Windshield wiper control having a sensor and a repeatedly renewed offset signal

• US 4,495,452 A
• Filed: 08/08/1983
• Issued: 01/22/1985
• Est. Priority Date: 12/08/1981
• Status: Expired due to Term

• Current Assignee: Leopold Kostal GmbH & Company KG
• Original Assignee: Allan Boegh-Peterson
• Inventors: Boegh-Peterson, Allan
• Primary Examiner(s): Witkowski, Stanley J.
• Assistant Examiner(s): Ro, Bentsu
• Application Number:
  US06/525,035
• Time in Patent Office: 533 Days
• Field of Search: 318/443, 318/444, 318/DIG. 2, 318/483, 318/643, 15/250 C, 15/250.13, 200/61.05
• US Class Current: 318/444
• CPC Class Codes: B60S 1/0818 including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
• CPC Class Codes: B60S 1/0825 Capacitive rain sensor
• CPC Class Codes: Y10S 15/15 Moisture responsive
• CPC Class Codes: Y10S 318/02 Windshield wiper controls

Abstract

A windshield wiper control, e.g. for use in automobiles, receives information as to the amount of humidity on the windshield from a sensor (1) which is arranged within the area which is swept by the windshield wipers, and adjust the wiper frequency in relation thereto. The windshield wiper control includes a circuit (2) which remembers the signal from the sensor just after the windshield wiper has passed the sensor. The signal is compared to the signal directly from the sensor by a comparator (3). Having detected a certain change, the amplifier (4) is activated which turns on the wiper motor through a relay (5). The sensor may be of the capacitive type.

Claims

1. A windshield wiper control systems for automatic operation based upon the presence on a windshield of a predetermined amount of moisture, including a wiper, a motor for driving the wiper, a moisture sensor arranged within the area swept by the wiper, a reference store connected to the output of the sensor, a reference signal stored in said store, and means to compare the sensor output signal to said reference signal so that the motor is activated when the moisture amount exceeds the amount of the reference signal, so that each time the wiper has just passed the sensor, the sensor output signal is written to the store and is retained as a reference at the next comparison, and circuit means allowing said reference signal to continuously follow slow changes of the signal from the sensor.