TEMPERATURE SWITCHING ANALYZER

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TEMPERATURE SWITCHING ANALYZER

Mrs. S. J. KULKARNI, PROF. S. N. PAWAR, Ms. M.S.TADPATRIKAR

ABSTRACT:Electrical characterization, such as measurement of the I-V characteristics of electronic devices with respect to change in temperature is

necessary for application of such devices. In our project, we report the development of a simple low-cost system for the measurement of I-V characteristics associated with changing surrounding temperature. The temperature switching analyzer developed basically consists of a PIC micro controller based Master/Slave configuration for monitor and control for electronic devices along with high-speed data acquisition system. The design aspects of the system, its interface.' to the high-speed data acquisition system and the personal computer, and the details of the application software developed are described.

KEY WORDS: I-V characteristics, PIC micro controller, Temperature switching analyzer

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1. INTRODUCTION

The aim is to design and implement a simple low cost Electrical/Electronic temp switching analyzer. The hardware components of the system consists of micro controller based Master/Slave configuration for temp monitor and control and a high-speed data acquisition system for current and voltage ratings. The Master controller is designed for temperature monitoring and is visualized by LCD. LM35 is used as a temp sensing device. As the temperature monitored and when the upper and lower cut off temp is set the heating chamber power is made on until the max temp is reached. As the max temp is obtained the AC power is made off. Relays are used to control these actions. The Master PIC microcontroller controls three relays; one of them is used for controlling the heating chamber operation. Second and Third relay are used to operate the temp sensing electronic devices. The analog values given out by the temp sensing devices are converted to digital signals and passed to computer through serial communication protocol. The Slave PIC microcontroller does the operation of digital conversion of analog inputs coming in from two channels. A switching mechanism is utilized here so that the DAC comes into picture and the Slave generates sine, square, triangular waves. The application software is continuously waiting for the digital data coming from the hardware and is designed to develop the graphical presentations such as 1) Voltage v/s Time 2) Current v/s Time 3) Voltage v/s Current. The application s/w is developed in VB6.0. It is designed to generate the respective characteristic graph as well as it has got facility to store the data in database and resume when ever required.

2. FEATURES OF THE PROJECT

The protocol developed consists of various electronic monitoring and controlling protocols like-

a) It can work as computer operated digital thermometer for indication of room temperature as well as storage of the variations with respect to time.

b) A PIC16f 877A microcontroller based Master temperature controlling device which controls the heating chamber switching.

c) 16x2 LCD display to display the temperature.

d) A Sine, Triangular and square wave generation using DAC 0800.

e) The application software can also be used as signal storing device as the signal coming in digital binary form is stored and can be re produced as per requirement at times.

3. FUNCTIONAL BLOCK DIAGRAM

Fig.1 shows the block diagram of Electrical/ Electronic switching analyzer. The various blocks are explained as follows. The design of each sub-block is also explained. A. Signal conditioning block

Signal conditioning is widely used term in the world of data acquisition. The most common transducers produce an output in the form of voltage, current, charge, capacitance and resistance. However, we need to convert these signals to voltage in order to send input to A-to-D converter. This conversion is commonly called as signal conditioning. The Temperature sensors components used in the protocol are LM-35

B. Microcontroller-Based Wave Form Generation Source

The microcontroller-based Wave Form Generation source is designed to function as a programmable voltage Wave Form Generation source depending on the parameter given through hyper terminal. This unit has features to generate different types of waveforms such as triangular, ramp, step. etc. with single or multiple cycles. The instrument receives the commands from the computer through the serial port and outputs the required different types of waveforms such as triangular, ramp, step. etc

___________________ 1. Mrs. S. J. KULKARNI, 2. PROF. S. N. PAWAR 3. Ms. M.S.TADPATRIKAR

1. Sr. Lecturer, E & TC Dept., P.D.V.V.P. Polytechnic, Loni. 2. Asst. Prof., E & TC Dept. , JNEC, Aurangabad.

3. Sr. Lecturer, E & TC Dept., Modern College of Engg, Pune.

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C. Microcontroller-Based Temperature controller and Monitoring System

It consists of a transformer, rectifier, filter, a digital-to-analog converter (DAC).A in build ADC module, A pair of PIC 16f877 microcontroller boards in master slave configuration for intelligent control, Relay board with relay drivers an RS-232 driver to interface to the computer, and the associated power supplies.

D. PIC micro controller

Microcontroller is the heart of this system. It handles all the operations of the system. In this dissertation PIC16F877 is used. It is a 8-bit PIC microcontroller (PIC16F877) having 16-kB EPROM, 256-B RAM, three 16-bit timer/counters, and four 8-bit bi-directional ports.

4. HARDWARE DESIGN

The Master PIC microcontroller controls three relays; one of them is used for controlling the heating chamber operation. Second and Third relay are used to operate the temp sensing electronic devices. The analog values given out by the temp sensing devices are converted to digital signals and passed to computer through serial communication protocol.

The Slave PIC microcontroller does the operation of digital conversion of analog inputs coming in from two channels. A switching mechanism is utilized here so that the DAC comes into picture and the Slave generates sine, square, triangular waves. Thus the project can be viewed as consisting of four modules, namely,

Master Temperature Monitoring Unit Master Temperature Controlling Unit

Slave ADC and Serial communicating protocol Slave Waveform Generator Unit

Following figure shows block diagram for Electrical /Electronic Temperature Switching Analyzer.

Figure 1: Block Diagram of Electrical /Electronic Temperature Switching Analyzer

230/ACHeater Electronic Component

230V AC MASTER

PIC 16F877A

LCD

Relay Driver

Relay

LM35 Signal

Conditioning

Power Supply

PIC 16F877A

Waveforms

Application Software

Max 232 or Transistor

Relay Power

Source

Relay Power

Source Power

Supply

Signal Conditioning for Electronic Component

DAC

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Microcontroller Interface

To LCD Pin 4(RS)

C

R4

RESISTOR SIP 10

1 2 3 4 5 6 7 8 9 10 R9 RESISTOR D7 DIODE ZENER

To LCD Pin 12(D5)

C1 1000UF/25V D3 DIODE VCC D2 DIODE C R8

RESISTOR SIP 9

1 2 3 4 5 6 7 8 9 R12 RESISTOR C R7 RESISTOR SIP 9

1

23456789

R1 10K

VCC

To LCD Pin 13(D6)

VCC C7 CAP NP J9CON12 1 2 3 4 5 6 7 8 9 10 11 12 C4 CAP NP

To LCD Pin 6(E)

C3 CAP NP U2 LM7805C/TO 1 3 2 IN OUT GN D C6 CAP NP VCC U1 AT89S8252 9 18 19 20 30 24 31 40 1 2 3 4 5 6 7 8 21 22 23 25 26 27 28 29 10 11 12 13 14 15 16 17 39 38 37 36 35 34 33 32 RE1/WRBar/AN6 RC3/SCK/SCL RD0/PSP0 RD1/PSP1 RD7/PSP7 RC5/SD0 VSS RB7/PGD MCLR/VPP RA0/AN0 RA1/AN1 RA2/AN2/VRef -/CVRef RA3/AN3/VRef + RA4/TOCKI/C1OUT RA5/AN4/SSBAR/C2OUT RE0/RDBar/AN0 RD2/PSP2 RD3/PSP3 RC4/SDI/SDA RC6/TX/CK RC7/RX/DT RD4/PSP4 RD5/PSP5 RD6/PSP6 RE2/CSBar/AN7 VDD VSS OSC1/CLKI OSC2/CLKO RC0/T1OSO/T1CKI RC1/T1/OSI/CCP2 RC2/CCP1 RB6/PGC RB5 RB4 RB3/PGM RB2 RB1 RB0/INT VDD

To LCD Pin 14(D7)

J4 CON3 1 2 3 VCC Q1 BC547 1 2 3

To LCD Pin 11(D4)

D6 DIODE VCC D1 DIODE R10 RESISTOR VCC VCC J1 CON2 1 2 R11 RESISTOR J10 CON10 12345678910

VCC VCC C2 470UF/25V J3 CON6 123456

C5 CAP NP

To Relay Con J1 Pin1

VCC

To J15 Pin1(O/P of Temp Sensor 1)

VCC J2 CON10 1 2 3 4 5 6 7 8 9 10 C R5

RESISTOR SIP 9

1 2 3 4 5 6 7 8 9 J11 CON10

12345678910

D4 DIODE Y 1 CRY STAL R2 RESISTOR VCC D5 LED Q2 BC547 1 2 3

Figure 2: Master PIC Board circuit Diagram:

U1 AT89S8252 9 18 19 20 30 24 31 40 1 2 3 4 5 6 7 8 21 22 23 25 26 27 28 29 10 11 12 13 14 15 16 17 39 38 37 36 35 34 33 32 RE1/WRBar/AN6 RC3/SCK/SCL RD0/PSP0 RD1/PSP1 RD7/PSP7 RC5/SD0 VSS RB7/PGD MCLR/VPP RA0/AN0 RA1/AN1 RA2/AN2/VRef -/CVRef RA3/AN3/VRef + RA4/TOCKI/C1OUT RA5/AN4/SSBAR/C2OUT RE0/RDBar/AN0 RD2/PSP2 RD3/PSP3 RC4/SDI/SDA RC6/TX/CK RC7/RX/DT RD4/PSP4 RD5/PSP5 RD6/PSP6 RE2/CSBar/AN7 VDD VSS OSC1/CLKI OSC2/CLKO RC0/T1OSO/T1CKI RC1/T1/OSI/CCP2 RC2/CCP1 RB6/PGC RB5 RB4 RB3/PGM RB2 RB1 RB0/INT VDD D5 LED C R7 RESISTOR SIP 9

1

23456789

VCC VCC VCC VCC C R4

RESISTOR SIP 10

1 2 3 4 5 6 7 8 9 10 J2 CON10 1 2 3 4 5 6 7 8 9 10 Q1 BC547 1 2 3 VCC D2 DIODE J9CON12 1 2 3 4 5 6 7 8 9 10 11 12 R2 RESISTOR C4 CAP NP C5 CAP NP D1 DIODE VCC C3 CAP NP R10 RESISTOR VCC C2 470UF/25V D4 DIODE J1 CON2 1 2 C6 CAP NP R1 10K VCC VCC D6 DIODE D3 DIODE R12 RESISTOR J4 CON3 1 2 3 Q2 BC547 1 2 3 D7 DIODE ZENER J11 CON10

12345678910

C1 1000UF/25V R9 RESISTOR C7 CAP NP VCC C R5

RESISTOR SIP 9

1 2 3 4 5 6 7 8 9 J3 CON6

123456 To J10 Pin1(O/P of Temp Sensor 3)

C

R8

RESISTOR SIP 9

1 2 3 4 5 6 7 8 9 U2 LM7805C/TO 1 3 2 IN OUT GN D

VCC

J10

CON10

12345678910

Y 1 CRY STAL

R11 RESISTOR

VCC

To J8 Pin1(O/P of Temp Sensor 2)

VCC

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+12 V

+

-U6 OP-07

3 2 6

7

1

4

5

R1 RESISTOR

U3

DAC0808

1 2

6

9 11 15

10 13 12 14

5 3 4

7 8

16 NC

Gnd

A2

A5 A7

VR-A6 Vcc A8 VR+

A1 VEE IOut

A3 A4

Comp _R3

5K

-12 V

C2 0.1uf

+10 V +12 V

R2 RESISTOR

C1 0.1uf

J3

CON8

1 2 3 4 5 6 7 8

-12 V

R4 5K

Figure 4: Wave Form Generation DAC0808 Circuit Diagram

U6-LM358

LM358 4

7 5 1

2

6 3

8

-VCC

Output B

Non Inv I/P B Output A

Inv I/P A

Inv I/P B Non Inv I/P A

VCC

U10-LM358

LM358 4

7 5 1

2

6 3

8

-VCC

Output B

Inv I/P A

VCC

J10 O/P Con

1 2

VCC

R11 POT

1 3

2

R18 POT

1 3

2

Temp Sensor Signal Conditioning Circuit

J8 O/P Con

1 2

U5-LM35

LM35

2

3 1

GN

D VOUT

+5V

J9 +5V Cons Voltage

1 2 J7 +5V Cons Current

1 2

J14 +5V 1 2

U3-LM35

LM35

2

3 1

GN

D VOUT

+5V

U9-LM35

LM35

2

3 1

GN

D VOUT

+5V

U4-LM358

LM358 4

7 5 1

2

6 3

8

-VCC

Output B

Inv I/P A

VCC

R9 POT

1 3

2

R19 RESISTOR R10 RESISTOR

J15 O/P Con

1 2 R12 RESISTOR

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5. SOFTWARE DEVELOPMENT

The application software for the total system consists of master slave modules, the code for the PIC-microcontroller master temperature monitor and control and the slave for analog to digital conversation of the received voltage and serial transmission to generate the necessary plots on computer. The slave is also designed to generate various user required waveforms. The software at the PC end providing the user interface, and also the protocol for communication between the PC and the Master and slave microcontroller unit.

ALGORITHM

1. Start.

2. Handshaking initialization (ctrl + A).

3. Input range for temperature controlling via serially. 4. Increase temperature of temperature sensor. 5. Continuously compare temperature ranges.

6. if(adc_val > l value && adc_val < U_value).Then SET temperature, Voltage, current relays ON.

7. Else SET them OFF.

8. Transmit both voltages and current value via serially 9. Plot the respective graphs on VB.

10. Generate the readings table using VB.

Waveforms generated

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Table 1: Current and Voltages for temperature range between 31ºC to 61°C.

7. CONCLUSION

An electrical/ electronic temperature switching analyzer has been developed for obtaining the I-V characteristics of temperature sensing electronic devices. This unit has additional feature to generate different types of excitation waveforms such as triangular ramp, step, etc., with single or multiple cycles and programmable sweep rate. This protocol will be a complete solution for an application development electronic industry for testing the electronic device under various temperature conditions and variable waveform input.

8. REFERENCES

1. Chitters Nagaraja Murti, Sharma Ramgopal, S. Ashokan, “Simple Low Cost Electrical Switching Analyzer for I-V Characterization of Switching Samples And Devices” IEEE transaction on Instrumentation and Measurement, Vol, 55, No.1, February 2006, pp-248-256. 2. PIC16F877 Data Sheet by Microchip.

3. National semi-conductors data sheets.