[Qaisar]

transistor has only two PN-junction .

base-Emitter junction and Base- collector jumction .

there is no PN junction between emitter and collector.

transistor can be represented by diode equivalent cct.

 

to use transistor as a amplifier its base emitter junction is forward biased and base collector junction is reversed biased. now how the base collector is reverse biased .

A PN junction is said to be forward biased when anode is at 0.7v higher then cathode.

now look at ur diagram .

collector bias voltages(VCC)  are at higher potential then base voltage so cathode of base-collector junction is at higher potenial then anode so this junction is reverse biased. 

hope u got it…

 

wysiwyg_imageupload:3615:

  

 

 

 

[Qaisar]

use any circuit from these 2

wysiwyg_imageupload:3434:

 

 

[Qaisar]

wysiwyg_imageupload:3431:

[Qaisar]

there is no need to use microcontroller to control relay through IR ..

if u need any diagram of IR tranciever , i can provide free of cost…

u can also google it …

[Qaisar]

 

dig_ctrl_var = vote_amt[p]+48;  ?



lcd display ascii character.

48 = 0 in ascii

how u will display 5 on lcd?

 

simple

add 5 in 48 =53

53 decimal charatcer is equal to 5 in ascii characters.

have a look on ascii table . just google it ..

 

the above statemnt is taking a number from a array , converting that number to ascii and copy to  dig_ctr_var.

[Qaisar]

hi 

 that code dosent have any problem at all. i dont know why you have 26 errors…

which compiler you are using ?

 

[Qaisar]

hi lee. 

 i think u r using s52 . this code will for s52 too . 

tha above code is correct as i shown its simulating diagram  . i modified delay function .simulate this code now and run it on proteus . 

but plz follow the above diagram to run this code . 

 

 

 

#include <AT89X51.H>

 

#define lcd_data P2

sbit en=P0^1;

sbit rs=P0^0;

 

 

unsigned char z;

unsigned int i;

 

 

 

void delay(unsigned int time)

 {

   unsigned int i,j;

   for(i=0;i<time;i++)

   for(j=0;j<1275;j++);

   }

         void lcdcmd(unsigned char value)

        {

              lcd_data=value;

               rs=0;

  en=1;

  delay(100);

  en=0;

  return;

 }

 

void lcddata(unsigned char value)

{

  lcd_data=value;

rs=1;

en=1;

delay(100);

en=0;

return;

   }

 

void main(void)

{

   lcdcmd(0X38);//5X7 matrix

  lcdcmd(0X0E);//lcd on ,curor on

  lcdcmd(0X01); // clear lcd command

  lcdcmd(0X80);//move cursor to line1

 

  {

unsigned char name[]=” TEST PROGRAMME “;

 

for(z=0;z<=16;z++)

lcddata(name[z]);

 

  lcdcmd(0XC2); // move cursor to line2, position 2

 

for(i=48;i<=57;i++)   

  lcddata(i);

 

while(1);

 }

 

} 

 

[Qaisar]

use above diagram . i have already use this cct. 

 u can use any TV remote to ON/OFF ur electrical appliances. if u want to make ur own transmitter , i have long range transmitter ..

that works for more then 30 ft . if u need i will put here that cct too.

 

regards…

[Qaisar]

wysiwyg_imageupload:3203:

[Qaisar]

my.h is delay file that exist in my Ex1 folder .

open kiel folder then open  my Ex1 ,

copy my.h file to ur project …or just use ur own delay routine…

 

[Qaisar]

plz put declaration part of ur code.

 things will connect as u define them in code ..

 

 

 did u write that code urself or copied from web?

[Qaisar]

these are 4 channel IR/RF tranciver ic’s. u can use it to build 4 channel IR/RF remote control. but this pair of ic’s is expensive .

[Qaisar]

black boxes means data is not transfering to lcd ..

visit post ”lcd interfacing to 8051 by qurat ain” i put code and diagram there. 

first try that code and diagram . if still u r unable to interface lcd then check ur haedware and lcd connection.

[Qaisar]

black boxes means data is not transfering to lcd ..

visit post ”lcd interfacing to 8051 by qurat ain” i put code and diagram there. 

first try that code and diagram . if still u r unable to interface lcd then check ur haedware and lcd connection.

[Qaisar]

follow this code and diagram to display text and numbers on lcd..

 

 

#include <AT89X51.H>

#include < my.h > // built in delay function

 

#define lcd_data P2

sbit en=P0^1;

sbit rs=P0^0;

 

 

unsigned char z;

unsigned int i;

 

         void lcdcmd(unsigned char value)

        {

              lcd_data=value;

               rs=0;

  en=1;

  delay(200);

  en=0;

  return;

 }

 

void lcddata(unsigned char value)

{

  lcd_data=value;

rs=1;

en=1;

delay(200);

en=0;

return;

   }

 

void main(void)

{

   lcdcmd(0X38);//5X7 matrix

  lcdcmd(0X0E);//lcd on ,curor on

  lcdcmd(0X01); // clear lcd command

  lcdcmd(0X80);//move cursor to line1

 

  {

unsigned char name[]=” TEST PROGRAMME “;

 

for(z=0;z<=16;z++)

lcddata(name[z]);

 

  lcdcmd(0XC2); // move cursor to line2, position 2

 

for(i=48;i<=57;i++)

  lcddata(i);

 

while(1);

 }

 

} 

 

 

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