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Questions tagged [wheatstone-bridge]

A circuit to measure an unknown resistance.

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2answers
50 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
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3answers
83 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
44 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
50 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
43 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
134 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
49 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
32 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 ...
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1answer
42 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
67 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
56 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 ...
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2answers
69 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
53 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 ...
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3answers
514 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 ...
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1answer
127 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
85 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
49 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
37 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
244 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
977 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
1k 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 ...
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1answer
612 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
333 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: ...
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1answer
172 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 ...
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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
577 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 ...
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1answer
104 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
330 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 ...
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1answer
273 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
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1answer
258 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
69 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
258 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
762 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
4k 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
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1answer
2k 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
230 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
758 views

How do I use this Strain Gauge? (4 wire)

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
381 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 ...
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2answers
625 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
333 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 ...
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3answers
1k 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
583 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 ...
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0answers
296 views

Output voltage approximation in Wheatstone bridge

When I calculate the potential difference in the above circuit, I find: v1 = Ug*(ΔR+R)/(2R+ΔR) v2 = Ug*(R)/(2R+ΔR) Uo = ΔU = v1-v2 ΔU = Ug*[ΔR/(2R+ΔR)] But it is always approximated to: ΔU = Ug*...
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0answers
318 views

Load cell circuit does not work on circuit simulator

I want to simulate a load cell interfacing with AD620 for amplification. - My load cell is 40 Kg max with 2mV/V sensitivity and 10 V excitation voltage with input resistance of 405 ohm and output ...
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1answer
957 views

INA125P Strain gauge amplification problem

I'm using the INA125P to amplify the strain of a 350 ohm strain gauge in a self-built Wheatstone bridge circuit for measurement. I'm testing using a 351 ohm resistor to mimick a strain gauge under ...
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1answer
101 views

Negative differential to instrumentation amplifier causing problems

I am using a pair of strain gauges to make a weight scale. The strain gauges are the three-wire type that you can by on Amazon or Sparkfun. The strain gauges form a full wheatstone bridge, whose ...
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2answers
157 views

Hook up a load cell with High Level Amplied Output (only input+ input- output+) to load cell amplifer

I have been successfully hooking up load cells (e.g., TAS606, red = E+, green = O+, black = E-, and white = O-) and load sensors (with help from a load cell contaminator ) to load cell amplifer (e.g., ...
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2answers
696 views

resistor value in wheatstone bridge

I have a resistance based sensor which gives the resistance change when the strain/force is applied. How to measure the unknown resistance change using the Wheatstone bridge circuit.? I mean what are ...