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Showing posts from August, 2019

Closed loop Control of DC to DC boost converter

DC-DC boost converter boosts the DC input voltage to higher DC voltages  according to the duty cycle of  PWM  applied to the mosfet used to charge the inductor.While the mosfet state is on the inductor gets charged, than when the mosfet turns off the voltage stored in inductor and input voltage gets added and appears in the output. But if only these components are used output Voltage will be pulsating and have a frequency similar to that of mosfet switching. So we need to put a capacitor in output in order to oscillating output to smoother output. Still the stored voltage in capacitor will backflow through the mosfet when it is on, So we need to place a diode in between mosfet and capacitor in order to prevent backflow of stored charge in capacitor.After these circuit requirements are completed the boost converter will be boost low voltage DC input to higher DC voltages.The circuit should look like as shown below:- Boost Converter Circuit Output Voltage calculation The

DC-DC buck converter

DC-DC buck converter converts DC voltage from higher voltages to lower voltages according to the duty cycle of PWM applied to the MOSFET gate. When MOSFET  is fired the inductor and capacitor gets charged so when MOSFET turns off the inductor and capacitor works as current and voltage source and continue to supply steady voltage and current till the MOSFET is fired again. For the inductor and capacitor to continuously supply the power to load without any ripples the inductance and capacitance of inductor must be high enough so that the change in their voltage and current is not  significant.  Buck converter circuit output voltage  the output voltage of the converter depends on the duty cycle of the PWM applied to the MOSFET gate.    output voltage  =  Duty cycle * Vin    Duty cycle        =  Ton/(Ton+Toff) with the change in load and change in input voltage the output voltage may vary, if load increases the output voltage will decrease as the capacitor cannot

Seven segment tempersture measurement circuit

this circuit can measure the environmental temperature. It consists of LM35 temperature sensor. Atmega328 micro controller is used to read analog data from data pin of the sensor and convert the data to temperature according to the conversion factor provided in datasheet. To make this project following components will be needed Atmega328 microcontroller crystal(16 MHZ) capacitor 22PF Seven segment display Matrix board lm35 temperature sensor Wire up the microcontroller as follows  connect (A,B,C,D,E,F,G,Dp) of seven segment to (3,7,4,2,1,5,6,0) and enable pins (D1,D2,D3,D4) to (13,A3,A2,12) with 470 ohm resistor between each four pins. And connect the  lm35 signal pin to A0 of the microcontroller. Than  program the  Microcontroller with following code after the circuit is complete. #Download Sevseg library from library manager #include <SevSeg.h> SevSeg sevseg; float a = 0; void setup(){   byte numDigits = 4;   byte digitPins[

Patient Health Monitoring System

Patient Condition Monitoring System is a system that is developed to monitor the different health parameters of multiple patients simultaneously by a single person. The system can give warnings about the condition of patient if any parameter goes below lower threshold or above the upper threshold. The goal of Patient Condition Monitoring System is to develop a simple, reliable and economical monitoring system which measures different types of health parameters like heartbeat, temperature and movement of the body. The project Patient Condition Monitoring System has been selected because of the interests and opportunities it provides in the field of health and biomedical engineering. Following application is developed to monitor the data    the system works as follows  Heart beat sensor senses the change in color of the blood on accordance of pulse rate. The observed data is sent to the microcontroller that converts it into the standard unit. With the help of display, t