The motor typically used in a car’s windshield wiper system is a DC (Direct Current) motor. Specifically, it is usually a small, permanent magnet, brushed DC motor. This type of motor is preferred because it provides the necessary torque to move the wiper arms and blades across the windshield at varying speeds, including the ability to reverse direction, which is needed for the wiper’s return stroke.

The wiper motor is connected to a linkage mechanism that converts the rotational motion of the motor into the back-and-forth motion of the wiper arms. The motor speed is often controlled by resistors or a pulse width modulation (PWM) control circuit to allow for different wiper speeds, such as intermittent, slow, and fast.

Car wiper blades work through a combination of mechanical, electrical, and control systems that enable them to clear water, dirt, and debris from the windshield. Here’s a breakdown of how wiper blades work:

1. Wiper Motor

At the core of the system is a DC motor that powers the movement of the wiper blades. The motor is connected to a linkage system (also called a transmission) that converts the motor’s rotational motion into the back-and-forth motion needed to sweep the windshield.

2. Linkage Mechanism

The wiper motor is connected to a series of linkages and arms that transfer the motor’s rotation into a back-and-forth sweeping motion. The linkages ensure the wiper blades move in a synchronized motion across the windshield, typically following an arc pattern.

3. Wiper Blades

The wiper blades are attached to the ends of the wiper arms. These blades are made of flexible rubber (or synthetic material) that is designed to press firmly against the windshield. The wiper blade is responsible for making direct contact with the glass and scraping away water, dirt, and other debris.

4. Control Mechanism

The driver controls the wipers using a stalk (lever) on the steering column. Modern wiper systems have several settings, including:

• Off: No movement.
• Intermittent: Wipers move at intervals, useful for light rain.
• Low speed: Continuous, slow wiping.
• High speed: Continuous, fast wiping.

The wiper control system may include a pulse width modulation (PWM) control to vary the speed of the motor based on the selected setting.

5. Intermittent Wipers

Many cars have an intermittent mode, where the wipers sweep at intervals instead of continuously. This is controlled by a relay or electronic control module, which turns the wiper motor on and off at set intervals. The delay can often be adjusted by the driver.

6. Park Position

When the wipers are turned off, they don’t stop randomly on the windshield. A parking mechanism brings the wipers back to their resting position, usually at the bottom of the windshield, ensuring they’re out of the driver’s field of view.

7. Washer System

The wiper system often works in conjunction with a washer system that sprays water or washer fluid onto the windshield. The washer fluid is stored in a tank and is pumped through nozzles onto the windshield when activated by the driver.

8. Rain-Sensing Wipers (Optional)

In modern cars, some wipers come with rain sensors that automatically detect moisture on the windshield and activate the wipers. The sensor sends signals to the wiper control system to adjust the speed based on the intensity of the rain.

Summary of the Working Process:

• When the driver activates the wipers, the DC motor turns on.
• The motor moves a set of linkages that translate the rotational motion into the sweeping arc.
• The wiper blades, attached to arms, move back and forth across the windshield, clearing water and debris.
• Depending on the setting, the speed and frequency of the wiper movement vary, ensuring clear visibility for the driver.

This system ensures a clean and clear windshield, especially in adverse weather condition.

The control of car wipers is managed by several components working together, allowing the driver to operate the wipers in various modes. Here’s how the control system works:

1. Wiper Control Stalk (Switch)

• The wiper control stalk or lever is usually located on the steering column. It allows the driver to select different wiper settings, such as:
  • Off: No wiper activity.
  • Intermittent: Wipers move at set intervals (timed delays).
  • Low Speed: Continuous, slow wiping.
  • High Speed: Continuous, fast wiping.
  • Washer/Wiper: Activates the washer fluid spray along with wiper movement.

  This stalk may also have controls for adjusting the delay in the intermittent mode.

2. Wiper Relay or Control Module

• The wiper relay or electronic control module receives signals from the wiper stalk and controls the power sent to the wiper motor. It can switch the motor on and off, control the speed, and manage the timing for intermittent wiping.
• In cars with more advanced systems, the control module might also handle inputs from other sensors, like rain sensors, to automatically adjust wiper speed based on the amount of moisture detected.

3. Wiper Motor

• The DC motor that drives the wipers is controlled by the relay or control module. Depending on the signal received, the motor operates at different speeds (slow or fast) or in intervals (for intermittent wiping).

4. Intermittent Wiper Control

• The intermittent wiper control function is usually managed by a timer circuit within the control module. The timer determines how long the wipers pause between each swipe in intermittent mode. This delay can often be adjusted by the driver using a dial on the wiper stalk.

5. Rain Sensor (Optional)

• In vehicles equipped with rain-sensing wipers, a rain sensor on the windshield detects the amount of rain or moisture and sends this information to the control module. The module then adjusts the wiper speed or activates the wipers automatically without driver input, based on the detected conditions.

6. Parking Mechanism

• The wipers have a parking mechanism that ensures they return to a specific resting position when turned off. This is controlled by the motor and linkages, often with a dedicated switch or cam that tells the motor to stop when the wipers reach the bottom of the windshield.

7. Manual Override

• Some systems may allow the driver to manually override the automatic functions (like rain-sensing) to take full control of the wiper settings.

Summary:

The wiper system is controlled primarily by the wiper control stalk, which sends signals to a relay or control module. This module manages the power to the wiper motor, controlling the speed and timing based on the driver’s input or, in some cases, inputs from additional sensors like a rain sensor. The system also includes mechanisms for parking the wipers when not in use.