Simple Digital Voltmeter Circuit with PCB using ICL7107

 Power Supply 9v/12v

Resistor 47.5k ohm

Rotary potentiometer (generic)

 Probe or wire 

Resistor 10k ohm

Capacitor 100pF

Resistor 22.1k ohm

555 Timers

Capacitor 100 nF

8 pin IC socket

Male Header 40 Position 1 Row (0.1")

Linear Regulator (7805)

40 pin IC socket

IC7107

Terminal Block - 2-pin

PCB 

SparkFun 7-Segment Serial Display - Red

Resistor 120K ohm

1N4148 – General Purpose Fast Switching

 Capacitor 220nF

Resistor 1k ohm

Capacitor 47nF

Capacitor 10 µF

<p >In this project we have a tendency to design a circuit to build an electronic voltmeter while not making use of any microcontroller. Here we have a tendency to employ a very moderate IC for voltage activity, particularly ICL7107/CS7107. Making use of ICL7107, we are able to build a correct and very affordable digital voltage measurement meter. ICL7107 may be a 3.5 digit analog to a digital device (ADC) that consumes extremely low power. The IC has an internal circuit for driving four 7-segment displays to show the measured voltage. It additionally encompasses a clock circuit and a reference voltage supply.</p><figure><img src=https://projects.arduinocontent.cc/84a5c6b0-7252-4773-a3ee-43e539cdeeb7.png /><figcaption>Figure 1: Simple digital voltmeter Circuit </figcaption></figure><h3 >Required Components</h3><ul ><li >IC7107                   </li></ul><ul ><li >LM555</li></ul><ul ><li ><span >PCB (</span><a href="http://Wellpcb.com">Wellpcb.com</a><span >)</span></li></ul><ul ><li >LM7805</li></ul><ul ><li >7 segment LED display (Quantity: 4)</li></ul><ul ><li >Terminal Block 2 pin (2)</li></ul><ul ><li >47k </li></ul><ul ><li >1k (5)</li></ul><ul ><li >22k </li></ul><ul ><li >10K</li></ul><ul ><li >120K</li></ul><ul ><li >Pot 5K </li></ul><ul ><li >100nF (3)</li></ul><ul ><li >10uF (2)</li></ul><ul ><li >100pF</li></ul><ul ><li >220nF</li></ul><ul ><li >47nF</li></ul><ul ><li >Power Supply 9v/12v</li></ul><ul ><li >Berg sticks (2)</li></ul><ul ><li >40 pin IC base </li></ul><ul ><li >8 pin IC base</li></ul><ul ><li >Probe or wire</li></ul><ul ><li >1N4148 diode (2)</li></ul><h3 >Circuit Diagram and Working Explanation</h3><p >The working of this electronic voltmeter circuit is extremely straightforward. ADC within the IC is a desegregation device or twin-kind analog to digital device. Internal ADC of this IC reads the voltage to be measured and compares it with an indoor reference voltage and converts that into the digital equivalent. Then this digital equivalent is decoded for the 7-segment displays by a driver circuit within ICL7107 and so shown over four 7-segment diode displays. </p><figure><img src=https://projects.arduinocontent.cc/47fa8516-4de0-47a6-b0b5-577ee106b113.png /><figcaption>  Figure 2 Circuit diagram</figcaption></figure><p >Here electrical device R1 and electrical capacitor C1 area units won’t set the frequency of the internal clock of ICL7107. Electrical capacitor C2 filters the fluctuations in internal reference voltage and provides stable reading on 7-segment displays. R5 is to blame for dominant the variations of the meter. (R5=1K for 0-20V vary and 10K for 0-200V range). RV1 could be a potentiometer which can be used for calibrating the voltage of meter or may set the reference voltage for internal ADC.</p><p >This circuit includes four common anode 7-segment displays with a negative voltage indicator. This circuit ought to be operated at 5V voltage offer, that’s why we've got used a 7805 transformer IC to provide 5v to the circuit still as for preventing the injury of ICL7107.</p><p ><strong >Negative Voltage Supply:</strong><span > Here we have to be compelled to offer negative power to PIN 26 of the ICL7107. The 555IC timer IC is designed here as ASTABLE multi-vibrator. The electrical device here may be modified but the choice ought to pursue for optimum negative voltage. If hand-picked capacitance doesn't suit well, then we have a tendency not to get the most negative voltage at the output. Here we've used 100nF and 10uF.</span></p><figure><img src=https://projects.arduinocontent.cc/000c926e-a4c0-4a90-940b-18b2853e0713.png /><figcaption>Figure 3 Block diagram of the circuit implementation</figcaption></figure><h3 >PCB Design using Wellpcb</h3><p >They recently launched their part sourcing service where they also have available stock of electronic parts and users can order their needed parts beside the PCB.</p><figure><img src=https://projects.arduinocontent.cc/0d00b263-d8f0-4a14-af8e-d0585e784103.png /><figcaption>Figure 4 Top layer PCB layout</figcaption></figure><p ></p><figure><img src=https://projects.arduinocontent.cc/06278266-d814-4850-91a5-c05dd29fa7be.png /><figcaption>Figure 5 Photo view of the voltmeter</figcaption></figure><h3 >Calculating and Ordering Samples Online</h3><p >After finishing the look of the PCB, you'll be able to click and order it online. You can try the prototype facility provided by the company. Here you'll be able to read your PCB in Gerber Viewer or transfer Gerber files of your PCB. Also you'll be able to choose the quantity of PCBs you would like to order, what percentage copper layers you wish, the PCB thickness, copper weight, etc. You can get an instant quote by using the link below:</p><p ><a href="http://www.wellpcb.com/pcb-quote">http://www.wellpcb.com/pcb-quote</a></p><figure><img src=https://projects.arduinocontent.cc/71e06521-4e09-4b42-ac9e-a9eff63b93f0.png /><figcaption>Figure 6</figcaption></figure><p >Below are the images after the soldering of the components on the PCB:</p><figure><img src=https://projects.arduinocontent.cc/f8ee1e48-45c9-4810-b094-5523c846f0eb.png /><figcaption> </figcaption></figure><p ></p>

Simple Digital Voltmeter Circuit with PCB using ICL7107

Here I built a simple digital voltmeter circuit with a PCB using ICL7107.