Overcurrent protection circuit and AI module provided with same

Abstract

The invention discloses an overcurrent protection circuit and an AI module provided with the same. The AI module comprises a power supply source for supplying power to onsite instruments, and multiple signal input channels, wherein each signal input channel is used for respectively transmitting signals acquired by each onsite instrument to a CPU module, a power supply loop for supplying power to each onsite instrument is provided with an overcurrent protection circuit, the input end of each overcurrent protection circuit is electrically connected with the power supply source, and the output end of each overcurrent protection circuit is used for electrical connection with each onsite instrument. By use of the overcurrent protection circuit provided by the invention, each signal input channel in the AI module can be effectively and safely protected, other channels are not affected if one signal input channel generates a fault, and after the fault is removed, the channel can be automatically recovered.

Description

technical field [0001] The invention relates to the field of DCS control systems, in particular to an overcurrent protection circuit and an AI module provided with the overcurrent protection circuit. Background technique [0002] In the DCS control system, many 4-20mA current input modules with power distribution will be used. When the field instrument fails, such as a short circuit, resulting in excessive current, or a load mismatch that causes the current to exceed the specified value, it will cause damage to the module channel and power supply. The existing method is not to directly deal with this channel, but to add a fuse to the power supply, see Figure 6 , the disadvantage is that only when the current is too large due to the short circuit of the load on site, the fuse at the power supply terminal will work, and at the same time, a channel failure will affect the work of other adjacent channels. Contents of the invention [0003] The purpose of the present inventio...

AI Technical Summary

Problems solved by technology

When the field instrument fails, such as a short circuit, resulting in excessive current, or a load mismatch that causes the current to exceed the specified value, it will cause damage to the module channel and power supply

The existing method is not to directly deal with this channel, but to add a fuse to the power supply, see Image 6 , the disadvantage is that the fuse at the power supply terminal only works when the current is too large due to a short-circuit of the load on site, and at the same time, a channel failure will affect the work of other adjacent channels

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