Windshield wiper control with stall protection
First Claim
1. A windshield wiper control comprising:
- a wiper motor for driving a windshield wiper through a wipe cycle in which the wiper moves from a first position to a second position and back to said first position;
a sensor communicating with the motor providing a wiper motion signal indicating a position of the motor;
a wiper switch;
a microcontroller electrically connected to receive signals from the sensor and switch and to switchably supply electrical power to the motor, the microcontroller operating according to a stored program to;
(a) respond to switch on signal from the switch by periodically supplying electrical power to the motor for single wipe cycle at a period substantially equal in time to the time between the occurrence of the switch on signal and a previous wipe cycle regardless of an intervening switch off signal; and
(b) respond to the switch off signal from the switch by removing electrical power to the motor at the completion of a wipe cycle;
whereby the period between wiper cycles may be lengthened to a desired period by providing a switch off signal at a time when a periodic wipe cycle would have occurred and then providing a switch on signal at the desired period after the previous wiper cycle.
1 Assignment
0 Petitions
Accused Products
Abstract
A windshield wiper control detects a stall condition of the windshield wiper motor such as may be caused by a freezing of wiper blades to the windshield by monitoring the commutating switch normally used to park the windshield wiper blades when the wipers are turned off. Failure of the signal from the switch to change indicates the motor has stalled and causes a timer holding a value greater than a wiper cycle to time out and de-energize the wiper motor. The wiper motor is re-energized by turning off then on again the wiper control. A method of setting the interval between intermittent operation of the wiper with a single switch, times from previous wiper cycles to the switch activation to set a longer or shorter wiper cycle interval.
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Citations
15 Claims
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1. A windshield wiper control comprising:
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a wiper motor for driving a windshield wiper through a wipe cycle in which the wiper moves from a first position to a second position and back to said first position; a sensor communicating with the motor providing a wiper motion signal indicating a position of the motor; a wiper switch; a microcontroller electrically connected to receive signals from the sensor and switch and to switchably supply electrical power to the motor, the microcontroller operating according to a stored program to; (a) respond to switch on signal from the switch by periodically supplying electrical power to the motor for single wipe cycle at a period substantially equal in time to the time between the occurrence of the switch on signal and a previous wipe cycle regardless of an intervening switch off signal; and (b) respond to the switch off signal from the switch by removing electrical power to the motor at the completion of a wipe cycle; whereby the period between wiper cycles may be lengthened to a desired period by providing a switch off signal at a time when a periodic wipe cycle would have occurred and then providing a switch on signal at the desired period after the previous wiper cycle. - View Dependent Claims (2, 3, 4, 5)
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6. A windshield wiper control for use with a windshield wiper system of a vehicle having a wiper motor controlled by a motor switch for driving a windshield wiper through a wipe cycle in which the windshield wiper moves from a first position to a second position and back to said first position, a sensor communicating with the motor providing a wiper motion signal indicating motion of the motor, and a wiper switch providing a wiper-on signal, the control comprising:
an electronic circuit connected to the motor, sensor, and wiper switch to receive the motion and wiper-on signals, and for operating the motor switch to control a supply of electrical power to the motor, the electronic circuit including; (a) a first logic element which following the wiper-on signal by activating the motor switch to supply electrical power to the motor; and (b) a second logic element, which in response to the first logic element supplying electrical power to the motor, deactivates the motor switch to remove electrical power to the motor in a first instance when the wiper-on signal is no longer present and in a second instance when the wiper-on signal is present and the wiper motion signal is no longer present. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15)
Specification