Tsukure Mad Labs Digital Voltmeter

In this project we are going to build a Digital Voltmeter without using any microcontroller. Here we are using a very popular IC for voltage measurement namely ICL7107/CS7107. Using ICL7107, we can build accurate and very low cost voltmeter. ICL7107 is a 3.5 digit analog to digital converter (ADC) which consumes very low power. The IC has internal circuit for driving four seven segment display to display the measured voltage. It also has a clock circuit and a reference voltage source.

Voltmeter is very useful device and comes very handy many times, that’s why we have built this Digital Voltmeter on PCB so that it can be used anywhere easily.

Let's Get Started!

Below you will find a list of bits to gather before hand, followed by a detailed schematic. Using a breadboard lay out the components and connect them together as shown. Alternatively you can purchase this module from our shop and simply solder the components in the places indicated on the quality assured printed circuit boards provided.

What You Need...

1 101 (100pF / 0.1nF) Capacitor (Ceramic)
3 104 (100nF / 0.1uF) Capacitor (Ceramic)
1 224 (220nF / 0.22uF) Capacitor (Ceramic)
1 473 (47nF / 0.047uF) Capacitor (Ceramic)
2 10uF Capacitor (Polarized)
2 PCB Mount 2-Pin Screw Terminal Block Connector (Other)
2 1N4148 Diode
4 7-Segment Display (Red) - Single Display
1 555 Timer Integrated Circuit (IC)
1 ICL7107 Integrated Circuit (IC)
1 5mm Red (Diffused) LED
1 12V 2A DC Power Supply
1 10K
[ Brown, Black, Black, Red ]
Resistor (0.25 Watt)
1 120K
[ Brown, Red, Black, Orange ]
Resistor (0.25 Watt)
5 1K
[ Brown, Black, Black, Brown ]
Resistor (0.25 Watt)
1 22K
[ Red, Red, Black, Red ]
Resistor (0.25 Watt)
1 47K
[ Yellow, Violet, Black, Red ]
Resistor (0.25 Watt)
1 50K (503) Resistor (Trim Potentiometer)
1 LM7805 Voltage Regulator

NB: Any resistor colour codes specified relate to 5 band resistor codes, the 5th band has not been shown intentionally. The 5th band indicates the resistor tolerence, we use only the highest tolerence resistors in our products.

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Just An Idea!

This project is currently just an idea, a prototype! This is how we begin our journey of discovery and welcome you to join us.

Why not have a go at making this idea into a working project.

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