Apparatus and method for detecting theft of electronic equipment

• US 5,231,375 A
• Filed: 06/07/1991
• Issued: 07/27/1993
• Est. Priority Date: 06/07/1991
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: ROLM Co. (Siemens AG)
• Inventors: Edwards, Bruce H., Goffinet, Kevin P., Torrey, Wayne D., Sanders, Kirk D., Rasko, George A.
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US07/712,027
• Time in Patent Office: 781 Days
• Field of Search: 340/568, 340/571, 340/664, 340/663, 340/687, 340/529-530, 340/652, 340/693, 307/131, 439/489, 439/917
• US Class Current: 340/568.2
• CPC Class Codes: G08B 13/1409 for removal detection of electrical appliances by detecting their physical disconnection from an electrical system, e.g. using a switch incorporated in the plug connector

Abstract

A system is disclosed for deterring theft of portable electronic equipment that operates in accordance with an industry standard known as EIA-232-D. A theft deterrent unit monitors signal current transmitted between interconnected electronic units. When one or more of the interconnected electronic units is disconnected, the theft deterrent unit detects the cessation of signal current and activates an alarm. The alarm may be used to generate a local alarm such as, for example, an audible alarm, and the alarm signal may be transmitted to a central alarm system for further processing.

Claims