Power window circuit board overcurrent protection

• US 5,612,847 A
• Filed: 04/28/1995
• Issued: 03/18/1997
• Est. Priority Date: 04/28/1995
• Status: Expired due to Term

• Current Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Titus, Derrick, Kaufman, Dennis D., Malecke, Joseph F.
• Primary Examiner(s): Gaffin, Jeffrey A.
• Assistant Examiner(s): Medley, Sally C.
• Application Number:
  US08/430,562
• Time in Patent Office: 690 Days
• Field of Search: 361/58, 361/23, 361/24, 361/25, 361/27, 361/103, 361/106, 307/29, 307/31, 307/35, 307/12, 307/10.1, 318/101, 318/103, 318/434, 49/26, 49/28, 49/31, 49/118, 160/291, 160/291.3
• US Class Current: 361/58
• CPC Class Codes: B60R 16/037 for occupant comfort , e.g. for automatic adjustment of appliances according to personal settings, e.g. seats, mirrors, steering wheel

Abstract

A vehicle door (22) has a window (24) capable of being opened and closed. A master power window switch assembly (26) is mountable in an arm rest (28) of the door (22) near a driver of the vehicle. A polyswitch resettable fuse (56) is connected to a printed circuit board (50) of a master power window switch assembly (26) through a jumper terminal (58). An electrically conductive trace (52) is electrically connected to the jumper terminal (58). The polyswitch resettable fuse (56) may be used to limit current in the conductive trace (52) on the circuit board (50). Locating the polyswitch resettable fuse (56) between the power source (40) and the circuit board (50) permits design of the conductive traces (52), (53) and the circuit board electrical components for normal operating currents instead of significantly larger foreseeable motor stall current levels.

Claims

1. An apparatus comprising:

a plurality of automobile window motors, each one of said motors drawing a first, lesser amount of electric current when in a normal operating condition and drawing a second, substantially greater amount of electric current when in a stall condition;

a printed circuit board;

a plurality of automobile window switches mounted on said printed circuit board, each one of said switches being electrically connected with a respective one of said motors for controlling said one motor;

a source of electric power electrically connected with said circuit board;

at least one conductive trace on said circuit board for carrying current from said electric power source to all of said plurality of switches, said at least one conductive trace having a first current-carrying capacity; and

a polyswitch resettable fuse on said circuit board, said polyswitch resettable fuse being electrically connected in series between said electric power source and said at least one conductive trace;

said polyswitch resettable fuse having a first condition enabling substantially unimpeded current flow through said fuse when said polyswitch resettable fuse has a temperature less than a predetermined temperature;

said polyswitch resettable fuse being in the first condition when the amount of current passing through said polyswitch resettable fuse does not exceed said first current-carrying capacity of said at least one conductive trace;

said polyswitch resettable fuse having a second condition substantially blocking current flow through said polyswitch resettable fuse when said polyswitch resettable fuse has a temperature greater than said predetermined temperature;

said polyswitch resettable fuse changing from the first condition to the second condition when the amount of current flowing through said polyswitch resettable fuse exceeds said first current-carrying capacity of said at least one conductive trace.

2. An apparatus as set forth in claim 1 wherein said first current-carrying capacity of said at least one conductive trace is (a) greater than the sum of the currents drawn by all of said plurality of motors when all of said plurality of motors are in a normal operating condition, and is (b) greater than the amount of current drawn by any single one of said plurality of motors when said any single one motor is in a stall condition, and is (c) less than the sum of the currents drawn by any two of said plurality of motors when both of said any two motors are in a stall condition.