The previous voltage divider design is suitable for only measurement of higher values of resistance (50 Ohm to 1 MOhm) to measure very small value resistance we have built this circuit, it consists of constant current source of 100mAmp. Measuring voltage drop across a resistor having constant current gives us resistance value (R = V / I).
Calculations
V = I x R
R = V / I Continue reading Measurement of Low value resistance (0.1 to 50 Ohm)
Tag Archives: measurement
Arduino Resistance Measurement
Definition
The electrical resistance of an electrical conductor is a measure of the difficulty to pass an electric current through that conductor. It is measured in Ohms.
What you will learn?
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How to use arduino to measure resistance?
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How to apply simple ohms law?
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What are the different methods of resistance measurement?
AC Current Measurement using ACS712
The ACS712 measures current in two directions. It means that if we sample fast enough and long enough, we sure to find the peak in one direction and the peak in another direction as the ACS712 have 5 μs output rise time in response to step input current. We are measuring AC current of 50Hz i.e. 20mSec per cycle and we get around 4000 Samples in one cycle.
With both peaks known, it is a matter of knowing the shape of the waveform to calculate the current. In the case of line or mains power, we know that waveform to be a SINE wave. Knowing that allows us to apply a basic electronic formula to yield a decent result.
RMS Current = root(2) * Peek Current Continue reading AC Current Measurement using ACS712
DC Current Measurement using Shunt Resistor
Designing of Digital Ammeter is basically a process of converting a voltmeter into Ammeter. We know that V=I x R. From this we can say that Voltage drop across resistor (shunt) is directly proportional to the current (V = I). In ammeter this resistance is called Shunt. Shunt resistance have very small value and it will not affect the load voltage. Most commonly 75mV shunts are available in market. Or you can use low value resistance. Continue reading DC Current Measurement using Shunt Resistor
DC Current Measurement using ASC712-05A
Definition
An electric current is a flow of electric charge. In electric circuits this charge is often carried by moving electrons in a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in plasma. It is measured in Ampere. Continue reading DC Current Measurement using ASC712-05A