Title of Invention

COMPUTERIZED THERMOMETER

Abstract

A computerized thennometer consisting of timer circuit, thennistor ( Positive Temperature co-efficient resistance) and capacitance connected with parallel port for measuring temperature will get input trigger from prewritten instructions and return digital pulse as the output to the circuit handling instructions and the instructions calculate the temperature of the atmosphere using the length of the pulse which varies on the resistance value available on thermistor resistance during that moment. The circuit gets the negative pulse as input from instructions. Resistance of thennistor varies depending on the temperature to produce a variable pulse length. Length of the pulse will be measured in milliseconds. Initially, the number of millisecond associated with number of centigrade is fed to the computer manually. Based on the available data the instructions will display the temperature in centigrade. This invented computerized thennometer consists of hardware along with the instructions in order to perfonn the function of the hardware.

Full Text

a. Field of inVention b. Novelty of invention c. Background of invention with regard to the drawback associated with prior art d. Object of invention e. A summary of invention f. Description of the Flow chart and Drawings a. Field of invention Since this invention is based on computer to find the temperature of atmosphere the field of invention can be called as " COMPUTER FIELD b. Noveltv of invention This computerized themiometer can work with any other computer in this world and enables that computer is capable of displaying atmospheric temperature irrespective of its Hardware architecture. c. Background of invention with regard to the drawback associated with prior art In our day-to-day life, we get the time and date from all the computers available in this world. Apart from Date and Time, The objective of this invention is to get the temperature also from every computer available. To find atmosphere temperature Super computers, Thermo controller devices are available but they will use ADC (Analog to Digital Converters) to identify the analog signal, which will be tedious process. They will not fit into all the computers but this computerized thermometer circuit will fit in any of the computer and enables that computer capable of displaying temperature. This newly invented computerized thermometer uses the timer circuit with the thermistor and the capacitance to help the computer to get the digital signal according to the temperature. Cost of this circuit compared to any other prior model is very less. This circuit can fit into any other computer irrespective of its Hardware architecture. d. Object of invention The entire computer in this world should be capable of displaying the temperature of the atmosphere at the lowest cost. e. Summary of invention The computerized thermometer consists layout of timer circuit, thermistor and capacitance connected with computer parallel port. This circuit will get the input trigger from computer software (whenever the temperature is needed to the computer) and DC 5V current from battery. Thermistor, which have been attached to this circuit will take the atmospheric temperature as the input and according to that input Termistor will vary its resistance. The circuit will give the digital pulse as the output to the computer. The length of the pulse will be measured with the help of the software. Depending on the resistance value of the thermistor length of the pulse varies and Depending on the atmospheric Temperature value of the thermistor resistance varies. In the software. Length of the pulse will be measured in milliseconds. Initially, the number of millisecond associated with number of centigrade is fed to the computer manually. Based on the first time data software will display the temperature in centigrade. This invented computerized thermometer consists of hardware along with software in order to perform the fimction of the hardware. f. Description of the Flow chart and Drawings This section explains layout and architecture of computerized thermometer and how it works with the help of circuit, thermistor and computer software. List of figures, which we have. Fig. 1. Layout of circuit and connection with computer parallel port Fig.2. Block diagram of major components of computerized thermometer Fig. 3. Architectural context diagram Fig. 4. Method of computing temperature in computerized thermometer The following section will explain whole functionality of the computerized thermometer as well as its working. Fig. 1. Layout of circuit and connection with computer parallel port The figure. 1 shows the layout of the computerized thermometer connected with parallel port of any computer. Where as in Fig. 1 different components are denotes as follows, P - is a printer parallel port of the computer which contains 25 pins B - 5 volt battery PTCR - Positive temperature co-efficient resistance ( 10k Ohms ±1% at 25°C Thermistor ) LED - Light Emitting Diode IC - Integrated Circuit 555 WB - denotes wooden box which has six connectors wbl, wb2, wb3, wb4, wb5 and wb6. Wbl - is connecting to the printer port pin 3 and positive voltage from battery B. Wb2 - is connecting to printer port 18-ground pin and ground of the battery B. Wb3 - is connecting to printer port pin 11 busy Q. Wb4 - is connecting to printer port pin 1 strobe. Wb5 - is connecting to one side of PTCR Wb6 - is connecting to other side of PTCR R - Resistance of 1 K ohms CI - Capacitance 100 Micro Farads C2 - Capacitance .01 Micro Farads Vcc - Connecting to Positive side of battery GND - Connecting to ground of battery Circuit description: Timer is a very popular integrated circuit, which is used, in both the analog and digital circuit. This timer IC can be used for both the monostable and astable models. Here, we are using as monostable model. It will take the input as low state and generate the output as high. A monostable multivibrators using Timer IC as shown in Fig. 1, is a basic circuit. A monostable multivibrator has only one stable state. The output during this stable state is low (about OV or ground). This can be identified by LED, which will not glow at this time. When the computer software triggers the circuit, then the output goes high for a predetermined time, which depends on the RC-time constant. During the above time LED will glow. After this time the output retums to its stable state, once triggered, the monostable multivibrator will not respond to any other input trigger pulse until it has completed it's predetermined timing cycle. The input signal or the trigger pulse is applied at pin no. 2. The trigger signal passed from the software to circuit via parallel port strobe pin.L The reset pin no. 4 is connected, together with the pin no. 8 to +VCC and printer port 3. The threshold pin no. 6 and the discharge pin no. 7 are connected together to +VCC through a PTCR. An extemal capacitor pin no. 5 is connected to ground through a capacitor C2. The output is available at pin no.3 and it is connect to the printer port pin no. 11. At the start of the cycle the output remains low and the capacitor CI remains discharged. When a negative moving pulse is applied at pin no. 2 then the output becomes high and the capacitor CI starts charging towards +VCC. When the voltage at pin no. 6 becomes 2/3 VCC then the output becomes low and capacitor CI is discharged. Width of the output pulse is given by the following formula. T=l.l(RlxCl) Where T = Time in seconds, Rl = Resistance in ohms and CI = Capacitance in Farads. For better performance the values of PTCR should be kept between lOOK and lOM. While, value of CI should be kept between lOOPF and lOOMF. Referring to the figure. 1, The content of dotted block are actually housed in a wooden Box. It has six terminals ( LVcc ,2.Gnd,3.Input trigger, 4.Pulse output, 5.Input to the thermistor, 6. Output from the thermistor). The Wooden Box wire number wbl is connected to the parallel port of computer pin no3. The box wire number wb2 is connected to the paralle port pin no. 18. The Box wire number wb3 connected to parallel port of pin no.ll. Similarly wire wb4 is connected to pin 11. The box wire no 5 & 6 are connected to the input and output of the PTCR. The working principle of this device is that a signal is sent to the interface device from the computer through parallel port pin nol. The circuit is enabled and it will give a output pulse and the output signal is send to the computer through the parallel port pin no.ll. Using specialized system software (This explained in detail in algorithm and the flowchart) these signals are measured and the equivalent temperature is displayed. Printer port pin details: This section gives printer port pin details and it will help us to understand the details about pins we used for our circuit interface. A standard PC provides for three printer ports at the following base address: LPTl = OX0378 OR 0X03BC LPT2= 0X0278 OR 0X0378 LPTl = OX 0278 In our module LPTl is at 0 x 0378 the printer port has three 8-bit registers: Pin 18-25 are connected to ground of computer circuit. In our circuit input trigger is connected to the strobe signal in pin no.l. The circuit output will be connected to busy signal pin no. 11 and the circuit ground is connected to ground signal pin no. 18. The circuit VCC will be connected to pin no.3. Fig,2. Block diagram of major components of computerized thermometer Referring figure no.2, It is a block diagram of the overall system. It consists of a PC, an interface circuit, and transducer (Positive Temperature Coefficient Resistance). The atmosphere heat is observed by the transducer and according to that the resistance of the transducer will vary. Where in Fig. 2 different components denotes as follows, PC - Any configured computer ID - Interface Circuit PTCR - Positive temperature co-efficient resistance Whenever PC wants to display the temperature it will trigger the Interface circuit by strobe signal. Interface circuit will responds to the computer with output signal based on the PTCR resistance. At the same time software will listen at the busy port 11. And calculate the time taken between trigger and complete response. Based on this time interval temperature will be displayed. Fig, 3, Architectural context diagram Referring figure. 3, It is the Architecture context diagram of overall system. Here ii,i2 in are the different temperature input to the PTCR. ri is the resistance which depends upon input ij , pi is the power signal of the circuit given to the computer parallel port, with respect to ri , I is the interface circuit. Q is the temperature output display of the computer. Where as in Fig. 3 different components denotes as follows, PTCR - Positive Temperature Co-efficient Resistance PC - Any computer with parallel port I - Interface circuit i1, i2 in - Are different atmospheric temperature situation kept for PTCR ri - Resistance value of PTCR when atmospheric temperature is ii Pi - Power signal of circuit given to computer this duration will depend on the value of resistance. Φ(.) - System software functions which handle sending trigger to circuit and getting output signal from circuit and display the temperature. T - Threshold resistance value for the system software is IK ohms. If the resistance value in Kilo ohms then time difference is high so that accuracy will be more. Q - The output temperature displayed in monitor Where as in the mathematical notation, Based on figure.3, ii a ri a pi a Q (a means proportionate) This equitation means. If the input temperature changes then resistance is changing, If resistance is changing the length of the output pulse changes. So, Output temperature also changes. Fig. 4. Method of computing temperature in computerized thermometer C is High-level computer programming language, it is used for calculating the pulse length given by the circuit and display the temperature and maintain the database in milliseconds with the corresponding temperature used in software. The following algorithm will explain how the software is displaying the temperature. Initially, for the first round the number of millisecond associated with number of centigrade is fed to the computer manually. Based on the first time data software will display the temperature in centigrade. Figure. 4 gives list of steps performed in the C program. Algorithm 1. To get the value of data register. If the value is 0 then display "your circuit is not powered on". 2. To generate the negative pulse to initiate circuit send signal to printer port. 3. Immediately circuit will give output to busy pin, which is in the parallel ports. Note the system time (milliseconds) into any variable. 4. Check the busy signal is low. If it is low then note the system time store into another variable. (Milliseconds). 5. Calculate the time difference between two variables. 6. To display the results into milliseconds. 7. If it is the first time, then observe the temperature also manually and feed into the computer for the future reference. 8. Compare the milliseconds with database, which contains temperature and milliseconds and display correct temperature. ADVANTAGES 1. Without traditional ADC (Analog to digital converter). 2. Very low cost 3. Calculations are in millisecond, so accuracy will be more. 4. Compact circuit (small size). 5. No limitations. 6. Suitable for all computers irrespective of its Hardware architecture PROGRAM #include #include #include #include #include main() { int a=0,b=0; int ins,msl,ms2;long tl,t2,t3; struct timeb t; clrscr0; b=inportb{0x378); if (b=0) printf(*your circuit is not power on"); exit(-1); outportb{0x3 7a,0x0 0); outportb(0x37a,0xff); delay(l); outportb(0x37a,0x00); a=inportb{0x379) ; ftime{&t) ; msl=t.inillitm; tl=t.time; while(a { a=inportb(0x379); } ftime(&t); t2=t.time; ms2=t.millitm; t3=t2-tl; ms=ms2-msl; if((t3)!=0) ms= (1000*t3)+(ms2-msl); else ms=ms2-msl; printf{"\n\n\n millisec difference=%d" ,ms); a=inportb{0x379); printf("\n\n%x",a); getchO ; } We claim: 1. A computerized thermometer for measuring the temperature, where a computer is provided. As shown in Figure. 1 parts of circuit are attached with computer parallel port, 5V DC battery and attached with Positive Temperature Co-efficient Resistance. 2. The computerized thermometer, which calculates temperature method is described in Figure. 4 using Hardware setup described in Figure. 1 3. Substantiated as here in before described before and as illustrated in figure 1,2,3 & 4 of the drawings accompanying the complete specification.

Documents:

625-mas-1999-abstract.pdf

625-mas-1999-claims filed.pdf

625-mas-1999-claims granted.pdf

625-mas-1999-correspondnece-others.pdf

625-mas-1999-correspondnece-po.pdf

625-mas-1999-description(complete)filed.pdf

625-mas-1999-description(complete)granted.pdf

625-mas-1999-drawings.pdf

625-mas-1999-form 1.pdf

625-mas-1999-form 19.pdf