Wiper circuit system for motor vehicles
First Claim
1. A wiper circuit system for driving a windshield wiper of an automotive vehicle having a vehicle battery, said system comprising, in combinationan electric motor adapted to be mechanically coupled to a windshield wiper and being controlled by an operating switch for different modes of operation;
- an oscillator circuit having an input coupled to said operating switch and having an output for applying variable frequency operating potential control signals to said motor;
means responsive to the voltage of said vehicle battery for varying the frequency of said oscillator circuit as a function of the vehicle battery voltage when said operating switch selects a continuous operation mode of operation of said motor; and
means for maintaining the frequency of said oscillator circuit to a constant value when said operating switch selects an intermittent operation mode of operation of said motor.
0 Assignments
0 Petitions
Accused Products
Abstract
A wiper system for motor vehicles. The wiper system has a switching circuit which derives from a timing signal, time-dependent switching and controlling signals provided by an oscillator that determines for example the duration of the intervals in an intermittent mode of operation or the reference time span for implementing anti-blocking protection of the wiper motor. The timing frequency of this oscillator is kept constant during the intervals in the intermittent mode of operation, otherwise it varies depending on the battery voltage when the wiper motor is operating. The intervals are thus maintained with precision, whereas the reference time span is adapted to the wiping time that changes as a function of the battery voltage when the motor is operating, thus ensuring optimal anti-blocking protection.
45 Citations
4 Claims
-
1. A wiper circuit system for driving a windshield wiper of an automotive vehicle having a vehicle battery, said system comprising, in combination
an electric motor adapted to be mechanically coupled to a windshield wiper and being controlled by an operating switch for different modes of operation; -
an oscillator circuit having an input coupled to said operating switch and having an output for applying variable frequency operating potential control signals to said motor; means responsive to the voltage of said vehicle battery for varying the frequency of said oscillator circuit as a function of the vehicle battery voltage when said operating switch selects a continuous operation mode of operation of said motor; and means for maintaining the frequency of said oscillator circuit to a constant value when said operating switch selects an intermittent operation mode of operation of said motor. - View Dependent Claims (2, 3, 4)
-
Specification