Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [wheatstone-bridge]

A circuit to measure an unknown resistance.

A Wheatstone bridge is an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component.

Circuit Diagram

The image is taken from Wikipedia.

See Also

208 questions
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Digital bathroom scale circuit - how it works?

I'd like to understand how the digital bathroom scales work. I was able to gather that there are four three-wire load cells connected into the Wheatstone bridge as suggested below. The load cells have three wires which seem to be connected as if…
YSN
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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/MCP3428, with added benefit of smaller PCB…
Maple
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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 power voltage \$V\$, the ratio between the bridge…
Brethlosze
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3-wire load cells and wheatstone bridges from a bathroom scale

I am involved with a 4H project looking to take some weight measurements with bee hives and am trying to figure out some 3-wire load sensors to do just that. I have four 3-wire sensors (load sensors/strain gauges) from one bathroom scale (each…
user37997
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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 just "Q1, Q2, Q3, ..." and I know that the…
MicroservicesOnDDD
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What is the point of a Wheatstone Bridge?

What is the point of a wheatstone bridge? Everywhere, like here says that it's used for measuring an unknown resistance, but I don't understand why it's so complicated. Can't you just use a voltage divider to measure resistance? The equation for…
kenntnisse
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Where is this noise coming from? 200 kohm Wheatstone bridge

I have a Wheatstone bridge I want to use to measure a resistive sensor. At the moment, all four arms are fixed resistors, while I get the circuit set up. The noise in the circuit is much larger than I expected, and I can't work out why. simulate…
Jack B
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Wheatstone bridge sensitivity and accuracy

From my earlier question I was able to wire up 2 SEN-10245 weight sensors (each forming one half of a wheatstone bridge) with an AD620 InAmp & 47 Ohm resistor (to set the gain to ~1000). I then ran the signal through the MCP3008 Analog to Digital…
Anconia
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Is the Excitation Voltage of a load cell a strict specification?

When using load cells (or strain gages generically), is the Excitation Voltage spec provided as a strict minimum -- or is it just a recommendation which one can go below as long as one is OK with a smaller full-scale output? The details: I wish to…
boardbite
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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 Wheatstone brige (bottom-left resistor is the strain…
dodod
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Connect HX711 to a three wire load cell

I have the following load cells: I'm using the following HX711 amplifier Every guide i can find on the internet describes how to connect a load cell with four wires to the amplifier. How can i connect a load cell with three wires to the…
David Junker
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How to Read Wheatstone Bridge negative voltage with Arduino?

I have a half bridge setup with strain gages and a INA126 to amplify the voltage. I can read the voltage fine when the lever is bent one way, but when beding the lever in the opposite direction I don't get any reading. I'm guessing it's because…
criverapr
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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 another device we are building. We have a pretty good…
Ravenant211
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4 wire RTD (PT100) in a wheatStone bridge

I want to connect a 4 wire RTD PT100 in a wheatStone Bridge. I tried searching on internet but only up to 3 wire configurations in bridge are available or circuits using other ADS IC's are available. But I want to do it in a Bridge…
Priyanka
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What is the value of the current (i) and what is the right way to do it?

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 unbalanced Wheatstone bridge and found that the…
user208474
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