Electrical Geeks

As the name suggests “Automatic Night Lamp with Morning Alarm” was developed using Microprocessor. 8085 is the Heart of the system. The sensors are made with help of LDR which are Light Dependent Resistors, whose Resistance is inversely proportional to the Light falling on it. The LDR converts the light energy into electrical energy and this variable electrical energy was converted into digital signal (0 or 1) by using the timer IC555. The Timer IC output goes low when light falls on the LDR and the timer IC output goes high when the LDR was placed in dark circuit is as shown in below figure: circuit the flow chart for Automatic Night Lamp with Morning Alarm using 8085 Microprocessor is as shown in following fig. flow chart the program for Automatic Night Lamp with Morning Alarm using 8085 Microprocessor this is as shown below make sure that the Power supply pins & Port number before you connect the Hardware to the Trainer Kit. 0001   0000 0002   0000            

Introduction: In HT electrical distribution, the system can be earthed or unearthed. The selection of earthed/unearthed cable will depend on system. If distribution system is earthed then we have to use cable which is manufactured for earthed system. (Which the manufacturer specifies). If the system is unearthed then we need to use cable which is manufactured for unearthed system. The unearthed system requires high insulation level compared to earthed System. For earthed and unearthed XLPE cables, the IS 7098 part2 1985 does not give any difference in specification. The insulation level for cable for unearthed system has to be more. Earthed System:            Earlier the generators and transformers were of small capacities and hence the fault current was less. The star point was solidly grounded. This is called earthed system. In Three phases earthed system, phase to earth voltage is 1.732 times less than phase to phase voltage. Therefore voltage stress on cable

 here, u can get electrical engineering question and answers and multiple choice questions and interview questions part - 1 1)     Why ELCB cannot work if Neutral input of ELCB does not connect to ground? ELCB is used to detect earth leakage fault. Once the phase and neutral are connected in an ELCB, the current will flow through phase and that same current will have to return neutral so resultant current is zero. Once there is a ground fault in the load side, current from phase will directly pass through earth and it will not return through neutral through ELCB. That means once side current is going and not returning and hence because of this difference in current ELCB will trip and it will safe guard the other circuits from faulty loads. If the neutral is not grounded fault current will definitely high and that full fault current will come back through ELCB, and there will be no difference in current. 2)     What is the difference between MCB & MCCB, Where i