Patent ID: 8887440
Filing Date: 2014-11-18
Classification: E05F,E05Y

Abstract:
1. An alarm system configured for controlling a garage door comprising: a first antenna configured to be mounted to a left end of the garage door; a second antenna configured to be mounted to a right end of the garage door; a signal generator logic configured to generate a periodic signal based on a first capacitive value of the first antenna and a second capacitive value of the second antenna, wherein the signal generator logic comprises a first invertor, a second invertor, and a third invertor, and wherein the first antenna is connected between the first invertor and the third invertor, wherein the second antenna is connected between the second invertor and the third invertor, wherein the first invertor, the second invertor, the third invertor, the first antenna and the second antenna form a ring that generates the periodic signal, and wherein the signal generator logic provides transmit power to the first antenna and the second antenna; detection logic configured to detect a change in a characteristic of the periodic signal caused by movement of an object near the garage door wherein the detection logic is configured to detect the change by comparing a first value based, at least in part, on the first capacitive value of the first antenna and a second value based, at least in part, on the second capacitive value of the second antenna; amplification logic configured to amplify the change; alarm detection logic configured to determine if the change is an alarm condition; and alarm response logic configured to stop a movement of the garage door when the change is an alarm condition.