Monorail bidirectional pulse driver

Abstract

Various arrangements relating to a bi-directional pulse driver circuit are presented herein. The driver circuit may include a forward pulse trigger circuit and a forward pulse loop circuit. The forward pulse loop circuit may include a first silicon controlled rectifier (SCR) activated by a forward pulse trigger circuit. The driver circuit may include a reverse pulse trigger circuit and a reverse pulse loop circuit. The reverse pulse loop circuit may include a second SCR activated by a reverse pulse trigger circuit. The driver circuit may also include a controller that activates the forward pulse trigger circuit and the reverse pulse trigger circuit in a first mode to cause a current pulse to be applied to the load in a forward direction, and activates the forward pulse trigger circuit and the reverse pulse trigger circuit in a second mode to cause a current pulse to be applied to the load in an opposite direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 407,551, filed on September 16, 2022, entitled “Single Rail Bidirectional Pulse Driver,” and U.S. Non-Provisional Application No. 18 / 234,998, filed on August 17, 2023, entitled “Single Rail Bidirectional Pulse Driver,” the entire disclosures of which are incorporated herein by reference for all purposes. Background Art

[0002] When current needs to be driven through a load alternately in two directions, a conventional H-bridge circuit may be used. In an H-bridge circuit, four transistors, such as metal oxide semiconductor field effect transistors (MOSFETs), are used to control which side of the load the power source is connected to and which side the ground is connected to. However, in some cases, an H-bridge circuit is not desirable. For example, having multiple transistors may require a large amount of space within the device (e.g., on a printed circuit board), and may be relatively expensive due to the number of transistors, especially if power transistors, such as power MOSFETs, are used. Summary of the invention

[0003] Various embodiments related to bidirectional pulse driver circuits are described. In some embodiments, a bidirectional pulse driver circuit is described. The device may include a forward pulse trigger circuit. The device may include a forward pulse loop circuit connected to a load. The forward pulse loop circuit may include a first silicon controlled rectifier (SCR) that can be activated by the forward pulse trigger circuit. The device may include a reverse pulse trigger circuit. The device may include a reverse pulse loop circuit connected to the load. The reverse pulse loop circuit may include a second SCR that can be activated by the reverse pulse trigger circuit. The device may include a controller that communicates with the forward pulse trigger circuit and the reverse pulse trigger circuit. The controller may activate the forward pulse trigger circuit and the reverse pulse trigger circuit in a first mode so that a current pulse is applied to the load in a first direction. The controller may activate the forward pulse trigger circuit and the reverse pulse trigger circuit in a second mode so that a current pulse is applied to the load in a second direction.

[0004] Embodiments of such an apparatus may include one or more of the following features: The forward pulse loop circuit may include a first capacitor. The first terminal of the first capacitor may be connected to the anode of the first SCR. The second terminal of the first capacitor may be connected to a terminal of the load. The reverse pulse loop circuit may include a second capacitor. The first terminal of the second capacitor may be connected to the cathode of the second SCR. The second terminal of the first capacitor may be connected to a terminal of the load and a second terminal of the first capacitor. The first mode may include activating the reverse pulse trigger circuit multiple times and then activating the forward pulse trigger circuit. The second mode may include activating the forward pulse trigger circuit multiple times and then activating the reverse pulse trigger circuit. The apparatus may further include a load. The load may include a wire coiled around one or more soft magnets. The polarity of the one or more soft magnets may be flipped based on the direction of the current pulse. The apparatus may further include a tablet system including a tablet computer and a base. The one or more soft magnets, the forward pulse trigger circuit, the forward pulse loop circuit, the reverse pulse trigger circuit, and the reverse pulse loop circuit may be included as part of the base. The tablet computer may be configured to output an indication that the tablet computer and the base are ready to be separated based on whether the controller activates the first mode or the second mode.

[0005] In some embodiments, a method for reversing the polarity of a soft magnetic body using a bidirectional pulse driver circuit is described. The method may include determining a desired polarity of the soft magnetic body. The method may include adjusting the potential of a load bias point by triggering a first silicon controlled rectifier (SCR) based on the desired polarity. The method may include allowing the first SCR to achieve a low current dropout after triggering the first SCR. The method may include triggering a second SCR based on the desired polarity to apply a current pulse to the load. The current pulse may change the polarity of the soft magnetic body to the desired polarity.

[0006] Embodiments of this method may include one or more of the following features: determining a second desired polarity of the soft magnet. The method may further include adjusting the potential of the load bias point by triggering the second SCR based on the second desired polarity. The method may further include allowing the second SCR to achieve a low current shutoff after triggering the second SCR. The method may further include triggering the first SCR to apply a second current pulse to the load in a direction opposite to the current pulse based on the second desired polarity. The second current pulse may change the polarity of the soft magnet to a second desired polarity. The load may include a wire coiled around the soft magnet. Triggering the first SCR and the second SCR may be performed according to a first defined mode or a second defined mode based on the desired polarity. The controller may trigger the first SCR via a first trigger circuit and trigger the second SCR via a second trigger circuit. The current pulse may be generated using a charge stored in one or more capacitors. The first SCR and the second SCR may be part of a circuit integrated in a flat panel docking system. The method may further include outputting a message indicating the state of the flat panel docking for presentation by a display of a computerized flat panel of the flat panel docking system after triggering the second SCR.

[0007] In some embodiments, a tablet docking system is described. The system may include a computerized tablet. The system may include a docking station to which the computerized tablet is docked. The system may include a bidirectional pulse driver circuit, the bidirectional pulse driver circuit including a forward pulse trigger circuit. The bidirectional pulse driver circuit may include a forward pulse loop circuit connected to a load, the load including a wire coiled around a soft magnetic body. The forward pulse loop circuit may include a first silicon controlled rectifier (SCR) that can be activated by the forward pulse trigger circuit. The bidirectional pulse driver circuit may include a reverse pulse trigger circuit. The bidirectional pulse driver circuit may include a reverse pulse loop circuit connected to the load. The reverse pulse loop circuit may include a second SCR that can be activated by the reverse pulse trigger circuit. The bidirectional pulse driver circuit may include a controller that communicates with the forward pulse trigger circuit and the reverse pulse trigger circuit. The controller may activate the forward pulse trigger circuit and the reverse pulse trigger circuit in a first mode so that a current pulse is applied to the load in a first direction to set the polarity of the soft magnetic body. The controller may activate the forward pulse trigger circuit and the reverse pulse trigger circuit in a second mode so that a current pulse is applied to the load in a second direction to set the polarity of the soft magnetic body opposite to the first mode.

[0008] Embodiments of such a system may include one or more of the following features: The polarity of the soft magnet associated with the first mode may allow the computerized tablet to be more easily removed from the docking station than the polarity of the soft magnet associated with the second mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The nature and advantages of the various embodiments may be further understood with reference to the following drawings.In the accompanying drawings, similar components or features may have the same reference numeral.

[0010] Figure 1 A block diagram of an embodiment of a bidirectional pulse driver circuit is shown.

[0011] Figure 2 A circuit diagram of an embodiment of a bidirectional pulse driver circuit is shown.

[0012] Figure 3A An embodiment of a system using a bidirectional pulse driver circuit to assist in docking and undocking a tablet from a base is shown.

[0013] Figure 3B An embodiment of an electronic device docking with a docking station using magnets is shown.

[0014] Figure 3C A front view of a docking station that can be docked and undocked using magnets is shown.

[0015] Figure 3D A rear view of an embodiment of a system showing an electronic device docked with a docking station via magnets.

[0016] Figure 4 An embodiment of a method for using a bidirectional pulse driver circuit is shown.

[0017] Figure 5 An embodiment of a method for reversing the polarity of a soft magnetic body using a bidirectional pulse driver circuit is shown.

[0018] Figure 6 A graph showing a positive current pulse applied to a load by a bidirectional pulse driver circuit.

[0019] Figure 7 A graph showing a negative current pulse applied to a load by a bidirectional pulse driver circuit.

[0020] Figure 8 A graph showing a series of firing pulses applied to a pair of silicon controlled rectifiers (SCRs) of a bidirectional pulse driver circuit. DETAILED DESCRIPTION

[0021] The polarity of the soft magnet can be reversed based on the direction in which the current pulse is applied to the wire coiled around the soft magnet. The soft magnet can be used for various purposes, such as for holding an electronic device in place when it is docked. As an example, when a tablet computer is docked with a base, the soft magnet can have a first polarization, which helps the tablet computer remain firmly docked with the base. When the tablet computer is to be removed from the docking station, the polarity of the soft magnet can be reversed, resulting in the docking station and the tablet computer being separated, or at least making it relatively easier for the user to physically separate the tablet computer from the docking station.

[0022] Detailed herein is an arrangement for a circuit that allows current pulses to be applied in two directions to a load, such as one or more soft magnetic bodies wound with a wire. The circuit may utilize multiple SCRs to control when current is allowed to flow to the load. The circuit detailed herein may allow high current and high voltage pulses to be applied to a load, such as an electropermanent magnet assembly including one or more soft magnetic bodies wound with a wire. Further, the embodiments detailed herein may rely on a single power rail.

[0023] Further details are provided with respect to the accompanying drawings. Figure 1 A block diagram of an embodiment of a bidirectional pulse driver circuit 100 (e.g., "circuit 100") is shown. Circuit 100 may include: a voltage source 105; a load 110; a forward pulse trigger circuit 121; a forward pulse loop circuit 122; a reverse pulse trigger circuit 131; a reverse pulse loop circuit 132; and a controller 140. Voltage source 105 generates a single positive voltage (a single "rail") and is connected to forward pulse loop circuit 122 and reverse pulse loop circuit 132; however, it should be understood that voltage source 105 may additionally provide power to other components of circuit 100.

[0024] The load 110 may be one or more devices or circuits to which current pulses (or in other words, voltage pulses) are driven in the forward and reverse directions. That is, in some cases, pulses may be applied to terminals 111 of the load 110, while in other cases, similar pulses may be applied to terminals 112 of the load. The load may be an inductive load, meaning that the load has significant inductance. For example, the load 110 may be modeled as an inductor and a resistor, such as Figure 2. In some embodiments, the load 110 may have an inductance between 1.5 uH and 5.5 uH and a resistance between 100 milliohms and 500 milliohms. In some embodiments, the load 110 may include an electropermanent magnet assembly, which includes one or more soft magnets. The load 110 may represent one or more wires or one or more coils wound around one or more soft magnets, which may be present in one or more hard magnets of the electropermanent magnet assembly. By passing a current pulse through a wire wound or coiled around a soft magnet in a specific direction, the polarity of such a soft magnet can be relatively easily flipped (compared to a hard magnet). Once a pulse has been applied to a wire coiled around a soft magnet in a first specific direction, the polarity of the soft magnet can be set. The polarity can remain in the same state until a current pulse passes through a wire or coil wound around a soft magnet in a second opposite direction, which causes the polarity to flip. Once flipped, the polarity can remain in this state again until a current pulse is applied again in the first direction. In other embodiments, the load may be some other form of inductive load or non-inductive load. As an example, some form of motor may be used as the load 110 .

[0025] The forward pulse trigger circuit 121 can be used to trigger the activation of the forward pulse loop circuit 122 in response to a signal or command from the controller 140. The forward pulse trigger circuit 121 may include multiple components, including physical switches, transistors, MOSFETs, resistors, and diodes to generate a (voltage or current) pulse to trigger the forward pulse loop circuit 122. In some embodiments, the controller 140 may be able to directly trigger the forward pulse loop circuit 122; however, in other embodiments, the voltage or current output by the controller 140 may be insufficient, and therefore an intermediary forward pulse trigger circuit 121 may be used to trigger the forward pulse loop circuit 122. It is worth noting that the forward pulse trigger circuit may only trigger the activation of the forward pulse loop circuit 122; when a condition is met, such as the amount of current passing through the loop drops below a defined threshold, the forward pulse loop circuit 122 may deactivate itself.

[0026] The forward pulse loop circuit 122 serves two purposes: first, to generate a current pulse through the load 110, which causes the current pulse to pass through the load 110 from terminal 112 to terminal 111; and second, to allow the reverse pulse loop to generate a current pulse through the load 110, which causes the current pulse to pass through the load 110 from terminal 111 to terminal 112 (i.e., in the opposite direction).

[0027] The forward pulse loop circuit 122 is triggered by the forward pulse trigger circuit 121 and can be triggered in two situations. First, when a current pulse is to be applied from terminal 111 to terminal 112 through load 110, the forward pulse loop circuit 122 can be triggered once or multiple times to eliminate or at least reduce the charge that has been stored in the forward pulse loop circuit 122. (It is worth noting that when the load 110 includes a wire or coil wrapped around one or more soft magnets, occasional pulses that do not change the polarity of the soft magnets generally do not have an adverse effect on the magnets or the circuit). Secondly, when a current pulse is to be applied from terminal 112 to terminal 111 through load 110, the forward pulse loop circuit 122 can be triggered so that the current pulse passes from terminal 112 to terminal 111 through load 110.

[0028] The reverse pulse trigger circuit 131 may operate similarly to the forward pulse trigger circuit 121 as previously detailed, but instead functions as a trigger to activate the reverse pulse loop circuit 132. The reverse pulse loop circuit 132 serves two purposes: first, to generate a current pulse through the load 110, which results in a current pulse through the load 110 from the terminal 111 to the terminal 112; and second, to allow the forward pulse loop circuit 122 to generate a current pulse through the load 110, which results in a current pulse through the load 110 from the terminal 112 to the terminal 111.

[0029] The reverse pulse loop circuit 132 is triggered by the reverse pulse trigger circuit 131 and can be triggered in two situations. First, when a current pulse is to be applied from terminal 112 to terminal 111 through load 110, the reverse pulse loop circuit 132 can be triggered once or more times to eliminate or at least reduce the charge that has been stored in the reverse pulse loop circuit 132. (As previously mentioned, when the load 110 is a wire wound around one or more soft magnets, occasional pulses that do not change the polarity of the soft magnets generally do not have an adverse effect on the magnets or the circuit.) Second, when a current pulse is to be applied from terminal 111 to terminal 112 through load 110, the reverse pulse loop circuit 132 can be triggered so that the current pulse passes from terminal 111 to terminal 112 through load 110.

[0030] Therefore, as described above, both the forward pulse loop circuit 122 and the reverse pulse loop circuit 132 are activated in different modes according to the direction in which the current pulse should be applied to the load 110. The controller 140 can be used to control the forward pulse loop circuit 121 and the reverse pulse loop circuit 131 in a certain mode according to the direction in which the current pulse is to be applied to the load 110. The controller 140 can be a processor, a microcontroller, an ASIC, or some other processing device or processing system capable of receiving a command and outputting a control mode of a signal based on the command. The external command can be received from another device, another processing device existing in the same device where the circuit 100 is located, or another process executed on the same processor used as the controller 140. When the command is received, the controller 140 can determine the direction in which the current pulse is to be applied to the load 110, and can activate both the forward pulse trigger circuit 121 and the reverse pulse trigger circuit 131 in an appropriate mode so that the desired current pulse is applied to the load 110.

[0031] Figure 2 A circuit diagram of an embodiment of a bidirectional pulse driver circuit ("circuit 200") is shown. Circuit 200 may include: a load 210; a forward pulse trigger circuit 121; a forward pulse loop circuit 222; a reverse pulse trigger circuit 131; a reverse pulse loop circuit 232; and a controller 140. Controller 140, forward pulse trigger circuit 121, and reverse pulse trigger circuit 131 may be configured in accordance with the embodiment of the present invention. Figure 1 The circuit 100 operates as detailed above.

[0032] Load 210, which represents a possible embodiment of load 110, is represented as an inductor and resistor connected in series. Inductor and resistor are intended to represent that the load has inductance and resistance, such as that provided by an electro-permanent magnet assembly including one or more soft magnets, each of which is surrounded by a coil of wire through which current pulses are passed.

[0033] The positive pulse loop circuit 222 can represent Figure 1 100 of the circuit 100. The forward pulse loop circuit 222 may include: a capacitor 223; a resistor 224; a resistor 225; and an SCR 226. The reverse pulse loop circuit 232 may represent Figure 1An embodiment of a reverse pulse loop circuit 132 of circuit 100. Reverse pulse loop circuit 232 may include: capacitor 233; resistor 234; resistor 235; and SCR 236. SCR 226 and SCR 236 may be used as Schottky diodes with gates. In an SCR, when the gate is triggered, current is allowed to flow from the anode of the SCR to the cathode. The current is allowed to continue to flow in this direction until the amount of current drops below a threshold (defined by the characteristics of the SCR), the SCR enters a cutoff mode and electrically disconnects the anode of the SCR from the cathode. In other embodiments, similar components or combinations of components may be used instead of SCRs to achieve similar functions. As an example, a gallium nitride (GaN) FET may be used.

[0034] In a steady state, when both SCR 226 and SCR 236 are not disconnected due to being triggered by the forward pulse trigger circuit 121 or the reverse pulse trigger circuit 131, respectively, the voltage source 205 is used to charge capacitors 223 and 233. In some embodiments, capacitors 223 and 233 may have the same capacitance, which may be between 50 μF and 300 μF. Over time, charge will accumulate on capacitors 223 and 233, so that approximately half of the potential of the voltage source 205 exists on capacitor 223 and the other half exists on capacitor 233. Resistor 224 (which may have a resistance between 100 ohms and 10,000 ohms) prevents a large amount of current from being drawn from the voltage source 205 when charging capacitors 223 and 233, and prevents capacitors 223 and 233 from recharging too quickly during activation of the forward pulse loop circuit 222 or the reverse pulse loop circuit 232. In some embodiments, resistor 224 is optional if voltage source 205 can provide current limiting and / or capacitor charge state detection. For example, a high voltage capacitor charger controller can be used as voltage source 205 with resistor 224 eliminated from the circuit.

[0035] If a current pulse is to be applied to the load 210 at the terminal 212, the potential at the node 250 (which may be referred to as the load bias) may first be reduced to as close to ground as possible. To this end, the controller 140 may cause the reverse pulse trigger circuit 131 to trigger the SCR 236 one or more times (e.g., a pulse train may be applied to the gate of the SCR 236), which causes the charge stored in the capacitor 233 to discharge through the load 210 in the direction indicated by the arrow 238. Although the potential present at the node 250 may not completely reach ground, 90 to 99% of the charge stored by the capacitor 233 may be discharged, thereby allowing the node 250 to temporarily act as a virtual ground. When the SCR 236 enters the cutoff mode, the capacitor 233 may immediately begin to recharge; therefore, the shorter the time after the SCR 236 enters the cutoff mode that triggers the forward pulse trigger circuit 121, the higher the size of the forward current pulse.

[0036] After the SCR 236 of the reverse pulse trigger circuit 232 has entered the cutoff mode, the controller 140 can trigger the forward pulse trigger circuit 121 to output a single trigger to the SCR 226. The single trigger activates the gate of the SCR 226, so that a single current pulse is applied to the terminal 212 of the load 210, as indicated by arrow 228. If the load 210 includes a wire wound around one or more soft magnets (such as an electropermanent magnet assembly including one or more soft magnets), the current pulse through the forward pulse loop circuit 222 can reverse the polarity of the soft magnet if the polarity of the soft magnet is opposite to the direction associated with arrow 228.

[0037] However, if a current pulse is to be applied to load 210 at terminal 211 instead, the potential at node 250 may first increase to as close to the rail voltage of voltage source 205 as possible. To this end, controller 140 may cause forward pulse trigger circuit 121 to trigger SCR 226 one or more times (e.g., a pulse train may be applied to the gate of SCR 226), which causes the charge stored in capacitor 223 to discharge through load 210 in the direction indicated by arrow 228 and charge capacitor 233 up to the rail voltage. Although the potential present at node 250 may not fully reach the rail voltage, 90 to 99% of the charge stored by capacitor 223 may be discharged, allowing node 250 to act as a virtual rail. When SCR 226 enters the cutoff mode, capacitor 223 may immediately begin to recharge; therefore, the smaller the time after SCR 226 enters the cutoff mode that triggers reverse pulse trigger circuit 131, the higher the size of the reverse current pulse.

[0038] After the SCR 226 of the forward pulse trigger circuit 222 has entered the cutoff mode, the controller 140 can trigger the reverse pulse trigger circuit 131 to output a single trigger to the SCR 236. The single trigger activates the gate of the SCR 236 so that a single current pulse is applied to the terminal 211 of the load 210, as indicated by arrow 238. If the load 210 includes a wire coiled around one or more soft magnetic bodies, the current pulse through the reverse pulse loop circuit 232 can reverse the polarity of the soft magnetic body if the polarity of the soft magnetic body is opposite to the direction associated with arrow 238.

[0039] Resistors 225, 234, and 235 may represent parasitic resistances of the circuit and may not represent discrete components. These resistors may be in the range of 1 milliohm to 900 milliohm.

[0040] According to circuit theory, the components of circuit 200 may have alternative implementations. As an example, capacitor 223 may be implemented as a plurality of parallel capacitors. It is worth noting that, except for SCR 226 and 236, there are no other components in forward pulse loop circuit 222 and reverse pulse loop circuit 232.

[0041] It is worth noting that in circuit 200, some resistors may not be discrete components of the circuit, but are included in the circuit to represent the secondary effects of the components. For example, resistors 225, 234, and 235 may not be discrete components, but may represent the resistance of non-ideal components of the circuit.

[0042] Figure 3A An embodiment of a tablet docking system 300A ("system 300A") is shown that uses a bidirectional pulse driver circuit to assist in docking and detaching a tablet with a docking station (which may alternatively be referred to as a base). The docking station 310 may include components such as: a power source; a bracket that can support a tablet 320; a spring-loaded pin 311; an electromagnet assembly including a soft magnet 312; a speaker; a microphone; and one or more status lights. The tablet 320 may include: a battery; a display (e.g., a touch screen); a speaker; a microphone; a camera; contacts 321; and a permanent magnet 322. These magnets may help align the tablet 320 with the docking station 310 when the user places the tablet 320 on the docking station 310, or may be used to securely attach the docking station 310 to the tablet 320. When engaged with the correct polarity, such soft magnets may make it relatively difficult or relatively easy for a user to disengage the tablet 320 from the docking station 310.

[0043] The soft magnet 312 can be used to removably attach to the permanent magnet 322, which can be located at the back of the flat plate 320. The specific number and location of the soft magnet 312 and the permanent magnet 322 can vary from embodiment to embodiment. Further, in some embodiments, the soft magnet 312 is located on the flat plate 320 instead of the docking station 310 (and the permanent magnet 322 can be located on the docking station 310).

[0044] In system 300A, docking station 310 can generally be left in a particular position and connected to line power, such as via an electrical outlet. When placed on docking station 310, it may be desirable to securely engage tablet 320 with docking station 310 so that tablet 320 is aligned and held in a particular position (e.g., so that the electrical contacts of docking station 310 and tablet 320 are aligned and in contact). Circuit 100 or circuit 200 can be present in docking station 310, tablet 320, or both to change the polarity of one or more soft magnets of the electropermanent magnet assembly to help keep tablet 320 and docking station 310 securely mated, or to disengage tablet 320 from docking station 310 relatively easily.

[0045] If circuit 100 or circuit 200 is present in docking station 310, control signals may be sent from tablet 320 to control circuit 100 or circuit 200. If present in docking station 310, wireless messages (e.g., mesh network protocols, Thread®, Bluetooth®, Wi-Fi®, etc.) may be sent from docking station 310 to tablet 320 if a message is to be output to a user, such as described in detail with respect to method 500.

[0046] Use as about Figures 1 to 2 Other possible embodiments of the system of the single-rail bidirectional pulse driver circuit detailed in the can include any two devices that can be removably mated, such as: a smart phone and a charger or base; a laptop and a docking station; a thermostat and a back plate; a smart watch and a charger; a smart doorbell and a mounting bracket; earbuds and a charger; headphones and a charger; a gaming device and a docking station or a charger. Further, embodiments of circuits 100 and 200 can be used in various other situations where it is necessary to drive a load with a current pulse from the AC terminals of the load.

[0047] FIG. 3B to FIG. 3D Indicates that it can contain Figure 1 and Figure 2 An embodiment of a system. Figure 3BAn embodiment of an electronic device 300B is shown, which is configured to dock with a docking station using magnets and has electrical contacts 330. The electronic device 300B can be a tablet computer, or more specifically, a tablet computer used as a home assistant device or hub as previously described in detail. One or more magnets can be hidden in the electronic device 300B, behind the back 335. The electronic device 300B includes a plurality of conductive contacts 330 (e.g., metal pads) that are used to transmit data with the docking station and / or obtain power from the docking station when the electronic device 300B is in a docking position. As shown, there are four electrical contacts 330. In other embodiments, there may be a greater or lesser number of electrical contacts 330. The arrangement of the electrical contacts 330 may also vary depending on the embodiment. In some embodiments, the electrical contacts include, for example, one or more contact pads, one or more contact pins, or a combination of pads and contact pins. Other components (such as a camera 325) may be present on the back 335 or accessible through the back.

[0048] Figure 3C A front view of a docking station 300C according to some embodiments is shown. The docking station 300C may include a mating system. The mating system of the docking station 300C may include a magnet system. The magnet system may include one or more magnets that are arranged to align and magnetically couple with corresponding one or more magnets of a magnet system of an electronic device (such as electronic device 300B) docked with the docking station 300C, so that the mating surface (e.g., back surface 335) of the electronic device is held against the mating surface 340 of the docking station 300C by the magnetic system of the docking station 300C and the magnetic field of the magnetic system of the electronic device.

[0049] The magnetic field sensor of docking station 300C may include, for example, one or more magnetic field sensors, one or more magnetometers, one or more Hall effect sensors, and / or one or more other types of sensors configured to sense the presence of a magnet or magnetic field. The magnetic field sensor may be configured to generate a signal indicating the magnitude of the magnetic field, which may indicate proximity to one or more magnets.

[0050] The docking station 300C may include a processing system configured to receive a signal indicating whether the electronic device is properly docked with the docking station 300C. The signal may be initiated, for example, by either or both of a magnetic field sensor of the docking station 300C and a magnetic field sensor of the electronic device. In response to receiving the signal, the processing system may be configured to provide power and / or communication signals to the electronic device through the electrical contacts 345 of the docking station 300.

[0051] In some embodiments, the docking station 300C may include an internal speaker that is directed toward the speaker face 342. The docking station 300C may be configured to cause the internal speaker to generate sound based on data from, for example, an audio file, or based on a signal from, for example, a microphone system.

[0052] In some embodiments, the docking station 300C may include stabilizing feet 344 that significantly reduce sliding movement on the surface on which the docking station 300C is placed. For example, the docking station 300C may experience vibrations, such as due to the use of a speaker of the docking station 300C. The stabilizing feet 344 of the docking station 300C can be shaped to generate sufficient friction with the surface to minimize or prevent sliding movement.

[0053] Legs 344 can include an elastomeric material. For example, in some embodiments, legs 344 include silicon. Additionally, legs 344 can be attached to the surface of the housing of docking station 300C using an adhesive. In some embodiments, legs 344 are attached to the surface of the housing by topological features of legs 344 that protrude through a hole in the surface of the housing. In some embodiments, legs 344 are attached to the surface of the housing using another mechanism, such as a fastener.

[0054] Figure 3D A rear view of an embodiment of a system 300D of an electronic device 300B docked with a docking station 300C is shown according to some implementations of the present disclosure. In some embodiments, either or both of the electronic device 300B and the docking station 300C include a magnet or magnet system, e.g., similar or identical to those discussed elsewhere herein, that holds the electronic device 300B in place against the docking station 300C, e.g., such that a mating face 335 of the electronic device 300B is held in place against a mating face 340 of the docking station 300C.

[0055] You can use about Figure 1 3 to perform various methods. Figure 4 An embodiment of a method 400 for using a bidirectional pulse driver circuit is shown. The method 400 may be used Figure 1 , Figure 2 The method 400 may be performed by a circuit of or some variation of the circuit. The method 400 may be performed by a system including such a circuit, which is integrated as part of a larger system, such as the tablet docking system detailed in FIG. 3 .

[0056] At block 410, a determination is made, such as by a controller device (eg, a processor), as to the type of pulse that needs to be applied to the load. The pulse type may be selected from a forward pulse or a reverse pulse.

[0057] At block 420, the load bias of the circuit may be adjusted based on the determined pulse type. The load bias may be used to bring the potential at the terminals of the load as close to the rail voltage (e.g., 90% to 99% of the rail voltage) or as close to the ground potential (e.g., 90% to 99% of the ground potential). The load bias may be adjusted by triggering the first SCR of one of the two pulse loop circuits. If a forward pulse is to be applied to the load, the first SCR is the SCR of the reverse pulse loop circuit; and if a reverse pulse is to be applied to the load, the first SCR is the SCR of the forward pulse loop circuit. The triggering of block 420 may involve applying a series of one or more pulses to trigger the first SCR one or more times. For example, in some embodiments, block 420 includes applying a pattern having 2 to 5 pulses to the first SCR to trigger it multiple times. When executing block 420, the second SCR remains disconnected so that virtually no current passes through it.

[0058] At block 430, once the amount of current through the first SCR drops below a defined threshold, the first SCR enters a cutoff mode, causing the SCR to change from closed to open. As detailed with respect to block 420, the first SCR may be triggered multiple times; therefore, blocks 420 and 430 may be performed multiple times before proceeding to block 440.

[0059] At box 440, the controller triggers the second SCR to generate the current pulse determined at box 410. Box 440 can be performed immediately after box 430 (e.g., within 0.1 ms) to prevent the load bias point potential from returning substantially to the midpoint between the rail voltage and the ground potential. If a forward current pulse is to be generated, the second SCR is an SCR of a forward pulse loop circuit; if a reverse current pulse is to be generated, the second SCR is an SCR of a reverse pulse loop circuit. If the load bias is set to approximately the rail voltage, triggering the SCR of the reverse pulse loop circuit causes a reverse current pulse to flow through the load from the load bias point. If the load bias is set to approximately the ground voltage potential, triggering the SCR of the forward pulse loop circuit causes a forward current pulse to flow through the load to the load bias point.

[0060] Boxes 420 and 440 can be understood as time-varying pulse patterns applied by the controller to the first SCR and the second SCR. Thus, depending on the determined pulse type, the controller can output one of the two pulse patterns to the SCR or to the intermediary trigger circuit, which in turn triggers the gates of the SCRs.

[0061] At block 450, once the amount of current through the second SCR drops below a defined threshold, the second SCR enters a cutoff mode, causing the second SCR to change from closed to open. At this point, the method 400 is complete and may be repeated at some future point in time to apply another current pulse, possibly in the opposite direction, to the load.

[0062] Figure 5 An embodiment of a method 500 for reversing the polarity of one or more soft magnetic bodies using a bidirectional pulse driver circuit is shown. The method 500 is specifically directed to situations where the polarity of one or more soft magnetic bodies is to be reversed; therefore, occasional current pulses that do not reverse the polarity have little or no effect on the performance of the soft magnetic bodies or the system in which such magnetic bodies are integrated. The method 500 can be performed using a docking system such as that detailed with respect to FIG. 3 .

[0063] At block 510, a determination is made, such as by a controller device (e.g., a processor) or a component in communication with the controller, regarding the desired magnet polarity and the type of pulse that needs to be applied to the wire wrapped around the one or more soft magnetic bodies to achieve that polarity. The pulse type may be selected from a forward pulse or a reverse pulse.

[0064] At block 520, the potential of the load bias point of the circuit can be adjusted based on the determined pulse type or the desired magnet polarity. The potential of the load bias point can be adjusted to make the potential at the terminal of one or more magnets as close to the rail voltage as possible (e.g., 90% to 99% of the rail voltage) or as close to the ground potential as possible (e.g., 90% to 99% of the ground potential). The first SCR of one of the two pulse loop circuits can be triggered to adjust the load bias of one or more magnets. If a forward pulse is to be applied to one or more magnets, the first SCR is the SCR of the reverse pulse loop circuit; and if a reverse pulse is to be applied to one or more magnets, the first SCR is the SCR of the forward pulse loop circuit. The triggering of block 520 may involve applying a series of one or more pulses to trigger the first SCR one or more times. For example, in some embodiments, block 520 includes applying a pattern of 2 to 5 pulses to the first SCR to trigger it multiple times. When executing block 520, the second SCR remains disconnected so that no current actually passes through it.

[0065] The pulse of box 520 - which causes one or more relatively small current pulses to flow through the wire wrapped around one or more soft magnets (compared to box 540) - will have little effect on the performance of the magnets because the current may cause pulses in a direction that does not affect the polarity of the soft magnets.

[0066] At block 530, once the amount of current through the first SCR drops below a defined threshold, the first SCR enters a cutoff mode, causing the SCR to change from closed to open. As detailed with respect to block 520, the first SCR may be triggered multiple times; therefore, blocks 520 and 530 may be performed multiple times before proceeding to block 540.

[0067] At box 540, the second SCR is triggered to generate the current pulse determined at box 510. Box 540 can be performed immediately after box 530 (e.g., within 0.1 ms) to prevent the load bias point potential from returning substantially toward the midpoint between the rail voltage and the ground potential. If a forward current pulse is to be generated to achieve a first polarity, the second SCR is an SCR of a forward pulse loop circuit; if a reverse current pulse is to be generated so that a second polarity exists in a soft magnet, the second SCR is an SCR of a reverse pulse loop circuit. If the load bias point is set to a potential having a potential approximately equal to the rail voltage, triggering the SCR of the reverse pulse loop circuit causes a reverse current pulse to flow from the load bias point through the wire that is coiled around the magnet. If the load bias point is set to a potential having a potential approximately equal to the ground voltage potential, triggering the SCR of the forward pulse loop circuit causes a forward current pulse to flow through the wire that is coiled around one or more magnets to the load bias point.

[0068] Blocks 520 and 540 may be understood as time-varying pulse patterns applied by the controller to the first SCR and the second SCR. Thus, depending on the determined pulse type, the controller may output one of the two pulse patterns to the SCR or the intermediary trigger circuit, which in turn triggers the gates of the SCRs.

[0069] At block 550, the pulse of block 540 may cause the polarity of the one or more soft magnets to be reversed. The polarity may then remain in this state until a current pulse is applied in a direction opposite to the current pulse applied at block 540. This polarity adjustment may affect how the one or more soft magnets interact with other magnets, such as by attracting or repelling each other.

[0070] At block 560 , once the amount of current through the second SCR drops below a defined threshold, the second SCR enters a cutoff mode, causing the second SCR to change from closed to open.

[0071] At box 570, the processor may output a message, such as via a display or speaker, indicating the state of the device docking involving one or more soft magnets. For example, if adjusting the polarity of the soft magnet places the docking system in a mode in which the tablet can be easily removed from the base, the message may indicate that the tablet is ready to be removed. If adjusting the polarity of the soft magnet places the docking system in a mode in which the tablet is firmly attached to the base, the message may indicate that the tablet has successfully docked with the base. At this point, method 500 is complete and may be repeated at some future point in time when another current pulse may be applied to one or more magnets in the opposite direction to reverse the polarity again.

[0072] Figure 6 A graph 600 is shown of a forward current pulse applied to a load by a bidirectional pulse driver circuit. The forward current pulse may cause a large amount of current (such as between 300 amps and 400 amps) to be briefly driven through a load, such as a wire wrapped around one or more soft magnets. Such a high current may be required to reverse the polarity of the one or more soft magnets. The duration of the pulse may be between 10 μs and 50 ms; in one embodiment, the pulse duration is between 95 μs and 105 μs. The voltage potential applied to the wire wrapped around the one or more magnets may vary based on the number of soft magnets connected in series. For each magnet, it may be necessary to apply a potential between 20 V and 30 V; thus, if 8 to 10 magnets are connected in series, the applied potential may be between 160 V and 300 V.

[0073] In contrast, Figure 7 Graph 700 shows a reverse current pulse applied to a load by a bidirectional pulse driver circuit. Measured at the same points as the data of graph 600, graph 700 appears as a negative value because the current pulse flows through the load in the opposite direction. The reverse current pulse can cause a large amount of current (such as between 300 amps and 400 amps) to be briefly driven through a load, such as a wire wrapped around one or more soft magnetic bodies, in the opposite direction to the pulse of graph 600. Here again, the duration of the pulse can be between 10 μs and 50 ms; in one embodiment, the pulse duration is between 95 μs and 105 μs. (In Figure 7 , the current pulse becomes negative because it is in the opposite direction to the current pulse measured in graph 600).

[0074] Figure 8A graph 800 of a pattern of trigger pulses applied to a pair of silicon controlled rectifiers (SCRs) of a bidirectional pulse driver circuit is shown. The pulse pattern may be output by a controller directly to a pair of SCRs, or to a pair of trigger circuits, which in turn trigger the SCRs. In graph 800, two separate signals of 0 V to 5 V are shown for comparison. In graph 800, a first pattern output by the controller, in which SCR 226 is pulsed 810 and SCR 236 is pulsed 820, may result in a reverse pulse being applied to a load. Alternatively, in graph 800, a second pattern, in which SCR 236 is pulsed 810 and SCR 226 is pulsed 820, may result in a forward pulse being applied to a load. The specific number of pulses applied as part of pulse 810 may vary based on the embodiment, such as between one and ten.

[0075] It should be noted that the methods, systems and devices discussed above are intended to be examples only. It must be emphasized that various embodiments may omit, replace or add various programs or components as needed. For example, it should be understood that in alternative embodiments, the method may be performed in an order different from the order described, and various steps may be added, omitted or combined. In addition, in various other embodiments, the features described with respect to certain embodiments may be combined. Different aspects and elements of the embodiments may be combined in a similar manner. In addition, it should be emphasized that technology is constantly evolving, so many elements are examples and should not be interpreted as limiting the scope of the invention.

[0076] Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be appreciated by those of ordinary skill in the art that embodiments can be practiced without these specific details. For example, in order to avoid blurring the embodiments, known processes, structures and techniques have been shown without unnecessary details. This description only provides example embodiments and is not intended to limit the scope, applicability or configuration of the present invention. Instead, the foregoing description of the embodiments will provide an enabling description for implementing embodiments of the present invention for those skilled in the art. Various changes may be made to the functions and arrangements of elements without departing from the spirit and scope of the present invention.

[0077] In addition, it is worth noting that the embodiments can be described as processes depicted in flowcharts or block diagrams. Although each flowchart or block diagram can describe the operations as a sequential process, many operations can be performed in parallel or simultaneously. In addition, the order of the operations can be rearranged. The process can have additional steps not included in the figure.

[0078] Having described several embodiments, those skilled in the art will recognize that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the present invention. For example, the above elements may be merely components of a larger system, in which other rules may take precedence over or otherwise modify the application of the present invention. In addition, some steps may be taken before, during, or after considering the above elements. Therefore, the above description should not be considered to limit the scope of the present invention.

Claims

1. A bidirectional pulse driver circuit, comprising: Positive pulse trigger circuit; A forward pulse loop circuit, wherein the forward pulse loop circuit is connected to a load, wherein: The forward pulse loop circuit includes a first silicon controlled rectifier (SCR) activated by the forward pulse trigger circuit; Reverse pulse trigger circuit; A reverse pulse loop circuit, the reverse pulse loop circuit is connected to the load, wherein: The reverse pulse loop circuit includes a second SCR activated by the reverse pulse trigger circuit; and A controller, the controller communicating with the forward pulse trigger circuit and the reverse pulse trigger circuit, wherein: The controller activates the forward pulse trigger circuit and the reverse pulse trigger circuit in a first mode so that a current pulse is applied to the load in a first direction; and The controller activates the forward pulse trigger circuit and the reverse pulse trigger circuit in a second mode so that the current pulse is applied to the load in a second direction.

2. The bidirectional pulse driver circuit of claim 1, wherein: The forward pulse loop circuit includes a first capacitor; A first terminal of the first capacitor is connected to an anode of the first SCR; and A second terminal of the first capacitor is connected to a terminal of the load.

3. The bidirectional pulse driver circuit of claim 2, wherein: The reverse pulse loop circuit includes a second capacitor; The first terminal of the second capacitor is connected to the cathode of the second SCR; and A second terminal of the first capacitor is connected to the terminal of the load and the second terminal of the first capacitor.

4. The bidirectional pulse driver circuit of claim 1, wherein the first mode comprises activating the reverse pulse trigger circuit multiple times and then activating the forward pulse trigger circuit.

5. The bidirectional pulse driver circuit of claim 4, wherein the second mode comprises activating the forward pulse trigger circuit multiple times and then activating the reverse pulse trigger circuit.

6. The bidirectional pulse driver circuit of claim 5, further comprising the load, wherein the load comprises a wire coiled around one or more soft magnetic bodies.

7. The bidirectional pulse driver circuit of claim 6, wherein the polarity of the one or more soft magnetic bodies flips based on the direction of the current pulse.

8. The bidirectional pulse driver circuit of claim 7, further comprising a tablet system comprising a tablet computer and a base.

9. The bidirectional pulse driver circuit of claim 8, wherein: The one or more soft magnetic bodies, the forward pulse trigger circuit, the forward pulse loop circuit, the reverse pulse trigger circuit, and the reverse pulse loop circuit are included as part of the base.

10. The bidirectional pulse driver circuit of claim 9, wherein the tablet computer is configured to output an indication that the tablet computer and the base are ready to be separated based on whether the controller activates the first mode or the second mode.

11. A method for reversing the polarity of a soft magnetic body using a bidirectional pulse driver circuit, the method comprising: determining a desired polarity of the soft magnetic body; Based on the desired polarity, adjusting the potential of the load bias point by triggering a first silicon controlled rectifier (SCR); After triggering the first SCR, allowing the first SCR to achieve low current shutdown; as well as Based on the desired polarity, a second SCR is triggered to apply a current pulse to a load, wherein the current pulse changes the polarity of the soft magnetic body to the desired polarity.

12. The method of claim 11, further comprising: determining a second desired polarity of the soft magnetic body; adjusting the potential of the load bias point by triggering the second SCR based on the second desired polarity; After triggering the second SCR, allowing the second SCR to achieve low current shutdown; as well as Based on the second desired polarity, the first SCR is triggered to apply a second current pulse to the load in an opposite direction of the current pulse, wherein the second current pulse changes the polarity of the soft magnetic body to the second desired polarity.

13. The method of claim 11, wherein the load comprises a wire coiled around the soft magnetic body.

14. The method of claim 11, wherein triggering the first SCR and the second SCR is performed according to a first defined pattern or a second defined pattern based on the desired polarity.

15. The method of claim 14, wherein a controller triggers the first SCR via a first trigger circuit and triggers the second SCR via a second trigger circuit.

16. The method of claim 11, wherein the current pulses are generated using charge stored in one or more capacitors.

17. The method of claim 11, wherein the first SCR and the second SCR are part of a circuit integrated into a tablet docking system.

18. The method of claim 17, further comprising: After the second SCR is triggered, a message indicating the status of the tablet docking is output for presentation by a display of the computerized tablet of the tablet docking system.

19. A tablet docking system, comprising: computerized tablet; a docking station, the computerized tablet docking on the docking station; as well as A bidirectional pulse driver circuit, the bidirectional pulse driver circuit comprising: Positive pulse trigger circuit; A forward pulse loop circuit connected to a load comprising a wire wound with a soft magnetic body, wherein: The forward pulse loop circuit includes a first silicon controlled rectifier (SCR) activated by the forward pulse trigger circuit; Reverse pulse trigger circuit; A reverse pulse loop circuit, the reverse pulse loop circuit is connected to the load, wherein: The reverse pulse loop circuit includes a second SCR activated by the reverse pulse trigger circuit; and A controller, the controller communicating with the forward pulse trigger circuit and the reverse pulse trigger circuit, wherein: The controller activates the forward pulse trigger circuit and the reverse pulse trigger circuit in a first mode so that a current pulse is applied to the load in a first direction to set the polarity of the soft magnetic body; and The controller activates the forward pulse trigger circuit and the reverse pulse trigger circuit in a second mode so that the current pulse is applied to the load in a second direction to set the polarity of the soft magnetic body opposite to the first mode.

20. The tablet docking system of claim 19, wherein the polarity of the soft magnetic body associated with the first mode allows the computerized tablet to be more easily removed from the docking station than the polarity of the soft magnetic body associated with the second mode.

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