Voltmeter Using 8051(Range 0-15V)

A voltmeter finds its importance wherever voltage is to be measured. A voltmeter is an instrument used for measuring the electrical potential difference between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit. General purpose analog voltmeters may have an accuracy of a few per cent of full scale, and are used with voltages from a fraction of a volt to several thousand volts.  Digital voltmeters give a numerical display of voltage by use of analog to digital converter. Digital meters can be made with high accuracy, typically better than 1%. Specially calibrated test instruments have higher accuracies, with laboratory instruments capable of measuring to accuracies of a few parts per million. Meters  using amplifiers can measure tiny voltages of micro‐volts or less. Digital voltmeters  (DVMs) are usually designed around a special type of analog‐to‐digital converter called  an integrating converter. Voltmeter accuracy is affected by many factors, including  temperature and supply voltage variations. To ensure that a digital voltmeter's reading is  within the manufacturer's specified tolerances, they should be periodically calibrated.  Digital voltmeters necessarily have input amplifiers, and, like vacuum tube voltmeters,  generally have a constant input resistance of 10 mega‐ohms regardless of set  measurement range.  This project aims at building a Digital Voltmeter using an 8051 microcontroller. All the  data accessed and processed by the microcontroller is the digital data. And thus, the  usage of an analog‐to‐digital converter finds its necessity here. A standard analog‐to‐ digital converter ADC0804 is used in the current project. The input voltage (which is the  analog input) is restricted to be in the range of 0‐15V. The processed data in the 8051 is  used to drive a display output on a LCD display unit. The display is in the form of digits  and is accurate to a value of one decimal. The input voltage is desired to be that of a DC  voltage for steady observations of the voltage value on the LCD panel. Rather, if an AC  input voltage is given at the input terminals, the output varies indefinitely as is the  nature of AC voltage. Thus, the instantaneous value of the AC voltage is not steadily  shown on the LCD panel.

Component Used:

Following is the entire set of the components used to build the Digital Voltmeter:

1. Microcontroller, AT89S51

2. Analog‐to‐Digital Converter, ADC0804

3. 16x2 LCD

4. Oscillator circuit for the microcontroller

4.1 12MHz Crystal Capacitor

4.2 33pF Capacitors

5. Voltage divider circuit/ Input terminals

5.1 200k, 100k, 10k Resistors

5.2 100nF, 150pF, 4.7uF Capacitor

6. ADC Clock Circuit

7. 40 pin,20 Dip

8. 16, 8 Pin connectors

9. 7805 Voltage Regulator IC

10. ON/OFF Switch

11. 9V Battery
*** For Program and hex fine, contact to Nazish Shahab.
Price in Jaipur Rs-2000
Price in other cities Rs-2500
Designed By- Nazish Shahab
Near JNU Main Campus
Jagatpura, Jaipur, 302025
Contact No: 7665409048/ 7877698634