What Is a Current Sensor Circuit?

Efficiency has risen to become top priority in electrical systems in response to the demand for lower carbon dioxide emissions. Whether including more smart devices in electrical supply grids or the electrification of our automobiles, this global trend is driving the need for more efficiency in our electrical circuits. One major tool for achieving greater efficiency has been implementing more current sensing circuits which is a circuit that can measure current flowing through it. They are often used in battery systems to detect current while also monitoring for overcurrent situations, a short circuit, and the battery system’s state of charge. In addition, they keep systems safe and can protect from dangerous conditions like fires. In this article, we discuss two major methods of current sensing along with some general information about current sensing circuit uses.

Two Types of Current Sensing Circuits

Though several different variations exist, there are generally two major methods for implementing a current sensor circuit. These two methods are to either use a current sensor resistor or a Hall Effect sensor.

Using a Current Sensor Resistor

The first way to create a current sensor circuit is by implementing a current sensor resistor, also called a shunt resistor or resistive shunt. This type of resistor has a small value (a few milliohms), is very precise, and has a high power rating. Using Ohm’s law, it works by converting current into voltage. This is because the voltage drop across the resistor is proportional to the current that passes through it, and measuring the drop provides an estimate of the load current. This method is commonly used in low power systems that use less than 100A, such as doorbells and thermostats, as it is low-cost and very easy to implement with enough capacity to handle low power current.

Using a Hall Effect Sensor

The second way to build a current sensor circuit is by utilizing a Hall Effect sensor. Hall Effect sensors measure the way a magnet affects a circuit to determine its voltage. The sensor relies on the way that electrons are subjected to a magnet, causing electrons to be pushed or pulled to one side of a track without breaking the flow of current. By measuring the difference in charge between the two sides of an electrical track, the Hall Effect sensor can determine the voltage of the current without needing to create a break in the system to install a meter. For their greater capacity, Hall Effect sensors are often used in high power systems that use 100A or more, such as electric vehicles. Consequently, Hall Effect sensors are also more costly and complex to implement. However, their advantages are that they can work with high current and provide electrical isolation in devices that have multiple power sources.


Though their capabilities vary, both of these current sensing methods can be used to greatly increase the overall safety and efficiency of an electrical system. If you are in need of a dependable source for high-quality parts for your operations, including current sensor parts and resistor parts, Paragon Purchasing Services is ready to assist you with all that you require. As a premier supplier of aviation, NSN, and electronic equipment, we strive to make the procurement process as simple and convenient as possible for our customers. Browse our online catalog of available parts at your leisure or send an Instant RFQ form to receive a quote for your comparison in just 15 minutes or less upon our receipt of a completed form. With a widespread supply network, we guarantee expedited shipping on all orders, wherever you are located. Start the purchasing process with us today to see how easily we can fulfill each of your operational requirements.


November 20, 2023

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