# 0.2 Operational amplifiers and signal conditioning  (Page 4/5)

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The resultant signal should be an 800 mV sine wave with minimal offset.

Using the inverting gain circuit shown in Figure 8, amplify the output of the differential amplifier circuitby an additional factor of ten. This can be done with another op-amp and a 10 k ohm resistor and a 30 k ohm resistor. Theresultant output signal should have a mean of zero and amplitude of ~2.4 V. Adjust the potentiometer to remove any offset.

## Part 7: low-pass filtering

A low pass filter can be used to attenuate high-frequency noise in an analog signal and to minimize the portion of the signal that will be aliased. Later in this lab, youwill see a demonstration of the damaging effects of aliasing.

## 7.1 build an active low-pass filter

• Build the first-order filter shown in Figure 9 with R1 = R2 = 10 k ohm and C2 = 0.1 micro F. First order filters are so-called becausetheir dynamics are modeled by first-order differential equations.
• Connect the output of the circuit to Channel 1 on your DAQ system.
• The filter’s time constant is equal to R2C2. Calculate values for the cut-off frequency and the time constant.

## 7.3 modifying existing vi to measure magnitude ratio

By measuring the magnitude of the input and output of a filter, you can determine the how much the filterattenuates the signal.

• Delete the Amplitude and Frequency constants from the Block Diagram.
• Hold Ctrl as you drag the Tone Measurements icon to make a copy.
• Place a Split Signals icon to the left of the Tone icons.
• Place a Divide function to the right of the Tone icons.
• Create a numeric indicator at the x/y output terminal of the Divide function.
• Rename the numeric indicator Magnitude Ratio. (The Magnitude Ratio represents the output amplitude divided by the inputamplitude.)
• Wire the Block Diagram as shown in Figure 10.
• Save the VI.

## 7.2 testing a filter

We expect that the filter will allow frequencies below the cut-off frequency to "pass", and willattenuate signals at higher frequencies. The Magnitude Ratio will be recorded as the output magnitude divided by the inputmagnitude.

• Connect the signal going into your filter to Channel 0 of module 1 of the SCXI.
• Connect the signal coming out of your filter to Channel 1 of module 1 of the SCXI.
• Input a 1 V sine wave with zero offset into the low-pass filter circuit.
• Starting with a frequency of about 10 Hz, slowly increase the frequency of the input signal. What happens to the outputsignal?
• Increase frequencies to 2 kHz.
• Using the table below, determine the magnitude ratio at several frequencies.

Table 1: Magnitude Ratio Data for First-Order Low-Pass Filter (Active)

 frequency (Hz) Input magnitude (V) Output magnitude (V) Magnitude ratio 10 1V 18 1V 32 1V 58 1V 110 1V 190 1V 340 1V 620 1V 1100 1V 2000 1V
• Using Excel, plot the following two sets of data on a single log-log chart.
• Calculated magnitude ratio vs. frequency.
• Measured magnitude ratio vs. frequency

Do the magnitude ratio and phase difference between the input and output behave as you would expect?

#### Questions & Answers

are nano particles real
yeah
Joseph
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no can't
Lohitha
where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
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da
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Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
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Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
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Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
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Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
how did you get the value of 2000N.What calculations are needed to arrive at it
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