What are Hall Effect Sensors and Current Sense Resistors?
Hall effect sensors and current sense resistors are two types of sensors used to measure current in electronic circuits. The Hall effect principle is employed by hall effect sensors to measure the magnetic field generated by current passing through a conductor, while current sense resistors determine the voltage drop across a resistor that is positioned in series with the current-carrying conductor.
Hall sensors are commonly used in automotive and industrial applications, as well as in electric motors and generators. They are used to measure current, RPM, and position, as well as for speed control and anti-lock brake systems in vehicles. Hall sensors are critical in electric motors and generators because they determine the position and speed of the rotor, which is necessary for correct operation.
LEM current sensors and SEM sensors are two well-known brands of hall effect current sensors. LEM current sensors are renowned for their accuracy and reliability, as well as their ability to handle high currents and high temperatures. In contrast, SEM sensors are recognized for their compact size and simplicity of use, as well as their affordability.
Along with hall effect sensors, current sense resistors are also a prevalent method of measuring current in electronic circuits. A current sense resistor is a resistor that is placed in series with the current-carrying conductor, and the voltage drop across the resistor is proportional to the current flowing through it. The resistor value is selected to ensure that the voltage drop across it is minimal enough not to significantly impact the circuit’s operation but substantial enough to be precisely measured.
Current sense resistors are frequently used in power management applications, such as in battery chargers and power supplies. They are also used in motor control circuits to measure the current flowing through the motor windings, and in electronic circuit breakers to detect overcurrent conditions. Metal film, metal oxide, and shunt resistors are some common types of current sense resistors. Metal film resistors are usually more accurate than metal oxide resistors, but they are also more costly. Shunt resistors are specifically designed for current sensing applications and are very low resistance, often only a few milliohms.
When selecting a hall effect sensor or a current sense resistor for a particular application, several factors should be considered, including the maximum current that will be measured, the accuracy required, the temperature range, and the cost.
In summary, Hall effect sensors are a critical component in current sensing technology, and they have several advantages over other current sensing technologies. These sensors are non-intrusive, accurate, reliable, and can measure both AC and DC current, making them suitable for a wide range of applications. Popular Hall effect current sensor brands, such as LEM and SEM Sensor, offer a range of current sensing solutions that cater to different applications and industries.