electrialstandards

This is simple distance meter with 6LEDs. you can replace the last red led with a buzzer. distance range: <5 to 30cm ultrasonic module: HC-SR04 NOTE: Ultrasonic module can detect distance range from 2cm to 450cm but in this project i set the distance range from <5 to 30cm. code: #define trigPin 7 #define echoPin 6 #define led 13 #define led2 12 #define led3 11 #define led4 10 #define led5 9 #define led6 8 int sound = 250; void setup() {   Serial.begin (9600);   pinMode(trigPin, OUTPUT);   pinMode(echoPin, INPUT);   pinMode(led, OUTPUT);   pinMode(led2, OUTPUT);   pinMode(led3, OUTPUT);   pinMode(led4, OUTPUT);   pinMode(led5, OUTPUT);   pinMode(led6, OUTPUT);   } void loop() {   long duration, distance;   digitalWrite(trigPin, LOW);   delayMicroseconds(2);   digitalWrite(trigPin, HIGH);   delayMicroseconds(10);   digitalWrite(trigPin, LOW);   duration = pulseIn(echoPin, HIGH);   distance = (duration/2) / 29.1;   if (distance <= 30) {     digitalWrite(led, HIGH);     sound = 25

As we have seen in open circuit test that it is done on low voltage winding. Short circuit test is done of High voltage winding. In this case Ammeter, Voltmeter, Wattmeter are connected on High voltage winding of the transformer. This test is done to calculate copper losses in Transformer at full load. This test is performed on HT side not on LT side as Short circuit test in Transformer is conducted at its rated current which can be easily obtained by applying 5-6% of normal voltage. If we conduct Short circuit test on LT side by short circuiting HT side then Voltage of HT winding falls to zero which leads to very high current on High voltage winding leading to burning out of winding. For no load test on Transformers visit link:- http://electrialstandards.blogspot.in/2015/09/no-load-test-on-transformers-open.html Now lets take a Example if we have Transformer 2 MVA, 415V/11000V then  if we perform Short circuit in LT side the current will be:- 2     X      10^6 =   2782A 1.732 X 415 N

Open Circuit Or No Load Test on Transformer Open circuit test is also known as no load test. This test is performed on Transformer to calculate core losses at no load. As indicated by name Open circuit means transformer one winding is kept. So usually High voltage side is kept open as at load voltage and current readings are very low which could not be feasible to measure on high voltage side. So in this test High voltage winding is kept open and Voltmeter, Ammeter, Wattmeter are connected on Low voltage side and source of supply is also connected on Low voltage side for measurement of parameter. For short circuit test on Transformers visit:- http://electrialstandards.blogspot.in/2015/09/short-circuit-test-on-transformerswhy.html Connection diagram for the same is as shown below:- In open circuit test as discussed earlier that this test is performed on low voltage side so all measuring instruments are connected on low voltage side i.e. A voltmeter, wattmeter, and an ammeter are connec

There are many ways to water and energy saving that help to reducing water and electric bill and also help to environment. 29 tips briefly: 1-Using LED lamps rather than CFL or incandescent lamps. 2-Using auto light switch for garden lights. that turn on your garden lamps at night and turn off that in daylight automatically. 3- Using motion sensor switch help to optimizing electric consumption. 4-Solar energy can product all or some power needed in your home 5-Using solar water heater   6-Double glazed windows work as a heat insulator so doesn't allow to heat go outside in winner and doesn't allow to heat come inside in summer. 7-Don't run air conditioner and ceiling fan together because the ceiling fan push the heat air down.   8- Always set your conditioner in auto state then choose suitable temp. that you want. in this state the conditioner stops when arrive to that temp. so help to power saving.  9-New fridge always have an incandescent lamp that consume high power and