The present disclosure relates to a method and system for detecting the orientation of a secondary device electrically connected to a primary device, where the secondary device can connect to the primary device in a plurality of orientations. The invention relates in particular to charging a secondary device from a primary device, and to charging of devices with a plurality of symmetrically disposed electrical contacts that can mate with a charging device in a plurality of different orientations.

Portable electronic devices often need to electrically connect to other electrical devices in order to be recharged and in order to exchange data, such as software updates or usage data. Typically data is transferred over one set of electrical contacts and power is transferred over another set of electrical contacts.

In order to ensure that the correct electrical connections are made, so that the data contacts on one device mate with the data contacts on the other device, and similarly the power contacts on one device mate with the power contacts on the other device, prior systems have relied on mechanical means to prevent incorrect connection. This means that the devices can only connect in one orientation, which can be difficult and cause irritation for end users.

In some systems it may be advantageous to allow the secondary device to connect to the primary device in some orientations, but to prevent, or at least make difficult, connection in other orientations using mechanical means. In such systems it may still be possible for users to force the secondary device into engagement with the primary device in an undesirable configuration, which could cause damage to the primary or secondary device.

It is an object of the invention to allow power and data contacts on two devices to be correctly mated together in a plurality of mechanically allowed orientations but to able to prevent electrical operation in orientations that are not mechanically allowed.

In a first aspect there is provided an electrical system comprising a primary device and a secondary device configured to be electrically connected to one another, wherein the primary device comprises six electrical contact pins within a socket and the secondary device comprises five electrical contacts on a contact end of the secondary device, the five electrical contacts comprising a power input contact, a data reception contact, a data transmission contact and two electrical ground contacts, and wherein the socket and contact end of the secondary device are constructed to allow the electrical contact pins on the primary device to be connected to the electrical contacts on the secondary device in ten different relative orientations, wherein to move from each orientation to an adjacent relative orientation the secondary device is rotated relative to the primary device, and wherein the system is constructed so that five adjacent relative orientations are electrically distinct from the remaining five relative orientations.

The primary device is advantageously able to reconfigure the function of each of the electrical contact pins dependent on the relative orientation of the secondary device. The primary device is advantageously able to reconfigure the function of each of the electrical contact pins to operate when the secondary device is in one of the five adjacent relative orientations. The primary device may be configured so as not to operate when the secondary device is not in one of the five adjacent relative orientations. In this way, a system in accordance with the present invention is able to prevent electrical operation of the device if the primary and secondary devices are not in a mechanically desirable relative orientation.

The secondary device may be an electrically operated smoking device and may be sized to approximate the size of a conventional cigarette. The primary device may be a charger device or an adaptor allowing the secondary device to connect to a further device and exchange power and data with the further device. For example, the primary device may be a USB adaptor for the secondary device.

Advantageously, in each of the ten relative orientations, each electrical contact on the secondary device is connected to a single contact pin on the primary device, and one contact pin on the primary device is not in contact with an electrical contact on the secondary device.

The secondary device may have an external housing having a cross section in the shape of a regular polygon with protrusion on at least one side of the polygon. The primary device may comprise a bearing surface wherein in the five adjacent orientations the protrusion is clear of the bearing surface but in the remaining five orientations the protrusion interferes with the bearing surface. In one embodiment, the polygon is a decagon. In one embodiment the bearing surface is a surface extending from an edge of the socket having the shape of one half of the socket and is configured to support the secondary device when it is engaged with the socket.

The electrical contact pins in the socket of the primary device may be disposed in the shape of an irregular hexagon. The electrical contacts on the secondary device may be disposed in the shape of a regular pentagon.

Four of the contact pins in the socket of the primary device may have an associated switch allowing connection of those pins to a power supply line in the primary device but the primary device may be constructed so that the remaining two contact pins in the socket of the primary device cannot be connected to the power supply line.

Each of the contacts may span two adjacent sides of a housing of the secondary device. So in the case of five electrical contacts, the secondary device may have a ten sided housing, with each contact spanning two sides of the housing.

The primary device may comprise a controller configured to apply a current to different pairs of electrical contact pins and measure the voltage between each pair of electrical contact pins and a non-volatile memory that stores a voltage record, wherein the controller is configured to compare measured voltages between the different pairs of electrical contacts with the voltage record. By using a power source in the primary device and measuring the voltage drop across the plurality of pairs of contacts to determine the relative orientation of the primary and secondary devices, no power is required from within the secondary device. So the system can operate even if the secondary device has no available power, for example because a battery in the secondary device has become fully discharged. Any suitable switches may be used, but in one embodiment each of the switches is a transistor.

The primary device may be a charging device configured to charge a secondary battery in the secondary device. The controller in the primary device may be configured to close a plurality of the switches in response to the determined orientation of the secondary device prior to a charging operation. The primary device may further comprise a current limiting resistor connected in parallel with a current limiting switch between a power source and the electrical contacts on the device, wherein the controller is configured to hold the current limiting switch open during an orientation determination operation. This ensures that only limited current is passed to the secondary device contacts during the orientation determination operation but that a greater current can be passed to the secondary device during a charging operation.

It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented or supplied or used independently.

These and other aspects of the apparatus will become apparent from the following exemplary embodiments that are described with reference to the following figures in which:

Figure 1 is a perspective illustration of an exemplary secondary device;

Figure 2 is schematic illustration of the secondary device of Figure 1 ;

Figure 3a is an illustration of the layout of the electrical contacts on an end face of the secondary device of Figure 2;

Figure 3b is an illustration of the layout of the electrical contacts on the primary device of Figure 1 overlaid on the illustration of Figure 3a;

Figure 4a is a perspective view of an exemplary primary device;

Figure 4b is a schematic illustration of the primary device of Figure 4a coupled to a secondary device;

Figure 4c illustrated the layout of the contact pins in the secondary device;

Figure 5 is a schematic illustration of the allowed orientations of the secondary device relative to the primary device;

Figure 6 is an illustration of an arrangement for determining the orientation of the secondary device; and

Figure 7 illustrates an arrangement of switches within the primary device.

Figure 1 shows a perspective view of one embodiment of a secondary device 100. The secondary device 100 in this example is an electrically heated aerosol-generating device adapted to receive a smoking article comprising an aerosol-forming substrate. The device 102 is elongate and comprises two opposed polygonal end faces 102 and 104 respectively. As can be seen, the outer housing of the device 100 comprises four portions joined at the coupling lines 108, 1 10 and 1 12 respectively. The four portions respectively are a first tapered end portion 1 14 attached to a first central portion 1 16, a second tapered end portion 120 attached to a second central portion 1 18. A button 106 is provided on the housing in a protruding portion, which as a keying feature limiting the number of possible orientations in which the secondary device can engage the primary device.

The secondary device is illustrated schematically in Figure 2. The secondary device 102 comprises a rechargeable battery 126, secondary control electronics 128 and electrical contacts 130. As described above, the rechargeable battery 126 of the secondary device 102 is configured to receive a supply of power from the primary battery 106 when the electrical contacts 130 are in contact with the electrical contacts 1 10 of the primary device 100 and the lid is in the closed position. The secondary device 102 further comprises a cavity 132 configured to receive the aerosol generating article 101. A heater 134, in the form of, for example, a blade heater, is provided at the bottom of the cavity 132. In use, the user activates the secondary device 102, and power is provided from the battery 126 via the control electronics 128 to the heater 134. The heater is heated to a standard operational temperature that is sufficient to generate an aerosol from the aerosol-forming substrate of the aerosol-generating article 104. The components of the secondary device 102 are housed within the housing 136. Button 106 is also illustrated in Figure 2.

Figure 4a shows a primary device 400. The primary device 400 in this example is a charging unit for a secondary device of the type illustrated in Figures 1 and 2. The primary device 400 is a USB charging device configured to connect to the USB port of a personal computer. The primary device comprises a USB connector 444 connected to the housing 440 of the primary device by a cable 442. Power is supplied to the primary device through the USB connection. The primary device comprises, a charger circuit, control electronics, and electrical contacts configured to provide electrical power to the secondary device, from the charger circuit, when the secondary device is in connection with the electrical contacts, as will be described.

Figure 4b shows a cross section of the primary device with a secondary device engaged with it. As can be seen, the electrical contact pins 402, 404, 406 on the primary device are provided within a socket 450. Although only three contact pins are visible in Figure 4b, there are six pins and their layout is illustrated in Figure 4c. The socket 450, together with opening 446, is configured to receive the secondary device 100. A bearing surface 452 supports the secondary device. The bearing surface is shaped to correspond with half of the surface of the secondary device or one half of the socket, i.e. half of a deacagon. The upper extent of the bearing surface is indicated by dotted line 454. When the secondary device is electrically engaged with the primary device, a flat surface of the housing of the secondary device rests on the bearing surface 452. But the interaction of the bearing surface 452 on the primary device and the button 106 on the secondary device prevents the secondary device from engaging with the electrical contact pins in some orientations. The primary device is configured to supply power to the secondary device, and to exchange data with the secondary device through the contact pins. The data connection is configured to download data from the secondary device such as usage statistics, operational status information and the like. In addition, the data connection is configured to upload data from the primary device to the secondary device such as operating protocols. The operating protocols may include power supply profiles to be used when supplying power from the secondary power supply to the heater. Data may be communicated from the secondary device 100 to the primary device 400 and stored in, for example, control electronics in the primary device. Data may then be communicated out of the primary device 400 via the USB connector. The primary device can be switched between different configurations such that contact pins in the primary device perform different functions in different configurations, as will be described.

Figure 4c illustrates the layout of the contact pins 402, 404, 406, 408, 410, 412 in the socket of the primary device. It can be seen that each of the pins is equally spaced from a central point but that their angular spacing around that central point is not equal. Pins 402, 404 and 406 are spaced from each other by an angle of 54°. Pin 408 is spaced from pin 406 by an angle of 72°. Pins 408, 410 and 412 are spaced from each other by 54°. And pin 402 is spaced from pin 412 by an angle of 72°.

Figure 3a shows the polygonal end face 102 of the secondary device 100. As can be seen, the polygon in this embodiment is a decagon. The button 106 protrudes beyond the basic decagonal shape. Figure 3a shows that the end face 102 has five electrical contacts 302, 304, 306, 308 and 310, each spanning two adjacent sides of the decagonal housing. The electrical contacts are disposed in a rotationally symmetric pattern about a central axis of the secondary device. The electrical contacts are adapted to connect with the contact pins in the primary charging device 400. Contact 302 is the power input contact, contact 304 is an electrical ground contact, contact 306 is a data transmission contact, contact 308 is a redundant contact also connected to electrical ground and contact 310 is a data reception contact.

Figure 3b shows the end face of the secondary device with the position of the electrical contact pins of the primary device superimposed. There are six pins 402, 404, 406, 408, 410, 412. It can be seen a different pin is in contact with a different electrical contact on the secondary device and one pin is positioned between contacts on the secondary device and so does not make an electrical connection. The configuration of the electrical contact pins and the electrical contacts means that this is true in all possible positions.

The primary device is constructed to allow five of the six pins to be connected to each of: the power output from the charging system, electrical ground, and the data reception and data transmission ports of the CPU in the primary device, depending on the orientation of the secondary device in the primary device. The end user can insert the secondary device into the socket in the primary device in any of the mechanically allowed orientations without needing to worry about the correct electrical configuration. One of the pins on the primary device is redundant and makes no electrical connection with the secondary device, but which pin is redundant depends on the orientation of the secondary device.

In one example there are five mechanically allowed orientations, shown in Figure 5 and labelled P1 , P2, P3, P4 and P5, because five orientations are prevented by the interaction of the button 106 and the bearing surface 452. Each allowed orientation is rotated 36° from the adjacent mechanically allowed orientations. Figure 5 illustrates the allowed orientations. The position of each of the contact pins 402, 404,406, 408, 410 and 412 on the primary device is shown for each allowed orientation. Each of the electrical contacts 302, 304, 306, 308, 310 is shown and line 360 represents the position of the button. It can be seen that either pin 404 or pin 410 lies between electrical contacts on the secondary device, depending on the relative orientation of the primary and secondary devices. The button cannot be below the horizontal because in those orientations it would interfere with the bearing surface, so there are five no-allowed, or mechanically undesirable, orientations.

However, it may still be possible for a user to force the secondary device into one of the non-allowed orientations, placing the primary and secondary devices under mechanical stress and potentially causing damage to the primary or secondary device. But the configuration of the contact pins in the primary device allows for non-allowed orientations to be electrically detected. The primary device is configured not to operate if a non-allowed orientation is detected.

Figure 6 illustrates an arrangement that allows the primary device to determine the orientation of the secondary device. In this example, because the primary device is a charger, it is possible that the secondary device will have no power. So it is advantageous if the detection orientation process uses a power source in the primary device rather than a power source in the secondary device to perform detection. In the system shown in Figure 6, it is the position of the ground contacts on the secondary device that are detected.

Figure 6 is a schematic illustration of the contact pins 402, 404, 406, 408, 410, 412 on the primary device connected to the contacts on the secondary device 100. Contacts, 402, 404 and 406, which may be connected to power contact 302 in one of the allowed orientations, are connected the power input line Vcc in the primary device through resistor 602 and through a corresponding switch 610. Contact pins 408 and 410 are connected to ground through switches 612. Contact pin 412 is also connected to Vcc through a switch 610. In this embodiment switches 610 and 612 are transistors which are controlled by the CPU 606. A second resistor 604 is provided between the first resistor 602 and electrical ground, to form a voltage divider. The CPU 606 is configured to read the voltage between the two resistors when each of pins 402, 404, 406 and 412 is connected to Vcc.

The orientation process proceeds to determine which of pins 410, 402, 404 and 412 is connected to electrical ground in the secondary device. In a first stage, S1 , switches associated with contact pins 402 and 408 are closed. The voltage from the voltage divider is then recorded. Then in stage S2 the switches associated with pins 404 and 410 are closed and the voltage at the voltage divider recorded. In stage S3 the switches associated with pins 406 and 412 are closed and the voltage at the voltage divider recorded. In stage S4 the switches associated with pins 412 and 410 are closed and the voltage at the voltage divider recorded. The recorded voltages either have a non-zero value, represented by x in the table below, or are zero, indicating that the pin 402, 404 or 406 is connected to ground. Table 1 below shows the resulting voltages depending on the actual orientation of the secondary device.

Table 1

It can be seen that each distinct electrical configuration corresponding to a particular orientation or orientations of the secondary device relative to the primary device has a unique result from stage S1 , S2, S3, S4 and S5. The CPU can compare the recorded result with a database stored in memory to deduce the correct electrical configuration for the contact pins.

Once the orientation of the secondary device relative to the primary device is known, the primary device must then configure to contact pins to connect them to the correct function within the primary device. Figure 7 is a simplified diagram showing the arrangement of switches in the primary device that allows the correct configuration to be achieved.

The power source, indicated by Vcc, may need to connect pins 402, 404 and 406 depending on the orientation of the secondary device. Accordingly switches 610 are provided to selectively connect the Vcc to one of these pins. Pin 412 may connected to Vcc during an orientation detection operation and so is provided with a switch 610. All of the pins 402, 404, 406, 408 and 410 may need to be able to connect to electrical ground depending on the orientation of the secondary device. Accordingly switches 612 are provided between each of the pins and electrical ground. The data transmission line, indicated by Tx may need to connect to pin 402, 404 or 412. The data receiving line Rx may need to connect to pin 406, 408, 410 or 412. A first tri-state switch 802 is provided to selectively connect Tx to pin 402 or 404 or neither. A second tetra-state switch 804 is provided to connect Rx to pin 406, 408, 410 or none. A third tri-state switch 806 is also provided to connect pin 412 to Tx or Rx or neither. In this example each of the switches 610 and 612 is a MOSFET. Operation of each switch is controlled by CPU in the primary device. The primary device may store the correct configuration of switches 610, 612, 802, 804 and 806 for each determined orientation of the secondary device in a non-volatile memory. In response to a determined orientation, the CPU can then look-up the switch configuration from the memory and control the switches accordingly.

A current limiting resistor 810 is also provided to ensure that only limited current is used in the orientation detection process. A shorting switch 812, which is also a transistor, is provided for shorting out the current limiting resistor during a charging process. The shorting switch is also controlled by the CPU.

Because of the layout of the electrical contact pins in the primary device in the allowed orientations it must be pin 402, 404 or 406 connected to Vcc to allow charging of the secondary device. If the secondary device is forced into non-allowed orientation then it would need to be pin 408, 410 or 412 connected to Vcc in order to charge the secondary device. So none of the allowed orientations is electrically equivalent to any of the non-allowed orientations. The primary device can be configured never to allow pin 408, 410 or 412 to be connected to Vcc during a charging operation. So whenever the current limiting resistor 810 is shorted the CPU ensures that the switch 610 that could connect pin 412 to Vcc is kept open. Pins 408 and 410 cannot be electrically connected to Vcc. This ensures that the primary device does not operate to charge the secondary device when the secondary device is incorrectly inserted into the socket of the primary device.

The described embodiment is just one example of many possible embodiments that could implement the invention. It is of course to be understood that the specification is not intended to be restricted to the details of the above embodiments which are described by way of example only. Although the invention has been described in relation to an electrically heated smoking system comprising a smoking device and a charging device, it should be clear that any primary and secondary devices that exchange power and data over different electrical contacts could be used to implement the invention.