The circuit presented here operates a relay for Fixed Timer Interval. So the device or machine connected with relay operates for same time. The device once switched ON, automatically switches OFF after Fixed (set) Time Interval when relay switches OFF. The Time Interval can be varied and it is displayed on 7 Segment Display. This kind of circuits can be used in many applications where it is required to operate any device or machine for Fixed Time Interval.

Object counters are widely used devices. They are used at different places for different purposes and different usages. They can be used as visitor counter, vehicle counter material/product counter etc. Some of the examples where object counters can be used are: It can be used in LIFT to count and display number of persons inside the lift at a particular given time. The Object Counter can also be put to use in any big super market or shopping malls as a visitor counter, to keep track of the number of visitors who have visited the Mall, on the conveyor belt in the industry to count number of objects passed and in parking lots to count and display number of vehicles inside the parking lot.Thus the application areas are varied where object counters are used. 

 Here is an Unusual LED indicator for the Battery. It turns on fully when the battery voltage is above 13 volts and starts to blink faintly when the voltage drops below 12 volts .Finally the LED turns off when the voltage drops below 10 volts. Its design is unusual because the LED driver transistor is…

The circuit presented here operates a relay for Fixed Timer Interval. So the device or machine connected with relay operates for same time. The device once switched ON, automatically switches OFF after Fixed (set) Time Interval when relay switches OFF. The Time Interval can be varied and it is displayed on 7 Segment Display. This kind of circuits can be used in many applications where it is required to operate any device or machine for Fixed Time Interval. Like·         The Alarm Signal (or Bell) once triggered, remains ON for Fixed Time Interval and then shuts off automatically·         In Manufacturing Industries the Motors have to be rotated for Fixed Time Interval once start button is pressed. It stops automatically when time period is overTime operated relay circuit is build using IC555. To display the time period in seconds 2-digit decade counter is build using CD4026 chip. Another IC555 is used to provide 1 Hz pulse to update time period after every 1 sec.