सोल्ड्रिंग ऑयरन का उपयोग कैसे करना सोल्ड्रिंग की विधि

सोल्ड्रिंग ऑयरन का उपयोग कैसे करना सोल्ड्रिंग की विधि

भूमिका:- इलेक्ट्रॉनिक प्रोजेक्ट में सोल्डरिंग का बहुत महत्व है।यदि ड्राई सोल्डर रह जाता है तो बाद में बहुत प्रॉब्लम होती है।
विधि:- सभी कम्पोनेन्ट की लीड को अच्छे से साफ करके टिनिंग कर लेना चाहिए। ऐसा करने से सोल्डरिंग के समय आसानी होती है
पीसीबी में कम्पोनेन्ट फिट करने के पहले ट्रेक को साफ करना चाहिये।
सोल्डरिंग करते समय पेस्ट का उपयोग आवश्यक है ।
इलेक्ट्रोलाटिक केपेसिटर में प्लस माईनस का ध्यान  रखना बहुत जरुरी है।

http://vijayelectronicsforu.blogspot.com/2018/08/star-delta-starter-principle-circuit.html

LCD INTERFACING WITH ARDUINO FOR MESSAGE DISPLAY

LCD INTERFACING WITH ARDUINO FOR MESSAGE DISPLAY

Introduction:- Liquid crystal display is used with microcontroller to display any message or digital output value. general purpose lcd has 2 row of 16 charactor to display. It is used as output display device. It has 16 pins for connection. pin 1 is connected to ground, pin 2 is connected to + 5 v, pin 3 is connected to potentiometer midile point for lcd contrast control,  pin 4 is Registor select pin for selecting data resistor or command Registor. pin 5 is read/write enable. pin 6 is enable pin. pin 7 to pin 14 are for data db0 to db7 respectively. Pin 15 is back light led plus and pin 16 is back light led minus.

Circcuit:- Arduino board and lcd display is to be connect as per circuit diagram given below. connect the board with usb cable to pc. copy and paste program given below in Arduino ide. compile and upload the program.liquid crystal libbrary is included in program. functions used are lcd.begin() to initialise lcd disply. lcd.print() to write  message in display memory. lcd.disply() to display message and lcd.noDisplay() to turn off message.

All comment are written in blue color and code is in white color.

/* code start  (multiline comment)
  LiquidCrystal Library - display() and noDisplay()

 Demonstrates the use a 16x2 LCD display.  The LiquidCrystal
 library works with all LCD displays that are compatible with the
 Hitachi HD44780 driver. There are many of them out there, and you
 can usually tell them by the 16-pin interface.

 This sketch prints "Hello World!" to the LCD and uses the
 display() and noDisplay() functions to turn on and off
 the display.

 The circuit:
 * LCD RS pin to digital pin 12
 * LCD Enable pin to digital pin 11
 * LCD D4 pin to digital pin 5
 * LCD D5 pin to digital pin 4
 * LCD D6 pin to digital pin 3
 * LCD D7 pin to digital pin 2
 * LCD R/W pin to ground
 * 10K resistor:
 * ends to +5V and ground
 * wiper to LCD VO pin (pin 3)*/
 

// include the library code:
#include <LiquidCrystal.h>

// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

// In setup()  we are using first function lcd.begin(16,2) to initilise lcd with 16 number of  //columns and 2 rows.
void setup() {
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // In lcd.print("hello, world") we give command to write hello world in display memory
  lcd.print("hello, world!");
}
//The code written in void loop() will repeat continouly
void loop() {
// the function noDisplay() is used to blank (turn off) the display message

  lcd.noDisplay();
  delay(500); // this provide delay of 500 mili second

  lcd.display(); // this function turn on display message
  delay(500); // this provide delay of 500 mili second
}
//code ends
// is used to write comment in side the code. The above code to be write on arduino ide compile and load on Arduino board. It will start displaying blinking "hello world" message on lcd display. You can change the message displyed by changing the parameter of lcd.print(" message to display") function. This post will be help full . please comment for any quary and suggestions for improvement.



http://electronicsandmicrocontroller.blogspot.com/2018/07/a-simple-arduino-program-blinking-led.html

Variable frequency variable voltage VVVF

Variable frequency variable voltage VVVF

Introduction :- The motor used in any machine need to be operate at variable speed.Earlier DC motor was used for applicatios where speed control is requred. The speed of ac motor is considered as fixed speed because the speed is depend upon number of pole and frquency of supply. But now a day with invent of VVVF drive it becomes easy to control speed of motor by producing variable voltage variable frequency supply for motor.
Working:-

In VVVF drive three phase voltage is converted in to dc voltage generally 500  v dc. Then three phase inverter circuit is used to produce 3 phase ac supply of  varable frequency and variable voltage. Voltage to frequency ratio remains constant.It uses digital control system for firing control of IGBT and inverter parameter setting. All the data of motor (such as voltage current rpm)  and operational requirements are  stored in parameters of drive.  VVVF drive has a display and key pad which are used for parameter setting. During running of motor running data load current and fault candition is also displayed on display. Drive key pad has buttons for start stop local remote forward reverse etc. In addition to this external push buttons can also be connected in control terminal block for start stop speed increase decrease etc. drive has three power terminal nuetral terminal and earth terminal for input connection. similarly three power terminal and one earth terminal for motor connection.

different makes of drive has some difference in control terminal block connection but basically all are same. With the help of instruction manual given with drive and following all instructions care fully it is easy to use VVVF drive for speed control of ac motor application. please see my blog for more articles. your comment and suggestions are welcome.