energizing components of the x-ray scanning device. Such components may include, for example, the x-ray generators (not shown), conveyor motor system (not shown), monitors (not shown), or other components (not shown). Electrically coupled between electromagnetic compliance filter 168 and outlets 172 for supplying power to components of the x-ray scanning device is relay 304 which serves as an emergency stop relay 304 for manually interrupting power output to the components of x-ray scanning device in the event of an emergency. Relay 304 may be connected with an emergency button circuit 314 accessible to a user or operator of the x-ray scanning device. Power control board 126 also electrically connects with the main computer (not shown) of the x-ray scanning device.

[0064] Electromagnetic compliance filter 168 also outputs to first power supply 306 and second power supply 308. First power supply 306 is a power supply for a connected uninterruptible power supply 310 with internal battery for supporting the DC supply circuit of the power control board 126. Uninterruptible power supply 310 allows for the main computer 312 of the x-ray scanning device, which is connected with the power control board 126, to continue to run in the event of AC power loss. A graceful and safe shutdown may be triggered if grid power is lost so that scan data or configuration settings are not lost. The battery of uninterruptible power supply 310 is preferably a rechargeable battery and has its own circuit to maintain charging. Second power supply 308 is preferably a low-ripple power supply. A DC supply with low ripple noise, typically less than 100mV, is preferred for some components. Second power supply 308 supplies power to those components. Components are appropriately connected to ground 116 [0065] Electromagnetic compliance filter 168 includes first capacitor 186, second capacitor 188 and metal oxide varistor 190 (MOV) component of electromagnetic compliance filter 168 are in electrical connection with the secondary isolated side of isolation transformer 134 for surge protection. This reduces disturbances from AC input 104 and prevents harmonics generated from internal components that may disturb the input grid. Metal oxide varistor 190 clamps if any high-voltage line-to-line surges pass through isolation transformer 134 to the secondary side thereof before reaching the AC inputs of internal system components, first capacitor 186 and second capacitor 188 reduce input harmonics by conducting them to ground 116 and, since the secondary side of isolation transformer 134 is “floating” they reduce return of unwanted harmonics from internal components, such as the integrated power AC/DC converters of the monitor and the motor drive, back to the AC grid as the value of parasitic capacitance between transformer windings is much lower than first capacitor 186 and second capacitor 188.

[0066] In FIG. 4, there is shown a block diagram of power control board 126 according to one aspect. Power control board 126 is controlled by a microcontroller chip 128 with firmware 500 (FIG. 5) embedded thereon, containing analog to digital converters (ADC), and a timer (not shown) to measure accurately the moment when AC input 104 sinusoidal signal crosses the zero line as well as the AC signal amplitude. The analog to digital converters may include AC/DC converter 184, for example and are embedded components of microcontroller chip 128, as shown in FIG. 6.

[0067] Power control board 126 further includes at least one, and preferably a plurality of, voltage-switching relays 402, internal power supply unit 404 (PSU), at least one protection fuse 406, transient voltage suppressor 408 (TVS), measurement circuit assembly 418, LED lights 302, communication circuit 414, and AC filter 118 for the secondary winding of the toroidal transformer. Measurement circuit assembly 418 includes voltage measurement circuit 410, current measurement circuit 412, frequency and phase measurement circuit 902 (FIG. 9) and input voltage amplitude circuit 904 (FIG. 9). One or both of voltage measurement circuit 410 and current measurement circuit 412 may be transformers.

[0068] Power control board 126 is preferably mounted to the internal metal sheet wall of the power distribution box 102 enclosure and is connected with the other components of power distribution box 102 assembly, preferably by 0.250 inch standard wide high-power quick-connect tabs. The components connected to the AC input 104 are insulated and rated for wide input voltage range 90-300VAC as well as to withstand to Hi-Pot testing.

[0069] In FIG. 5, there is shown firmware 500 according to one aspect. The microcontroller chip 128 is flashed with firmware 500 to perform measurements, analyses and switch ON/OFF the five relays of the semiconductor device responsible for NTC component clamping and series/parallel/off connection of the first primary winding 130 and second primary winding 132 of the toroidal isolation transformer 134 according to the AC input 104. Firmware 500 can be modified and updated, even on existing field scanners, to add more functionality to correct the algorithm and establish a link to the main computer of the x-ray scanning device.

[0070] When circuit breaker 124 is turned on at block 502, the microcontroller chip 128 is activated, and, at block 504, microcontroller chip 128 starts measuring the AC input 104 voltage amplitude and frequency for several seconds while all power relays are OFF to keep the x-ray scanning device deenergized.

[0071] At block 506, a check of the voltage average and/or frequency is made. If the voltage average as a calculated Root Mean Square value (V/n._rms) is in 115V +/- 10% range, then the first primary winding 130 and second primary winding 132 of isolation transformer 134 are connected in parallel. The first secondary winding 164 and second secondary winding 166 are always in series, so the ratio in this case is 1 :2, which provides 230V System voltage for the x-ray scanning device components. Similarly, if voltage value is in 230V +/- 10% range, the first primary winding 130 and second primary winding 132 are connected in series to get 1 :1 ratio and again 230V System voltage.

[0072] At block 508, the relays for parallel or series connection are set to the appropriate ON or OFF position depending on whether the power control board 126 will operate in parallel or series configuration.

[0073] As previously mentioned, the microcontroller chip 128 has an embedded communication periphery (UART) or communication circuit 414, which can be connected to a main motherboard of the x-ray scanning device to transfer AC power status data. As at block 512, the communication link is updated. As shown at block 514, the AC input 104 is passed through semiconductor device 136 with NTC conductivity until a predetermined time period of at least 1 second, in one aspect, after the switching is done to prevent a high current peak. If the predetermined time period has not elapsed, the NTC remains active and the NTC relay remains in the OFF position, as shown at block 516. If the predetermined time period has elapsed, the NTC is bypassed and the NTC relay is switched to the ON position, as shown at block 518. The exact moment of the relay contacts engaging is timed precisely with phase shift against a cross-zero reference point taking into consideration the typical mechanical delay of the relay, bouncing specifics and the transformer inductive load to be at near-zero current value when the contact is established.

[0074] If, during normal operation, the AC power becomes temporarily out of range, as at block 506, x-ray scanning device is disconnected from the AC power, as at block 520, and the operator is notified by LED lights, as at block 526, and operation of firmware 500 ends, as at block 516.

[0075] For safety reasons, it is preferred that the circuit breaker 124 is turned OFF and then ON again in order to restore operation of the x-ray scanning device and firmware 500.

[0076] As shown at block 510, the automatically detected voltage and frequency LED lights 302 may be activated so that the status of the x-ray scanning device is displayed at the power distribution box 102 front panel. Monitored values of voltage and frequency, as well as status information can also or instead be transferred by a UART-to-USB link to the main computer or motherboard of the x-ray scanning device.

[0077] FIG. 6 is a diagram illustrating programmable microcontroller chip 128 (MCU) of power control board 126, according to one aspect. Microcontroller chip 128 has various inputs and outputs to facilitate operation of power distribution box 102 and its subcomponents, as well as powering of components of the x-ray scanning device. Microcontroller chip 128 is also coupled to ground 116.

[0078] FIG. 7 is a diagram illustrating an LED array 702 having LED lights 302, according to one aspect. LED array 702 is in electrical communication with microcontroller chip 128 which outputs power and/or signals therefrom for selective activation and deactivation of LED lights 302. LED array 702 may be electrically coupled to ground 116.

[0079] FIG. 8 is a diagram illustrating in further detail, the implementation of control of relays 202, 204 and 206 of power control board 126 by microcontroller chip 128 shown in FIG. 2.

[0080] FIG. 9 is a diagram illustrating the internal configuration of power control board 126, including the AC/DC first power supply unit 180 and second power supply unit 182, frequency and phase measurement circuit 902 and input voltage amplitude circuit 904.

[0081] FIG. 10 is a diagram illustrating current measurement circuit 412 according to one aspect and electrical coupling between current measurement circuit 412 and microcontroller chip 128.

[0082] FIG. 11 is a diagram illustrating communication circuit 414 according to one aspect and electrical coupling between communication circuit 414 and microcontroller chip 128. [0083] While the invention has been described in terms of specific aspects, it is apparent that other forms could be adopted by one skilled in the art. For example, the methods described herein could be performed in a manner which differs from the aspects described herein. The steps of each method could be performed using similar steps or steps producing the same result but which are not necessarily equivalent to the steps described herein. Some steps may also be performed in different order to obtain the same result. Similarly, the apparatuses and systems described herein could differ in appearance and construction from the aspects described herein, the functions of each component of the apparatus could be performed by components of different construction but capable of a similar though not necessarily equivalent function, and appropriate materials could be substituted for those noted. Accordingly, it should be understood that the invention is not limited to the specific aspects described herein. It should also be understood that the phraseology and terminology employed above are for the purpose of disclosing the illustrated aspects, and do not necessarily serve as limitations to the scope of the invention.

Claims

CLAIMS What is claimed is:

1 . A circuit for power distribution in an x-ray scanning device, comprising: a transformer having at least two primary windings at a first side thereof and at least two secondary windings at a second side thereof, the at least two secondary windings connected in series for distributing power in a first voltage range to at least one x-ray scanning device component; and, a controller for receiving AC input in one of the first voltage range and a second voltage range that is approximately half of the first voltage range, the controller in electrical communication with the at least two primary windings and configured to connect the at least two primary windings with one another in series circuit when AC input is received in the first voltage range and to connect the at least two primary windings with one another in parallel circuit when AC input is received in the second voltage range for energizing the at least one x- ray scanning device component.

2. The circuit of claim 1 wherein: when the AC input is in the first voltage range, the controller closes a first relay between the end terminal of the first primary winding and the beginning terminal of the second primary winding, opens a second relay electrically coupled with the end terminal of the first primary winding between a live AC input and a neutral line and opens a third relay electrically coupled with the beginning terminal of the second primary winding between the live AC input and the neutral line; and, when the AC input is in the second voltage range, the controller opens the first relay, closes the second relay and closes the third relay.

3. The circuit of claim 1 further comprising: a circuit breaker in circuit with the at least two primary windings of the transformer to interrupt the at least two primary windings of the transformer after the circuit breaker detects one of an overload and a short circuit.

4. The circuit of claim 3, wherein the circuit breaker includes at least two circuit breaker relays each electrically coupled with a corresponding one of the at least two primary windings of the transformer, the at least two circuit breaker relays connected in series with one another to simultaneously interrupt the at least two primary windings after the circuit breaker detects the one of the overload and the short circuit.

5. The circuit of claim 1 , wherein the first voltage range is 230VAC +/-10% and the second voltage range is 115VAC +/-10%.

6. The circuit of claim 1 , further comprising at least one x-ray scanning device component in circuit with the second side of the transformer for receiving power therefrom.

7. The circuit of claim 6, further comprises: an electromagnetic compliance filter in circuit between the second side of the transformer and the at least one x-ray scanning device component.

8. The circuit of claim 7, wherein the electromagnetic compliance filter includes at least one of a capacitor for conducting input harmonics to ground to reduce input harmonics reaching the at least one x-ray scanning device component and, a surge protector to prevent surges that succeed in passing through the transformer to the secondary side from reaching the at least one x-ray scanning device component.

9. The circuit of claim 1 , wherein the controller is part of a power control board for controlling distribution of AC input power supply to components of the x-ray scanning device.

10. The circuit of claim 9, wherein the power control board is electrically coupled with an uninterruptible power source.

11. The circuit of claim 10, wherein the uninterruptible power source includes a first power supply unit for x-ray scanning device components which have embedded AC/DC converters and a second power supply unit for x-ray scanning device components which are absent an embedded AC/DC converter.

12. The circuit of claim 1 , further comprising: an AC filter for measuring AC input voltage range, wherein the controller receives the measured AC input in the first voltage range and the second voltage range.

13. A method for power distribution in an x-ray scanning device comprising the steps of: energizing, via AC input, a circuit having a controller; receiving, at the controller, AC input in one of a first voltage range and a second voltage range that is approximately half of the first voltage range, the controller in electrical communication with a transformer having at least two primary windings at a first side thereof and at least two secondary windings at a second side thereof, the at least two secondary windings connected in series for distributing power in the first voltage range to at least one component of the x-ray scanning device; connecting the at least two primary windings with one another in series circuit when AC input is received in the first voltage range and connecting the at least two primary windings with one another in parallel circuit when AC input is received in the second voltage range; and, distributing power from the second side of the transformer in the first voltage range to energize at least one x-ray scanning device component.

14. The method of claim 13 further comprising the steps of: when the AC input is in the first voltage range, via the controller, closing a first relay between the end terminal of the first primary winding and the beginning terminal of the second primary winding, opening a second relay electrically coupled with the end terminal of the first primary winding between a live AC input and a neutral line and opening a third relay electrically coupled with the beginning terminal of the second primary winding between the live AC input and the neutral line; and, when the AC input is in the second voltage range, via the controller, opening the first relay, closing the second relay and closing the third relay.

15. The method of claim 13, wherein prior to the receiving step, the controller automatically measures the voltage, frequency and amplitude of the AC input.

16. The method of claim 13, further comprising: interrupting, via a circuit breaker in circuit with the at least two primary windings of the transformer, the at least two primary windings of the transformer after the circuit breaker detects one of an overload and a short circuit.

17. The method of claim 13, wherein the first voltage range is 230VAC +/-10% and the second voltage range is 115VAC +/-10%.

18. The method of claim 13, further comprising: at least one of conducting input harmonics to ground and preventing surges via an electromagnetic compliance filter in circuit between the second side of the transformer and the at least one x-ray scanning device component.

19. An x-ray scanning device comprising: a transformer having at least two primary windings at a first side thereof and at least two secondary windings at a second side thereof, the at least two secondary windings connected in series for distributing power in a first voltage range to at least one x-ray scanning device component; and, a controller for receiving AC input in one of the first voltage range and a second voltage range that is approximately half of the first voltage range, the controller in electrical communication with the at least two primary windings and configured to connect the at least two primary windings with one another in series circuit when AC input is received in the first voltage range and to connect the at least two primary windings with one another in parallel circuit when AC input is received in the second voltage range for energizing the at least one x- ray scanning device component.

20. The x-ray scanning device of claim 19 wherein the transformer and the controller are components of a power distribution system of the x-ray scanning device.