Signal isolator is often used in industrial automatic control system, the key function is to convert and output the input data signal. In order to master the signal isolator in all directions, it is not enough to only understand the advantages of the signal isolator, we also solve the product type of the signal isolator to do a simple master. In particular, it is more common that according to the different power supply methods, the signal isolator can be divided into three types: loop power supply type, independent power supply type and input power supply type. The following is a simple and detailed introduction to these three signal isolators.

The loop-powered I/O is a two-wire, which is more suitable for use in the field of binary intelligent transmitters. However, this kind of signal isolator has a defect because the isolator is equivalent to a load on the power supply circuit, so it has certain provisions on the working voltage on both sides of the power supply circuit, and the working voltage on both sides of the general protection cannot exceed 6 volts. Because of this limitation, it will cause it to reduce the working standard voltage of the binary intelligent transmitter distribution equipment by a lot.

The independent power supply type is the most widely used isolator in manufacturing, mainly because it has the advantages of high transmission accuracy, easy wiring and complete protection of switching power supply, input and output. However, pay attention to the independent power supply of such isolators when applying them.

Output loop power supply is now more and more widely used in industrial video surveillance systems. The role of this type of isolator is relatively, it moderates the advantages of the above two isolators, and bypasses their defects in the design scheme. The advantages above the two are much stronger.