Hemant Savla

Stuff made by me before 2002 :-

1. CNC Drilling Machine :-  It is 3 axis stepper motor driven CNC (computer numerical controlled machine). Each axis is run by a Stepper motor which is run by a chopper designed by me. These three Choppers and various limit switches are all connected to a PC (486 based system) by a ISA interfacing card. Depending upon the clock pulse and direction signal given to the chopper system from PC; chopper generates corresponding signal which causes stepper motor to move forward or backward. Rotation motion generated stepper motors are converted linearly by ball screws precisely. Holes are drilled by High speed spindles manufactured by Kavo (a German company). Dust generated during drilling is removed by a vacuum cleaner which turned on and off by PC using a relay.  I wrote PC side software in C/C++. Teaching  function of this machines uses a CCD camera to point where hole is to be drilled. This system whole  system is working smoothly drilling about 40 holes per minute. (Look at the attached Photo)

2. Copper Thickness Meter :- Principle behind working of this meter is that as the thickness of the copper foil (present on the Base material used in manufacturing PCBs) increases its equivalent resistance decreases. On basis of  this principle various standard copper thickness 18μm, 35μm and 70μm are to distinguished.

3. Data Acquisition and Control Board :-  It was my final year project.This board  had eight 12-Bit ADC channels, eight On/Off switches, 1 DAC channel, 1 PWM channel and was connected to PC. With RS232 based serial link. In this project,  AT89C51 was used as microcontroller, AD574 as 12 bit Analog to Digital Converter, DAC0808 as   Digital to analog converter.  In this whole system PC acts as a Master and Controller Board acts as a slave which listens the commands given by PC and executes them. PC  end  software was written in JAVA and Visual Basic.

4. Digital Thermometer with LCD Display :-   This thermometer was made using  ICL7106 which is a three and half digit analog to digital converter with LCD display driver and semiconductor Ic transducer LM35 whose output voltage increments by 10mV/`C.

5. Atmel's AVR RISC microcontroller’s programmer :- It’s an In-circuit programmer made to program AVR microcontroller. Later I modified it to program 89S8252 (an 8051 class microcontroller)

6. Digital Clock :-  This clock was made using IC SC2504A from SCL India. Main features of this clock are each digit is of   Dimension 5 cm x 2.5 cm , each segment consisting of 4 leds and when ac power is not available its internal clock and time keeping circuits work on single 1.5 volt battery.

7. Four  Digit BCD Counter :-  This was my first electronic project in college and was a part of course work of subject El206 Digital Circuits. It was constructed using IC7490 a BCD Ripple Counter, IC7447 BCD to 7 segment decoder and IC555 which was configured as a clock of frequency 1Hz.