MOMENTARILY ENABLED ELECTRONIC DEVICE

• US 20090315411A1
• Filed: 06/18/2008
• Published: 12/24/2009
• Est. Priority Date: 06/18/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Depew, John M.
• Granted Patent: US 8,063,625 B2
• Time in Patent Office: Days
• US Class Current: 307/141
• CPC Class Codes: H03K 17/28 Modifications for introducing a time delay before switching modifications to provide a choice of time-intervals for executing more than one switching action H03K17/296
• CPC Class Codes: H03K 19/0016 by using a control or a clock signal, e.g. in order to apply power supply

Abstract

A circuit or apparatus for providing intermittent or interruptible power to an electronic device. The circuit may provide power upon user initiation and interrupt that power in response to a user command, fault state, period of inactivity and so forth. As one example, interruptible power may be initially provided to activate or “power up” an electronic device and constant power provided after the initial activation. The initial powering up of the device may be facilitated by closing two contacts. The circuit may continue to provide power after the button is released through a monitoring and/or feedback mechanism.

Claims

1. An apparatus for transmitting power, comprising:

a power input;

an activating element connected to the power input;

a power converter comprising a first input, second input and output, the power converter connected to the power input at the first input;

a voltage source connected to the second input by a central node; and

a gate device connected between the output and the central node.

2. The apparatus of claim 1, further comprising a monitor connected to the activating element, the output and an input of the gate device.

3. The apparatus of claim 2, wherein:

the monitor is operative to sense an operating state of the activating element; and

the monitor is further operative to sense at least one of an output voltage and output current present on the output.

4. The apparatus of claim 3, wherein:

the gate device comprises a transistor; and

in the event the monitor senses the operating state of the activating element is open and the output conducts at least one of an output voltage and an output current, energizing the transistor, thereby permitting a transistor current to flow from a second terminal of the transistor to a third terminal of the transistor.

5. The apparatus of claim 4, wherein, when the transistor is energized, the transistor current flows from the output to the central node.

6. The apparatus of claim 3, further comprising a diode connected between the activating element and the central node.

7. The apparatus of claim 6, wherein:

the gate device is a button;

the voltage source is a capacitor; and

when the button is pressed, the diode permits a charging current to flow from the power source to the central node and through the capacitor, thereby at least partially charging the capacitor.

8. The apparatus of claim 7, wherein:

when a voltage of the central node equals or exceeds a shutdown voltage, the power converter is operative; and

when the voltage of the central node is less than the shutdown voltage, the power converter is inoperative.

9. The apparatus of claim 1, wherein the power input and monitor are intermittently connected to the activating element.

10. The apparatus of claim 1, wherein the monitor comprises a microcontroller.

11. A method for supplying power to a device, comprising the operations of:

closing a contact;

in response to closing the contact, activating a power converter;

in response to activating the power converter, supplying an output voltage;

raising a voltage of a node above a shutdown voltage; and

maintaining the output voltage so long as the node voltage exceeds the shutdown voltage.

12. The method of claim 11, wherein the output voltage charges a capacitor connected to the node.

13. The method of claim 11, wherein the operation of raising a voltage of a node above a shutdown voltage comprises:

activating a transistor, thereby permitting the voltage of the node to approximately equal the output voltage.

14. The method of claim 13, wherein the operation of activating the transistor comprises:

determining the contact is open;

detecting the output voltage; and

in response to both determining the contact is open and detecting the output voltage, activating the transistor.

15. The method of claim 14, wherein the operation of, in response to closing the contact, activating a power converter comprises:

supplying power from a power source to a capacitor, thereby at least partially charging the capacitor; and

maintaining, via the capacitor, the node voltage above the shutdown voltage at least until the transistor is activated.

16. The method of claim 11, further comprising the operations of:

opening the contact;

closing the contact a second time for at least a minimum time; and

after the minimum time, deactivating the transistor.

17. The method of claim 11, further comprising the operations of:

opening the contact;

closing the contact a second time for at least a minimum time; and

after the minimum time, initiating a function associated with the device.

18. A method for supplying power to a device, comprising the operations of:

detecting a button has been pressed;

detecting an output voltage from a power converter;

detecting the button has been released; and

in response to detecting the button has been released and detecting the output voltage, supplying a base voltage to a base of a transistor, thereby creating a current path through the transistor and maintaining the output voltage of the power converter.

19. The method of claim 18, further comprising the operations of:

detecting a fault condition; and

in response to detecting the fault condition, ceasing to supply the base voltage, thereby terminating the output voltage of the power converter.

20. The method of claim 19, wherein the fault condition is a lack of user input to the device.