Introduction
Integrated circuits (ICs) are responsible for powering many devices we use on a daily basis. They function by manipulating and controlling electrical signals through the use of various sensors. One important area of sensors used in ICs is the detection of the presence or absence of a magnetic field.
In this blog post, we will compare the two most common types of IC magnetic field sensors: reed switches and Hall effect sensors. While both of these sensors detect magnetic fields, they differ in their construction, sensitivity, and applications.
Reed Switches
A reed switch is a sensor that consists of two ferromagnetic blades that move when a magnetic field is present. The switch is normally open and closes when the magnetic field is present. Reed switches are commonly used in applications where they are activated by a magnetic field, such as magnetic door switches and water level sensors.
One of the best features of reed switches is their simplicity. They are easy to use and require no power supply. Additionally, they are relatively cheap and small in size. However, they have some limitations. Because the sensitivity of a reed switch decreases with increasing temperature, they are not suitable for high-temperature applications. Their mechanical structure also makes them prone to mechanical failures, which can affect their operation.
Hall Effect Sensors
Hall effect sensors measure the strength of a magnetic field perpendicular to the sensor's surface. In contrast to reed switches, Hall effect sensors require power to operate, but they provide accurate and consistent results. They can measure both AC and DC magnetic fields and are less sensitive to temperature fluctuations when compared with reed switches.
Hall effect sensors are widely used in applications such as speed detection, current sensing, and position sensing. They are commonly known for their ability to measure the direction of the magnetic field as well as its strength.
Comparison
To summarize, reed switches are inexpensive and easy to use, but they are not suitable for high-temperature applications and have limited accuracy. Hall effect sensors, on the other hand, are more accurate and reliable but require a power source to operate.
When considering which sensor to use, the designer should consider the specific applications and requirements. In a situation where cost is the primary concern, a reed switch may be the ideal choice since they are cheaper. If high accuracy and reliability are required or the sensor needs to perform well at elevated temperatures, then the designer should consider using a Hall effect sensor.