Signal Isolator Working and Its Applications

The signal reliability can be achieved by two essential parameters like high-quality equipment as well as a good measurement. Sometimes, if the installation of equipment cannot be done properly then the signal can have the inferior quality. To overcome this problem, signal isolators or conditioners are used to protect the equipment. These isolators are an excellent blend of frequency response, signal handling, and accuracy. Some of the isolators are suitable with two-way field communication which can be achieved by the superimposition of digital communication. This article discusses an overview of the signal isolator.

What is a Signal Isolator?

The signal isolator definition is an electrical device which is used to remove earth loop errors which are caused by noise & signal interference problems. These isolators use several electronic methods for interrupting the two grounds connections while passing an exact signal with accuracy or with a small loss.

Signal isolator gives electrical isolation among the input & output circuits. The signal can be connected through a transformer to the output. These isolators also break the straight electrical path among loop ends. They guard against hazardous calculated variable voltages & enhance protection from spikes and surges.

Working Principle of Signal Isolator

The working principle of a signal isolator is similar to signal interfaces & signal converters. These isolators are frequently used to split, share, step-down, protect, linearize, boost, & process signals digitization. The main function of this is to split the electric (galvanic) lane among circuits from grounded to dissimilar potentials. An electrical lane can be defined as a lane where there is a straight electrical link among electrical circuits which allows the flow of current.


The working of signal isolator can be done using the following two methods namely analog and discrete. Analog signal isolation includes an isolation transformer for chopping, isolating, and recreating the signal. Whereas discrete signal generation is used to chop, optically transmit, and recreating the signal. When the signal isolator used this discrete technique is named as optoisolators. The selection of these two methods can be done based on the circuit requirement.

Types of Signals Isolators

Signal isolators are classified into different types which include the following.


1). Resistance Input Isolators

These types of isolators are used as slidewire, strain, RTD, & potentiometer transmitters.

2). Millivolt Isolators

These types of isolators are used as millivolt transmitters and thermocouple.

3). Current or Voltage Isolators

These types of isolators are used as deviation alarm notification, alarm tripping, & other particular application transmitters.


The applications of signal isolator include the following.

  • Signal change & process value scaling.
  • Filtration of noise
  • Protect against EMC
  • Crosstalk elimination
  • Electrostatic filtration
  • Ground loops elimination

Thus, this is all about signal isolator. From the above information finally, we can conclude that these are applicable for medical, industrial and where electrical isolation can be necessary for security, and also used to amplify signals, to step down hazardous, high-voltage signals toward safety levels. Some of the industries are providing signal isolators with integral safety features for utilizing in a variety of environments Here is a question for you, what are the required components to build a signal isolator circuit?