Questions tagged [wheatstone-bridge]
A circuit to measure an unknown resistance.
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INA125 problems
I'm trying to measure a bridge sensor using an INA125 connected to my Arduino and Adafruit ads1115, but the output seems stuck on 5.88V (the power supply is 12V singl supply). Its connected as in the ...
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2answers
961 views
Should we use wheatstone bridges nowadays?
For measuring strain gauges, the Wheatstone bridge is the historical choice.
In a quarter Wheatstone brigde (\$350 \Omega \$ typically (?)), with a high input impedance amplifier, and some bridge ...
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3answers
124 views
Reasons for strain gauge drift
I'm testing a load cell where the result drifts over time.
By weighing it down with a known weight over night, the result crept up by 10% in 18 hours. It's a completely linear increase, with ...
2
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2answers
59 views
How does full wheatstone bridge with strain gauges work?
I have gone through a number of tutorials on Wheatstone bridge and how to use it to sense load using strain gauges. I have also gone through the calculations where one of the resistors of the ...
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1answer
68 views
Why is my amplified strain gauge output so unstable?
I've attached a strain gauge to a bending arm of a robot, and it varies by about 1.5 ohms from 356 to 357.5 ohms. I place this in a whetstone bridge.
The strain gauge is R3. R1, R2, and R4 are all ...
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1answer
73 views
Wheatstone bridge and difference op-amp
I use Wheatstone bridge as a dual voltage divider to feed both inverting and non-inverting inputs of differential op-amp:
Theoretically voltage can be calculated using voltage divider expression: Va =...
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2answers
64 views
Low current strain gauge
I am trying to make a low power device (based of RSL10 bluetooth SoC) that would sample a strain gauge @1kHz and transmit the measurements. The current drawn by the running SoC is about 1.5mA, while ...
2
votes
3answers
90 views
Mathematical help with Wheatstone bridge
This is a homework, so I won't ask for a complete solution, but can anyone tell me how should I approach this?
I've been sitting now for hours without any progress, all that I know is the answer ...
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1answer
51 views
Output Voltage Formula verification of Operational Amplifier circuit
I'm trying to built an op-amp circuit for a PT100 temperature sensor.
I've found the following circuit diagram online (from a polish website):
And I'm trying to find the formula for the output ...
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1answer
58 views
Difference between Proteus results and KCL-deduced formula
I'm designing a small circuit using an op-amp for a temperature sensor (PT100).
I took the design online (see below).
I tried to find out the formula for finding the value Vout as a function of the ...
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0answers
129 views
3-Wires PT100 simple circuit design
I'm new to using PT100 sensors and to electronics in General (my knowledge in electronics starts and stops with Arduino).
However I'd like to design a simple PT100 (3-wires) sensor circuit.
I found a ...
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1answer
156 views
Strain gauge amplifier - so much noise!
I'd like to use atmega328p to read force with strain gauge. I'm using one 1k strain gauge and 3x 1k ohms dummy resistors.
My circuit looks like that:
I'm using DAC to remove offset from bridge.
As ...
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1answer
63 views
Remove bridge offset before ICF amplifier or at FB pin?
I'm making project where I would like to read from stain gauge sensor. It will use only one 1k ohm (or 350 ohm) strain gauge and 3 dummy resistors to complete bridge (1k or 348 ohm). I'd lik to feed ...
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2answers
49 views
Wheatstone Bridge Single-Element Varying
So, this book is saying that when V_B is 10V, R is 100ohms, and delta R is 0.1 ohms, The linearity error is 2.5mV - 2.49875mV = 0.00125mV.
I don't quite understand where 2.5mV came from.
If I use ...
0
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1answer
63 views
ADS1115 differential output
I have the output of a wheatstone bridge going into an ADS1115.
I am exciting the bridge with a 24VDC supply and the ADS1115 with 3.3VDC through a Raspberry Pi.
The issue I am having is that when I ...
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1answer
129 views
Wheatstone Bridge - strain gauge sensor
I'm trying to optimize a Wheatstone bridge with a strain gauge sensor and I'm considering all possible wire resistances. The circuit is shown in the following figure:
I don't understand the comment ...
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0answers
102 views
RTD wheatstone resistance question
I have a question im currently working through, its as follows
'A platinum resistance thermometer has a resistance of 100 Ω and a temperature coefficient of resistance of 4x10-3 °C-1. Given that a 10 ...
2
votes
2answers
81 views
How are the terminal voltages regulated for this Wheatstone bridge?
At page 34 from this datasheet the following circuit shows a single-ended amplifier used to produce single-ended gain:
As you see the excitation voltage terminals is sensed by Kelvin connection ...
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1answer
65 views
DIY water tank gauge using analogue ammeter - linearity
A follow up question to my previous on building a DIY water gauge DIY water tank gauge using analogue ammeter.
I have scrabbled together a "Euro type" sender (10 Ω empty - 180 Ω full) and ...
4
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3answers
564 views
What is the value of the current (i) and what is the right way to do it? [duplicate]
What exactly went wrong with the below method?
Here, in the same circuit I am getting a different value for the current in the mid wire only by rearranging the circuit.
I was trying to solve this ...
0
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1answer
148 views
What's wrong with this Wheatstone bridge?
I was trying to solve this unbalanced Wheatstone bridge and found that the current $i$ in the mid wire is 9A .This result was achieved by using node voltage method.
Then I rearranged the same circuit ...
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3answers
93 views
What can be the reason for the extra connections from this Wheatstone bridge to the amplifier?
This industrial amplifier is used for force transducers and here is the wiring diagram for the 6 wire transducers:
¨
And below is the terminals for the amplifier:
It seems 1 and 4 terminals are the ...
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0answers
66 views
Wheatstone gauge factor calculation?WII load cell
Currently working with the WIIFIT or WIbalance load cell. For some reason everybody wants to work with these load cell. However, there are no actual datasheet of the load cell used in the device. ...
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1answer
42 views
Is this voltage rating relative to ground or differential?
A transducer has this datasheet.
What is meant by Bu,g?
The amplifier I use applies +10V and -10V to excitation terminals so the difference between the terminals will be 20V and the excitation ...
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3answers
306 views
What does this resistor do in this RTD wheatstone bridge?
The question is in bold at the bottom, the following is background.
I am going to measure air flow with a hot wire anemometer using the FS7 sensor from Innovative Sensor Technology (IST). They ...
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1answer
1k views
How does temperature compensation work for strain gauge in wheatstone bridge
Wheatstone bridge is used for temperature compensation for strain gauges
If 2 strain gauges are connected like this figure. Due to temperature variation; the resistance Rg will change in the same way....
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4answers
2k views
How does 3-wire RTD or resistance measurement works in bridge of wheatstone?
I cannot understand how 3-wire measurement will improve the resistance measurement.
They say that IF lead resistance \$ R_L \$ is the same, it will compensate. How can this happen?
If bridge is ...
0
votes
1answer
781 views
Thevenin resistance for bridge circuit
So I've been at this question for a few hours now and i can't seem to get the final answer for a). I know how to find the the resistance of a basic Wheatstone bridge, but i don't know how to find the ...
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0answers
404 views
How to connect bathroom scale (arduino+hx711+spark load connector)
Im a new user in the electronic world. I tried to hack my bathroom weight scale but no success. There is a great tutorial which I followed:
https://www.youtube.com/watch?v=iywsJB-T-mU
my parts:
...
0
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1answer
216 views
Basic question on temperature compensation of resistive bridge circuits
Many force transducers like this one are made up of Wheatstone bridges and they have sensitivity which relates the force/stimulus change to the voltage change. This small voltage change then is ...
0
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1answer
68 views
why the 3 stage differential opamp not worked [closed]
i did the following in simulation its work.
but in practically, i cannot able to get a amplified output.
i use ic741 as a op-amp 5v input for opamp and bridge power supply... i get always 1.77v in my ...
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2answers
765 views
Strange Behaviour Using LM358 Op-Amp as Wheatstone Bridge Difference Ampliflier
I've been working on building a circuit which uses a wheatstone bridge to find the value of a resistance temperature sensor (Danfoss AKS 21) and then passes that to a differential amplifier the output ...
0
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1answer
110 views
How to explain why equivalent resistance between two points in this network is dependent on specific resistance?
The original network is an square network with two diagonals as you can see here there is no intersection between the diagonals.:
The question is what is the equivalent resistance between points A ...
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1answer
419 views
A way to 'digitalize' a wheatstone bridge
I am currently using a Wheatstone bridge to determine the resistance of a NTC thermistor and feed the difference to the setpoint (analog potentiometer) as the error signal to a PID controller, giving ...
0
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1answer
293 views
Wheatstone Bridge imbalance voltage calculation
So I have this simple force measure circuit which consists of a strain gauge SG1 and the amplifier with the Wheatstone bridge, the variable resistor RV1 is set to 200Ohms. If the strain gauge is ...
2
votes
1answer
293 views
Compensating for offset voltage in bridge measurement before instrumentation amplifier
I'm using an instrumentation amplifier (INA118) to measure the signal from a full bridge strain gauge (tension only, all 4 resistive elements are strain gauges, slow changing (DC) signal). I'm using a ...
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1answer
72 views
What type of sensor has diamond pinout like shown? Resistive bridge? Wheatstone?
I have worked with basic resistive sensors before, but I have never seen a pinout like this one and I'm not sure how the voltages work for these pins. I was told it may be a resistive bridge, but it ...
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2answers
279 views
Differential equation from a Wheatstone bridge with Inductor
I've been given the following circuit and been asked to give the differential equation showing the relationship between \$u_e(t)\$ and \$u_a(t)\$
The differential equation should be in the form
$$\...
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4answers
1k views
Finding equivalent resistance of a resistor network
In the circuit below, all of the resistors are 15 Ohms. I am trying to find the equivalent resistance between A and B.
Can we argue that since RAD/RDC = RAO/ROC that AODC is a wheatstone bridge and ...
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2answers
5k views
How to calculate maximum gain that can be achieved by an op amp?
I am designing a differential amplifier for a Wheatstone bridge which have small voltage variations like 0uV to 20uV. so need to design an instrumentation amplifier. I do not know how to find the ...
3
votes
1answer
3k views
LM324 op-amp wheatstone bridge amplifier formula
I'm planning to use an LM324 opamp as a signal amplifier for a cell load (strain gauge in a Wheatstone bridge). This particular application is shown in the datasheet (see image). It shows the ...
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1answer
260 views
AD8422 LTSpice simulation
I am trying to simulate a wheastone bridge amplified with an AD8422. In principle, with a Rg of 500 ohm, it should give me a gain of 40, according to $$ G = 1 + 19.8k\Omega/R_G $$ but instead I get a ...
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3answers
932 views
How do I use this Strain Gauge sensor?
The load cells here: http://www.cnloadcell.com/mlc700-postal-scale-load-cell and here: http://www.cnloadcell.com/mlc714n-personal-scale-weight-sensor have 4 wires (red, white, black, green).
The ...
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2answers
1k views
how to connect strain gauge to HX711 module
I need get strain gauge reading to Arduino. so far i have found load cell Wheatstone configuration circuit here 3rd answer. I need to know if i connect a strain gauge to one +Active resistance, and ...
4
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1answer
410 views
Difficulties reverse engineering a digital bathroom scale
I apologize if this has been discussed elsewhere and for the length of the post. This is a group project and we plan to take the weight value from the scale and send it via a WiFi connection to ...
2
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2answers
741 views
Alternative Wheatstone bridge for thermistor - Interpretation needed
I have a problem understanding the following Wheatstone bridge circuit. It originates from a temperature controller, the voltage V_out is supplied to a PID regulator and hence can be seen as an error ...
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1answer
1k views
Why can't a Wheatstone bridge measure resistance of very high value?
The answer is from google but I don't get it. Can someone explain in more simple way?
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1answer
382 views
Backwards proof for balanced Wheatstone bridge
simulate this circuit – Schematic created using CircuitLab
We know that in this Wheatstone bridge if,
\$\bf{I_3 = 0}\$, it can be derived that \$\bf{\frac{R_1}{R_5}=\frac{R_2}{R_4}}\$ . But ...
2
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4answers
2k views
Strategy to balance a Wheatstone bridge for strain measurement
The purpose of my project is to build a sufficiently accurate "Strain indicator" based on the use of a Wheatstone bridge using an Arduino. Currently I am using a HX711 as load cell amplifier which is ...
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2answers
701 views
Help needed on wheatstone bridge problem
My circuits 1 professor gave us some practice problems for an upcoming exam, and I'm not sure that I know how to do this one.
My approach was to apply the circuit divider formula for the left and ...
