Wire Current and Resistance

Like garden hoses, electrical wires are only designed to carry a limited amount of current to prevent short circuits. Unlike water and garden hoses, however, the current capacity of a wire is not directly proportional to the gauge.

A six-gauge wire (American Wire Gauge standards), for instance, has a 4.11mm diameter and a current capacity of 37 amps for power transmission, while a twelve-gauge wire only has a 2.05mm diameter and 9.3 amps—more than half the capacity. This isn't just because the wire is smaller; the electrical resistance grows as it shrinks.

The Process Behind Inductive Proximity Sensors

Position can be determined via one of two ways—either by determining ‘distance’ (the length of separation between two points) or by ‘rotation’ (angular movement). Sensors that are positional in nature can detect the movement of an object using linear sensors that employ the distance method or through rotational sensors that compute for rotation.

One type of positional sensor is the “Linear Variable Differential Transformer (LDVT), an inductive-type sensor that functions similar to the AC transformer when it comes to measuring movement. A common type of inductive positional sensor is the Eddy current sensor, which is mainly used to detect objects in close proximity. Due to this characteristic, Eddy sensors earned the more popular moniker ‘proximity sensors’.

Analog vs. Digital Sensors

There are many different types of sensors and transducers, but in general, all of them can be classified into two basic types: analog and digital. So which one is more useful to your needs? Find out below.

Analog sensors

Analog sensors create continuous and generally proportional output signal to that of the quantity being measured. Physical quantities such as Strain, Temperature, Pressure, Displacement and Strain, among others, are all analog because of their continuous characteristic. Analog sensors share this continuous nature, producing signals that change smoothly over time.

Current Sensing in the Manufacturing Industry

Electric motors are used extensively in the manufacturing industry. Whether AC- or DC-powered, electric motors are used to drive conveyors, fans, pumps, and a broad range of specialized equipment designed to speed up and automate specific manufacturing tasks. Many types of motors exist for many different applications, but they all have one thing in common: They all require electrical current to generate the magnetic fields necessary for them to function.

The need to monitor electric current

When an electrical motor’s current is monitored, useful information can be obtained regarding the status of the motor and the equipment it runs. Consequently, this information can be used to protect both the motor and the equipment connected to it.

Typical Applications for DC Current Sensors

The ability to monitor currents discretely is often a requirement for the accurate control of the complex DC circuits used in many commercial and industrial applications today. DC current sensors are often used to facilitate the monitoring required. These are used in applications such as:

Arming Your Clients against Electric Shock

When you’re in the business of providing power monitoring equipment, you should always be ready to offer safety precautions to your customers. With the potentially fatal hazards associated with electrical systems, your customers should be fully aware of the risks and invest on ways to prevent them. By giving them useful information, you may even bring them to better appreciate the technologies you provide.

Understanding Current Sensing

Current sensing is used to measure the flow of electricity that passes through a point. Specifically, it measures how much current is flowing in a wire. Commonly used for circuit protection and controlling, it’s also intended for monitoring electricity and enhancing its performance.

What Does a DC Current Sensor Do?

DC current sensors, in simple terms, take electrical measurements in the same way a thermometer determines the temperature of an item or area. Like all other measuring devices, DC current sensors can function to make simple and complex measurements. In its most basic form, a current sensor detects electrical current in a wire and generates a signal proportional to it.

DC current sensor generated signals can be utilized to display the measured current in an ammeter or can be stored for further analysis in a database. Moreover, it can also be used for control purposes of electrical devices. As a measuring device, DC current sensors detects the current input and can come out with output signal for both unipolar and digital output types. For a unipolar output, it duplicates the wave shape of the sensed current. For a digital output, on the other hand, it changes when the sensed current exceeds a certain threshold.

DC current sensors, in some cases, can be connected directly to electrical instruments while it is more common that some signal conditioning is used. Some current-sense applications call for isolation between the DC current sense’s resistor and the measurement circuits. In such cases, isolation amplifiers and modulators may be used.

DC current measurement don’t just take place in laboratories anymore as many common devices like battery chargers have some form of current sense resistor in them. This is why knowing the basics of current sensors is important.

Considerations in Choosing a Current Sensor

Whether in homes or businesses, cost is often one of the primary considerations in procuring devices,  such as a current sensor. You can certainly find products that would fit your budget, but you have to be wary of the value you get. With careful consideration, you can avoid buying inappropriate or low quality current sensors that can only result in high repair costs or inefficient outcomes.

Know the purpose for a current sensor

Current sensors can measure various energies, such as light, temperature, and magnetic fields, and convert the parameters to measurable electrical signals. Mainly used in power or instrumentation systems, this device is essential to those who wish to monitor electrical and other energy levels present in a process or situation. In industries, current sensors are typically used in batteries and chargers, voltage regulators, power-generating equipment, and other machines or electronics.

A DC current sensor is used for batteries, fuel, and solar cells, which has currents that flow in a single direction (direct current). On the other hand, an AC current sensor is commonly used in power sources that create alternating currents, which supply electricity.

Study specifications

Once you know the specific type of current sensor to acquire, pay attention to the specifications of available products. Distributors will provide comprehensive details on a product’s features and functionality. Make sure that you choose a product that complies with standards on accuracy, and which provide detailed parameters for its effective use, such as measurements, ranges, calibrations, and others.

Choosing a Split-Core Transformer

Current measurement is vital to ensuring the proper delivery of electricity. That’s why you must choose the best current transformer on the market for the most accurate measurements possible.

These days, many companies choose to implement split-core transformers for retrofit measurements. Given their designs, they are extremely easy and safe to install, and do not require the power line to be disconnected prior to installation.

Of course, there are many types and models of split-core transformers out there. To make purchasing easier, keep these buying tips in mind:

Take Note of Capacity

When looking for split-core transformers, the first consideration should be its capacity. After all, you wouldn’t want to purchase a model that has a lower capacity rating than the power line it’s supposed to measure. Fortunately, some brands offer transformers that have a rated input of up to 200 Amp.

Accuracy

With the appropriate capacity rating defined, your next consideration should be the accuracy of the product. For split-core transformers, an accuracy of 10-130% of the rated current is ideal. Linearity accuracy should also be rated ±1%.

Your Supplier

Of course, choosing a top-notch supplier is just as important as choosing an excellent product. With their help, you’ll gain access to a wide variety of quality products at reasonable prices. They’ll also ensure that your orders are delivered on time and in excellent condition.