# Complete Guide How To Strain Meter Circuit Design Using IC741

We will use Strain Meter Circuit IC741  because we can easily perform various operations with this strainmeter. For example, it easily helps in measuring the volume, distance, compression, distortion, and other measures of any substance or material.

With this meter, we can easily determine the state of any substance or materials without any mathematical calculation. Also with the help of this meter we know the rotation value of motors, shafts, and many other rotating instruments, the number of rotations per time, how many rpm everything is going through this meter.

Another important aspect of this is the tendency of the inside of a substance or material to twist or break and how much pressure is working against it and how it determines the probability of the substance to rot.

Since using this meter we can know about these states of matter without any mathematical calculation. So we can use this strain meter circuit.

## ≡ Component and working details:

01. IC: In this circuit we use are three different types of IC. There are IC1-7805, IC2-7660, and IC3-741 IC in this here. The IC1-7805 Voltage regulator is a type of self-contained fixed linear voltage regulator integrated circuit.

There are 3 pins in this IC they are pin1-Input, pin2-Common, pin3-Output. This is a 5 volt IC with a 5 volt supply in the circuit. IC2-7660 is a converter ic. This Ic converting capacitor voltage.

This is 8 pin in this ic. There are pin1 is an (NC) pin this meaning normally close, pin2 is supplied positive capacitor voltage (cap+), pin3 is the ground connection, pin4 is supplied negative capacitor voltage (cap-), pin5 is the output pin, pin8 is (+V) positive voltage.

IC3-741 is an op-amp IC. This IC has 8 pins, There are pin1 is offset null, pin2 is Inverting Input, pin3 is Non-Inverting Input, pin4 is negative voltage supply, pin6 is the output pin, pin7 is the positive voltage pin and pin8 is normally close (NC) pin

02. Resistor: Resistors are used in virtually all electronic circuits and many electrical ones. Resistors, as their name, indicates resist the flow of electricity. In this circuit, we use the 7th resistor. There are R1=120ohm, R2=120ohm, R3=120ohm, R4=10k, R5=220k, R6=5.6k, R7=22k resistor.

03. Capacitor: A capacitor is a device that stores electrical energy in an electric field. The job of a capacitor is to hold a charge. This ability to hold a charge called capacitance. In this circuit, we use the 4th different type of capacitor. There are C1=220n, It is a nonpolarity capacitor. And other’s capacitor in this here.

There are C2=1mu-16v, C3=10mu-16v, C4=10mu-16v. This is a polarity capacitor. There are C2, C3, C4 polarity capacitor. Because this capacitor indicates a positive & negative pin. So this is a polarity capacitor and if not indicate positive & negative pin then this capacitor is a non-polarity capacitor.

04. Variable Resistor: A variable resistor is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals used, one end and the wiper, it acts as a variable resistor or rheostat. In this circuit, we use 2 more than a variable resistor. There are VR1 and VR2 variable resistor.

05. Zener Diode: A Zener diode is a special type of diode designed to reliably allow current to flow “backward” when a certain set reverse voltage, known as the Zener voltage.

06. Switch: on-off switch – a hinged switch that can assume either of two positions.

## ≡ How to work this circuit:

Strain meters The work of this circuit is much easier. When there is no interruption in the strain gauge in the circuit, VR1 and VR2 are ready to give zero readings on the multimeter through them. This zero voltage can replaced by any other voltage.

For example 1.5 volts, but in the case of circuit, there is no need to supply 0 voltage. If the meter reading increases then the length of the strain gauge increases and if the meter reading decreases then the length of the strain gauge decreases.

This circuit is able to respond to different levels. The sensitivity of the op-amp IC can adjust VR2. The supply voltages IC5 and IC2 +5 volts and -5 volts, respectively, ensure stable readings on the meter and prepare the output from the op-amp Whitestone Bridge. This is how this meter works.

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#### MD Omar Faruk Team Member Mechatronics lab

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