TAMPER SWITCH ACTIVATION WITHOUT POWER

• US 20120223836A1
• Filed: 03/03/2011
• Published: 09/06/2012
• Est. Priority Date: 03/03/2011
• Status: Active Grant

• Current Assignee: Assa Abloy AB
• Original Assignee: Assa Abloy AB
• Inventors: Moller, Per Kristian
• Granted Patent: US 9,777,510 B2
• Time in Patent Office: Days
• US Class Current: 340/540
• CPC Class Codes: E05B 2047/0058 by batteries
• CPC Class Codes: E05B 39/00 Locks giving indication of authorised or unauthorised unlocking with key identification means E05B35/001; alarm locks E05B45/00
• CPC Class Codes: E05B 47/00 Operating or controlling locks or other fastening devices by electric or magnetic means electric permutation locks E05B49/00
• CPC Class Codes: E05B 65/0075 for safes, strongrooms, vaults, fire-resisting cabinets or the like safes, closures and fastenings therefor E05G
• CPC Class Codes: E05G 1/005 Portable strong boxes, e.g. which may be fixed to a wall or the like E05G1/08, E05G1/14 take precedence; devices to prevent theft or loss of bags, trunks, baskets, or the like A45C13/18; coin boxes for coin freed apparatus G07F9/06
• CPC Class Codes: E05G 1/04 Closure fasteners locks E05B

Abstract

A tamper-detection device and system are disclosed. The tamper-detection device includes one or more components which enable the tamper-detection device to detect a state change, even in the absence of a power supply. A capacitor is provided in the tamper-detection device that, when shorted, discharges and induces a state change at a microcontroller of the tamper-detection device.

Claims

1. A method, comprising:

providing a tamper-detection device with a tamper switch, a microcontroller, a diode and a capacitor connected in parallel with the tamper switch such that closing of the tamper switch in the absence of power supplied to the microcontroller causes the capacitor to discharge and change an input value provided to the microcontroller.

2. The method of claim 1, wherein the input value is read by the microcontroller after power is reapplied to the microcontroller.

3. The method of claim 1, wherein the microcontroller is further configured to activate a tamper function upon reading an input value which indicates the switch has moved from a normally open position to a closed position.

4. The method of claim 3, wherein the microcontroller is further configured to disable at least some functionality of a device equipped when the microcontroller recognizes activation of the tamper function.

5. The method of claim 4, wherein upon at least some functionality of the device being disabled, displaying a message or signal relating to the disabled functionality.

6. The method of claim 4, wherein the device is a safe and the microcontroller disables the locking mechanism such that the safe cannot be locked.

7. The method of claim 4, wherein the device is a door lock and the microcontroller disables the locking mechanism so that the door cannot be unlocked or locks the door.

8. The method of claim 1, wherein the capacitor prevents the change of an input at the microcontroller relating to the status of the tamper switch during a loss of power event provided the capacitor has a charge and the tamper switch is not physically activated.

9. The method of claim 1, wherein loss of charge of the capacitor, whether or not the tamper switch is closed, causes change in an input value to the microcontroller.

10. A tamper-detection device, comprising:

a tamper switch moveable between a first position and a second position, wherein the first position corresponds to a normal position of the tamper switch and the second position corresponds to a tamper-detected position;

a microcontroller connected to the tamper switch, wherein the microcontroller is configured to receive an input that indicates whether the tamper switch is in the first position or the second position; and

a capacitor connected between the tamper switch and microcontroller, the capacitor being configured to discharge when no power is being provided to the microcontroller and the tamper switch moves from the first position to the second position.

11. The tamper-detection device of claim 10, wherein the capacitor discharges and changes the input provided to the microcontroller such that when power is later provided to the microcontroller, the microcontroller is capable of determining that the tamper switch was in the second position while no power was provided to the microcontroller.

12. The tamper-detection device of claim 11, wherein the microcontroller is configured to disable a functionality of a device associated with the tamper-detection device, upon determining that the tamper switch was in the second position.

13. The tamper-detection device of claim 11, wherein the microcontroller is configured to generate and issue a message upon determining that the tamper switch was in the second position.

14. The tamper-detection device of claim 10, wherein the capacitor is further configured to maintain the input value provided to the microcontroller when no power is being provided to the microcontroller as long as the tamper switch stays in the first position.

15. The tamper-detection device of claim 10, wherein the capacitor is connected in parallel between the tamper switch and microcontroller.

16. The tamper-detection device of claim 10, further comprising a second switch connected between the tamper switch and the microcontroller, wherein the second switch is configured to set a logical value at the microcontroller representing whether or not the tamper switch is installed.

17. A safe equipped with the tamper-detection device of claim 10.

18. A lock equipped with the tamper-detection device of claim 10.

19. A method, comprising:

providing a device with a tamper sensor electrically connected with a microcontroller;

detecting that the tamper sensor has changed from a first state to a second state, wherein the detecting step occurs when the microcontroller is without power;

sending a signal to the microcontroller reporting the tamper sensor is in the second state, wherein the sending step occurs when the microcontroller is inoperable; and

registering, with the microcontroller, the signal reporting the tamper sensor is in the second state, wherein the registering step occurs after the microcontroller becomes powered.

20. The method of claim 19, further comprising determining with the microcontroller that the device includes a tamper sensor.

21. The method of claim 19, further comprising:

providing a signal generating device/circuit having time limited self-powering capability to generate and send a signal to the microcontroller reporting the tamper sensor has changes states when the microcontroller is without power.

22. The method of claim 21, wherein the signal generating device/circuit is a capacitor in series with a diode.