Project Work

PCB Designing And AC/DC Power Supply Circuits

Micro-inverter

Microcontroller I/O Programming

P i t d i it b d (PCB)Printed circuit board (PCB)

Printed Circuit Boards are made specifically for each circuit. It p ygives a compact and wire free circuitry. A simple PCB is shown in the figure.

Procedure for making PCBA computer aided design software is used for making theschematic and layout of circuit.

Schematic Design

The schematic of circuit is made by using the capture CIS whichis a part of OrCAD software It is done by using the library tools Thisis a part of OrCAD software. It is done by using the library tools. Thislibrary is provided with the design of all type of electroniccomponents. After placing the components wiring is done.

Layout Design

Once the schematic is completed, the layout is made in the layoutpart of OrCAD software. Layout components are provided in itslibrary but can also be created by our own using library managerlibrary but can also be created by our own using library managertoolbox. Footprints are made by proper scaling of the components.

After completion of layout, the print is taken on a glossy paper using a laser printer.

Transfer of Design by Ironing

The layout design is transferred on the copper clad board by placing it facing the printed side of paper followed by ironing.

Peeling of Paper

After ironing, peeling is done by dipping the clad board in water. When the paper gets soften, peel it off.

Drilling and Etching

Drill the PCB using a hand drill. The size of the hole must be of the order of 1mm.This can be done by using 1mm bit.

Ferric Chloride FeCl3 (anhydrous) can be used as an etchant. P t th PCB i th l ti t t h thPut the PCB in the solution to etch the copper.

Summary

The following steps are used to a make PCB:

We use software, like Or CAD to draw the schematic of circuit.

Then we make the layout of that circuit.

After that print the PCB design using a laser printer.

And then take impression of the circuit design on a copper p g ppclad board.

Remove the excess copper using etching processRemove the excess copper using etching process.

Precautions

The mirror image of PCB layout will always beimprinted on copper side.

Always print from a laser printer.

There are standards for using traces e.g. for singletracks, for ground and power etc.

T ki f l ll d ll l i ll dTracking from large to small and small to large is callednecking.

Printing can be done on both sides for do ble la eredPrinting can be done on both sides, for double layeredPCB providing the board must have copper on bothsides.

Triple Power SupplyIts a multipurpose power supply which fulfills the requirements ofIts a multipurpose power supply which fulfills the requirements of laboratory experiments. Output of ± 12V, ± 5V and +1.25 to +20V can be taken using this power supply.

Micro Inverter

An inverter is a device that converts dc power into ac power atdesired output voltage and frequency. There are generally twotypes of inverters:

( ) Li t t d i t(a) Line commutated inverters :voltage level, frequency and waveform on ac side cannot bechangedchanged.

(b) Force commutated inverters:provide adjustable output ac voltage and frequency

Battery charging circuit for Micro Inverter

B tt l l i di t d i t i itBattery level indicator and inverter circuit

AVR Microcontroller Programming With

Ph i MDKPhoenix-MDK

Phoenix Microcontroller Development KitPh i i ll d l ki (PMDK)Phoenix microcontroller development kit (PMDK)Consists of an ATmega16 MCU. All the I/O pins of the MCUare available on sockets. The kit can be programmed throughp g gPC parallel port by connecting it to the six pin whiteconnecter provided in the kit.

Cable Connection Configuration

Pin out diagram of ATmega16 and thePin out diagram of ATmega16 and theminimum circuit required to get started

Program To Glow The LED’s Sequentially (A simulation of sequence for running a stepper motor)(A simulation of sequence for running a stepper motor)

#include <avr/io.h>void delay (uint16_t itime)

{{Volatile uint16_t i,j; for (i=0;i<itime;i++)for (j=0;j<1275;j++);for (j=0;j<1275;j++);

}int main (void)

{DDRB = 0x0f;DDRA = 0x00;;

For (;;){

if (DDRA= =0)if (DDRA 0){

PORTB = 0x03;d l (1000)delay(1000);PORTB = 0x06;delay(1000);PORTB = 0x0c;delay(1000); PORTB = 0x09;PORTB 0x09;delay(1000);

}

if (DDRA==1){{PORTB = 0x09;delay(1000);PORTB = 0x0c;delay(1000);PORTB = 0x06;;delay(1000); PORTB = 0x03;delay(1000);delay(1000);}

}}

Program to display the data on LCDProgram to display the data on LCD

#include “pmdk_lcd.c”

Int main()Int main()

{Lcd_init();

lcd put string(“Electronics”);lcd_put_string( Electronics );}

The file pmdk_lcd.c provides the following functions:

Lcd init ( ) : Initailizes the LCD display must be called once inLcd_init ( ) : Initailizes the LCD display, must be called once in the beginning

Lcd_clear ( ) : Clears the display

Lcd put char (char ch) : Outputs a single character to the LCDLcd_put_char (char ch) : Outputs a single character to the LCD display

lcd put string (char* s) : Displays a string to the LCDlcd_put_string (char* s) : Displays a string to the LCD

lcd_put_byte (uint8_t i) : Displays an 8 bit unsigned integer

lcd_put_int (uint 16_t i) : Displays a 16 bit unsigned integer