Questions tagged [wheatstone-bridge]
A circuit to measure an unknown resistance.
173
questions
0
votes
2
answers
80
views
Am I overloading my circuit?
I'm using op-amps as schmitt trigger and with the resistors in the wheatstone bridge I am trying to control the flow of current in the load. When the load resistance is not connect between the outputs ...
3
votes
5
answers
377
views
Instrumentation amp giving only positive output (with + and - power supplies)
I'm using an instrumentation amp for a bridge circuit for strain gauges. However, the output range is always positive (the lowest value I can get is zero).
The amp I use is AD620. For power supply I ...
- 31
2
votes
0
answers
35
views
Ratiometric AD conversion with high excitation voltage
Still working on a Wheatstone bridge sensor (a load cell); for reasons unknown it insists to be excited with at least 8V (manufacturer gave no assistance, simply state 10V as nominal excitation)
...
- 7,701
-1
votes
3
answers
59
views
Wheatstone bridge
I need help with solving the following Wheatstone bridge circuit.
I don't know the value of the resistances nor the capacitor.
Where or how do I get started to calculate them?
The variable resistance ...
1
vote
1
answer
70
views
Is it possible to connect a Vin to a ref of an instrumentation amplifier?
I have a circuit in which I need an instrumentation amplifier (INA128 (datasheet)) to be connected correctly for it to work. I don't know if it needs another resistance or if the input needs to be ...
0
votes
1
answer
34
views
Can I drive a bridge sensing circuit with a voltage reference?
On the specification sheet there is this application circuit where the sensing bridge circuit is driven by the same voltage reference IC that sets the voltage reference (REFP) of the ADC.
I remembered ...
- 1,310
2
votes
2
answers
164
views
How to improve HX711 to feed two or more load cells in parallel?
HX711 datasheet
Load cells I'm using
I have typical load cells and want to connect them in parallel directly to the HX711 "A" section of the amplifier.
The load cells have an input ...
0
votes
2
answers
106
views
How can I calculate the values of the four resistors in a Wheatstone bridge?
I measured black-red = 400ohm, green-white = 350ohm in a 5kg loadcell.
How can I calculate the resistor values?
1
vote
1
answer
164
views
How to read four load cells with a single ADC input?
I am currently using strain gauge based load cells and want to weigh 1-5kg granular products on whatever container with 4loadcells beneath. I encountered a problem with connecting load cells in a ...
0
votes
1
answer
48
views
how to calculate the output voltage of specific circuit using superposition law
Hi, How to calculate the output voltage of the circuit is shown below. Using the superposition principle is the best or the one that you recommend. I'm using strain gauges based on the Wheatstone ...
3
votes
1
answer
77
views
How does temperature compensation work for pellistors in Wheatstone bridge?
Pellistors are used to detect combustible gases. Basically, the gas is burned inside the pellistor and the heat released will change the resistance of the detection element. The concentration of the ...
- 57
3
votes
2
answers
142
views
Is there an affordable way to balance a bridge without using expensive resistors?
I have a full and balanced bridge circuit with four through-hole \$ 350 \,\Omega \$ resistors and an instrumentation amplifier AD8293G80 that has a gain of 80. Both the bridge and the amplifier are ...
- 1,310
3
votes
2
answers
524
views
LM358 Differential Two Stage Amplifier Misbehaving (unanticipated output voltages)
Hello all and thank you in advance for taking a look at my problem.
I have made a circuit which takes a differential voltage from a Wheatstone bridge (pressure transducer) and converts to an analog ...
- 51
0
votes
2
answers
54
views
Switching the GND of a Wheatstone bridge using NPN
I am trying to turn on and off the power supply to this bridge by using a micro controller.
Can I use the following switch using an NPN ?
Edit:
A switch using a MOSFET - a better option?
2
votes
0
answers
61
views
RTDs: Resistive Divider or Wheatstone bridge
I've inherited a PCB design in which the circuit for reading a 1k 2-wire RTD sensor is a simple resistive divider. The R_rtd is the pulldown part of the divider. The voltage of the divider is read ...
- 29
2
votes
1
answer
57
views
How to make an accurate strain gauge conditioner
I need to measure tensile strains between 0 and 0.01%, with an accuracy between 1 to 10% within that range.
It seems like all systems that read strain gauges rely on a Wheatstone bridge to amplify ...
- 10.5k
0
votes
2
answers
123
views
Why I am I unable to turn on a load when Wheatstone bridge is connected in series with the load
I am trying to switch on a load by using a Wheatstone bridge and planning to provide the differential voltage to the transistor.
Before doing that, I am trying to use two batteries (second one ...
- 123
0
votes
1
answer
86
views
How do you get a Vout of 2.29 in the simulation with a differential opamp and a wheatstone bridge? [closed]
I made a circuit to read the resistance of a PT-1000 (a platinum RTD [Resistance Temperature Detector] of 1 kΩ at 0°C) and I know I messed something up with the linearity; whatever I try, I can not ...
- 13
0
votes
4
answers
287
views
Use Wheatstone bridge to measure unknown resistance
I have a question about using Wheatstone bridge to measure unknown resistance in practice. It is often stated that if there are one unknown resistor, two known resistors and one variable resistor, ...
- 115
0
votes
0
answers
57
views
Proper grounding of a half open measurement bridge with zeroing variable resistor
I am designing a circuit to read a differential pressure sensor.
The manufacturer gives the following diagram of the half-open measurement bridge:
My understanding is that I am designing a circuit to ...
12
votes
3
answers
1k
views
Need help understanding schematics in LT1019 datasheet
We are currently using AD7795 to get ratiometric reading of 4 load cells. It works, but the chip stocks are rather volatile. So, I am thinking on using much cheaper and easier to come by MCP3424/...
- 10.7k
10
votes
4
answers
3k
views
For this Art of Electronics circuit, why aren't the transistors specified? And what transistors do I use?
If I were going to EE school, then there would be a lot of knowledge transferred just by going through all of the usual things -- labs, homework, exams, etc. In teaching myself, it's so hard when they ...
- 1,999
0
votes
1
answer
69
views
How can I show that there is no current over resistor
I made a contest question regarding find the entire current provide from voltage source 45V connected between a-c terminals. Follow the picture below:
Original circuit
My resolution
I can made it ...
- 91
3
votes
0
answers
80
views
Wheatstone bridge with 3 op amps breadboard help
I have a wheatstone bridge like the following:
I then want to connect it to a couple of op-amps:
I tried doing it like this:
Op-amp pinout:
However, I can't seem to get it to work. Have i ...
- 161
0
votes
1
answer
92
views
Why is the Wheatstone bridge configuration almost always used for sensors over a simple voltage divider? [duplicate]
Everywhere it seems to be taken for granted that a Wheatstone bridge is more precise, accurate etc. I don't see why it would be any better than a voltage divider if I am directly measuring the voltage ...
0
votes
1
answer
248
views
How to choose a resistor value for Wheatstone bridge such that it is a balanced circuit?
I have a 3V sine wave input and I want to measure resistor precisely from 1 ohm to 40ohm. I have tried using Arduino to measure the resistor using voltage divider but it became obvious that I will not ...
- 199
0
votes
2
answers
103
views
(Almost) Wheatstone bridge
I have this wheatstone bridge:
Rmeasure is the impedance of my voltmeter between A and B. My goal is to have the equation of R1/R2. Because Umeasure changes if \$R_2\$ or \$R_1\$ changes.
the values ...
- 51
2
votes
1
answer
77
views
Respiratory rate monitor
I have this project to build an instrumentation system to measure the respiratory rate.
We decided to use a thermistor to measure the variation on the temperature of the air inhaled and exhaled. To ...
- 47
0
votes
0
answers
36
views
What are the trade-offs between different values of resistance for a wheatstone bridge?
I have a loadcell with a bridge resistance of 10k and I've asked the manufacturer for a new design with RTDs and a slight mechanical change, and as a consequence, the manufacturer's proposed new ...
- 1,042
2
votes
1
answer
160
views
Why increasing bridge ratio improve efficiency?
From The Bonded Electrical Resistance Strain Gage by Murray & Miller where it says:
For operation with a single gage, and under some conditions with two
gauges, the efficiency can be improved by ...
- 1,310
3
votes
2
answers
89
views
Wheatstone bridge to create offset
While comparing schematics of two old analog oscilloscopes (Tektronix 475 and Goldstar 9020,) I was expecting many differences to get better frequency response since the first is a 250MHz and the ...
- 2,577
0
votes
1
answer
273
views
Wheatstone bridge: Modifications for different temperature sensor resistance
I am trying to build a Wheatstone circuit to detect temperature changes of a low resistance (about 10 ohm) wire.
For a first try I would like to use a circuit proposed in this Maxim Application Note ...
- 3
0
votes
2
answers
100
views
Lead resistance of 3 wire RTD100
I am using a three wire RTD100 as a temperature sensor.
I know the advantage of the 3 wire RTD100 is that it gives accurate temperature output by canceling the lead resistance. First the resistance ...
- 187
1
vote
1
answer
116
views
How to fit this schematic into my circuit
I am trying to learn how to put schematics onto a breadboard and currently I have this wheatstone bridge used for measuring the voltage change when my R2 resistor is affected by temperature.
Now I ...
- 161
0
votes
1
answer
264
views
How to determine if a load cell is quarter-bridge, half-bridge or full-bridge?
Im looking to purchase 4 disk type load cells for weighing applications but it doesn't mention what configuration it is in (quarter bridge, half bridge etc.) Is it safe to assume 2 wire load cells = ...
- 115
1
vote
1
answer
233
views
Why are two pairs of a wheatstone bridge of opposite direction?
I wonder why are, e.g. when using a wheatstone bridge in combination with strain gauges, two of these SGs do have a positive k-factor and the other two a negative k-factor.
Gladly, there is already ...
- 555
0
votes
1
answer
300
views
4-Wire Strain Gauge Measurement
I want to accurately measure the resistance of a single strain gauge, unaffected by lead wire resistance and with ratiometric ADC conversion to compensate for excitation drifts.
I know for RTD ...
- 93
0
votes
1
answer
92
views
Deriving Wheatstone bridge equation
I have the following circuit:
Here I have obtained the equation of Ud = U * ((deltaR / R)/(4+2(deltaR/R))). But I'm stuck on the part on how to derive that formula.
Any help or guidance is ...
user224075
1
vote
3
answers
239
views
Anemometer with opamp
This is related to an earlier question of mine, but I have a different follow-up question that I wanted to make a new post for.
I'm trying to understand more about how the below circuit works, ...
- 15
0
votes
2
answers
311
views
Constant-temperature anemometer circuit not behaving as expected
I'm testing a circuit design for a constant-temperature anemometer using an NTC thermistor as the sensing element, and the behavior of the circuit has me confused. After struggling with various ...
- 15
0
votes
2
answers
979
views
How to measure multiple objects' weights with load cells and Raspberry Pi 4?
I am working on a class project that involves a raspberry pi and strain gauge load cells. .
The goal is to measure the weight of two or more objects using a set of two load cells (In the picture it ...
- 65
0
votes
1
answer
251
views
How to calculate gain of wheatstone bridge+differential amplifier? [closed]
Can someone help me solve this task?
The schematic shows that the sensors are connected in series parallel and that the measurement is done using a Wheatstone-Bridge and a difference amplifier.
A) ...
2
votes
1
answer
79
views
Confusion with Wheatstone bridge resistor terminology in datasheets
An off-shelf instrumentation amplifier manual has the following indication for Rb:
And this force-transducer gives the following resistance parameter:
I guess Rb is each single resistor value of ...
- 408
1
vote
1
answer
317
views
How to make a full Wheatstone bridge with 4 tee-rosette strain gauges?
I am in the process of making a full Wheatstone bridge. I was told to use 4 tee-rosette strain gauges (with axial and radial components in one gauge) to temperature correct the signals. I am ...
0
votes
1
answer
134
views
How a wheatstone bridge is used in operational amplifiers? [closed]
How a wheatstone bridge is used in operational amplifiers?
0
votes
2
answers
80
views
How do I get a stable 15V signal without a variable power supply?
I'm studying mechanical engineering (inb4 easy major), so my knowledge of EE is limited and sequestered to blind application.
I need a stable 15V supply for a wheatstone-bridge strain sensing circuit,...
2
votes
1
answer
383
views
Using an op amp to balance a Wheatstone bridge by heating a sensor wire
I'm attempting to create my own hot wire liquid water content sensor, the control circuitry of which is similar to many hot wire anemometers:
simulate this circuit – Schematic created using ...
- 21
1
vote
2
answers
53
views
How to handle disconnected resistive sensor?
I'm trying to connect a PT100 thermo probe to an Arduino project to measure water temperature. After some research I have found and adopted a design using a Wheatstone bridge and an instrumentation ...
- 13
2
votes
1
answer
959
views
How to calculate the value of the thermistor based on the output voltage of this circuit
I recently bought a board that consists of this circuitry. It came without an instruction whatsoever, so I have to figure out how to measure the temperature based on the output voltage at the To.
The ...
- 123
0
votes
1
answer
134
views
Signal lines from transducer made common by op-amp
I am trying to amplify the difference between signal lines off of a Wheatstone bridge based force transducer. I've wired up an LM358N Op-Amp as shown below in a differential amplifier.
With R1=R2=...
- 1