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EP-4402802-B1 - RESET DEVICE

EP4402802B1EP 4402802 B1EP4402802 B1EP 4402802B1EP-4402802-B1

Inventors

  • LILIENTHAL, HEIKO

Dates

Publication Date
20260506
Application Date
20220825

Claims (15)

  1. A reset device (100) for resetting a controller (201) of a motor (202), the device comprising: a first delay circuit (101) configured to discharge a first voltage (U1(t)) at a first rate (R1); a second delay circuit (102) configured to discharge a second voltage (U2(t)) at a second rate (R2), wherein the first rate is slower than the second rate; and a reset circuit (103) configured to provide a reset signal to the controller; wherein the first delay circuit (101) and second delay circuit (102) are arranged to be charged from a physical connector (300), and to discharge upon removal of the physical connector; the first delay circuit (101) triggers the reset circuit to provide the reset signal when the first voltage meets a first threshold condition relative to the second voltage; the maximum value of the first voltage stored by the first delay circuit (101) is less than the maximum value of the second voltage stored by the second delay circuit (102); and the first threshold condition is that the first voltage exceeds the second voltage by a minimum amount.
  2. The reset device of claim 1, wherein the reset device comprises a first switching element (104) switchably connecting the first delay circuit (101) to the reset circuit, wherein the first switching element is configured to connect the first delay circuit (101) to the reset circuit only if the first voltage meets the first threshold condition.
  3. The reset device (100) of claim 2, wherein the first switching element is a first transistor (T1) gated by the second delay circuit (102) such that the first delay circuit (101) is connected to the reset circuit when the first threshold condition is met.
  4. The reset device (100) of any preceding claim, wherein the reset circuit is configured to provide the reset signal to the controller only when the first voltage meets a second threshold condition.
  5. The reset device (100) of claim 4, wherein the reset circuit comprises a second switching element (105) configured to switchably connect the controller to a reset voltage, wherein the second switching element is configured to connect the controller to the reset voltage when the first voltage meets the second threshold condition.
  6. The reset device (100) of claim 5, wherein the reset voltage is low, ground, or 0V.
  7. The reset device (100) of claim 5 or claim 6, wherein the second threshold condition is that the first voltage is greater than a fixed amount.
  8. The reset device (100) of claim 7, wherein the second switching element is a second transistor (T2) gated by the first delay circuit (101), and wherein the second threshold condition is that the first voltage is greater than a gate voltage of the second transistor.
  9. The reset device (100) of any preceding claim, wherein the first delay circuit (101), the second delay circuit (103-2) and/or the reset circuit are formed of analogue components.
  10. The reset device (100) of claim 9, wherein the first delay circuit (101) and/or second delay circuit (102) comprises an RC circuit.
  11. The reset device (100) of any preceding claim, wherein the reset circuit is a first reset circuit for providing a reset signal to a first controller, and wherein the reset device further comprises a second reset circuit (103-2) for providing a reset signal to a second controller (201), wherein the first delay circuit (101) is configured to trigger the first reset circuit and second reset circuit (103-2) to provide the respective reset signals when the first voltage meets a first threshold condition relative to the second voltage; wherein, optionally, the second reset circuit (103-2) is configured to provide the respective reset signal to the second controller only if the first voltage meets a third threshold condition.
  12. The reset device (100) of any preceding claim, wherein the physical connector is a USB connector.
  13. A motor assembly (200) comprising: a motor (202); a controller for controlling the motor; a port (203) for receiving a voltage-supplying physical connector; and a reset device according to any of claims 1-12 arranged to receive a voltage from a physical connector received in the port, and to provide a reset signal to the controller.
  14. The motor (202) of claim 13, further comprising a battery for powering the motor, wherein the battery is arranged to be charged by a physical connector received in the port.
  15. A motorised blind (400) comprising the motor assembly of claim 13 or claim 14.

Description

The present application relates to a reset device for resetting a controller of a motor, and to a motor assembly comprising a reset device. It is sometimes necessary for a controller of a device such as a motor to be reset, for example in the event of software or firmware malfunctions. Where the device is powered by a permanently installed battery, the user needs the option to manually trigger a reset of the controller. Additionally, such devices may be supplied in a sleep state to conserve power, which requires a reset signal to transition into an operating state. Conventionally resetting is achieved by providing a physical reset button for the user to press. However, this requires physical space for a button on the outer casing of the product into which the motor is incorporated. For products such as motorised blinds the available space may be limited. Furthermore, a physical button typically requires a long reset line, which may be vulnerable to external electromagnetic signals. There is therefore a need for an alternative approach to resetting controllers of motors. US 2005/231874 A1, WO 2020/133246 A1, CN 204 697 033 U and CN 112 072 746 A disclose background art. In accordance with a first aspect of the invention there is provided a reset device for resetting a controller of a motor, the device comprising: a first delay circuit configured to discharge a first voltage; a second delay circuit configured to discharge a second voltage; and a reset circuit configured to provide a reset signal to the controller; wherein the first delay circuit and second delay circuit are arranged to be charged from a physical connector, and to discharge upon removal of the physical connector; and wherein the first delay circuit triggers the reset circuit to provide the reset signal when the first voltage meets a first threshold condition relative to the second voltage. Such a device enables a reset of the controller (e.g. microcontroller) to be triggered by insertion and removal of a physical connector, such as a USB connector. This avoids the need for a physical reset button, whilst still providing the user with the ability to manually trigger a reset of the controller. The physical connector is preferably the same physical connector used to charge an internal battery powering the motor, reducing the physical space required on the outside of the product incorporating the motor. This also means that the reset pulse is triggered when the battery has just been charged, providing a stable charge for the resetting of the controller. Furthermore, as the reset device can be located close to the controller, the reset line can be shorter than may be possible for a physical reset button. This provides greater EMC protection. Further advantageously, such a reset device can be constructed of only analogue components. The trigger for the reset pulse is provided by the varying voltages output by the first and second delay circuits. The first and second voltages output by the delay circuits drop in response to the removal of the charging voltage from the physical connector. No digital components are required to provide the varying voltages or trigger the reset pulse, and no additional voltage lines are needed to power the first and second delay circuits. Using analogue components simplifies the circuit design, and draws less energy from the battery than would be required by digital components. As used herein, the term circuit includes both a complete circuit and parts of a larger circuit performing a particular function, such as the first delay circuit and second delay circuit. In some embodiments the reset device comprises a first switching element switchably connecting the first delay circuit to the reset circuit, wherein the first switching element is configured to connect the first delay circuit to the reset circuit only if the first voltage meets the first threshold condition. The first switching element may be a first transistor gated by the second delay circuit such that the first delay circuit is connected to the reset circuit when the first threshold condition is met. In particular the first transistor may be a MOSFET, such as a p-type MOSFET. Such a transistor allows the first threshold condition to be implemented with a single, analogue component. The first threshold condition is that the first voltage exceeds the second voltage by a minimum amount. The minimum amount may be a hysteresis voltage of the first switching element, such as a hysteresis voltage of the first transistor. In some embodiments, the reset circuit is configured to provide the reset signal to the controller only when the first voltage meets a second threshold condition. The second threshold condition may be that the first voltage is greater than a fixed amount. In this way, the reset device is able to both trigger and stop a reset signal. In other words, the reset device can trigger a reset pulse. The length of the reset pulse can be selected as desired by