07-11-2017, 11:22 AM
An "Overcurrent Relay" is a type of protection relay that operates when the load current exceeds a pre-set value. In a typical application, the overcurrent relay is used for overcurrent protection, connected to a current transformer and calibrated to operate at or above a specific current level. The relay is implemented by a combination of a look-up table and a counter that is fed as part of the assembly language program in the 8051 microcontroller kit. Software development and testing is done using a microcomputer module based on the microcontroller 8051. a certain current value is fed to the hardware consisting of precision rectifier, filters, sampling and retention circuit, adc (ic integrated into the 8051 microcontroller kit) and, finally, digitally converted retention values of the current they are delivered to the microcontroller. an appropriate program in assembly language 8051 was introduced in the kit that detects and judges the digital value of the current and provides the trigger signal in the form of led when the digital value of the given current is greater than a particular threshold value.
