Efficiency Detector for Relay & Circuit Breaker
The Important Specification of Relays and Circuit breakers is the ON time (the time taken by device to close the contacts, when the coil is energized) & OFF time (the time taken by the device to open the contacts, when the coil is de-energized). The circuit breakers are used in electrical wiring to switch off the mains supply, when any load draws more current or circuit gets short. The circuit breakers should operate quickly to avoid heavy losses in the industries. Most of the equipments like UPS need the faster relay (Relays with less ON time & OFF time) to change the load power from mains supply to battery. But we don’t have any standard equipments to measure the relays / circuit breakers ON/OFF time, which is usually in msec. In this project we are developing an equipment to measure the Relays / Circuit breakers ON/OFF time. The equipment is based on Atmel Microcontroller AT89C51. The basic block diagram is shown below. The controller takes the user entries from the keypad. The test results will be displayed in the alphanumeric LCD display. The basic firmware for the microcontroller is written in ‘C’ language and cross complied using C cross complier. The cross compiler generates the machine code for the microcontroller and the machine code is stored/programmed in flash memory of micro controller. The microcontroller has internal timer, which is used to measure the ON/OFF time of the relay accurately. The controller applies power to the relay & starts the timer. When the relay / circuit breaker closes the contacts, it is sensed by the controller thru I/O port lines and Stops the timer. The time period is then displayed in the LCD. When the user press the next key the controller releases the supply of the coil and restarts the timer. When the contacts get open, the timer stops and the time period is displayed in LCD.