Questions tagged [load-cell]
A load cell is a transducer which converts force into a measurable electrical output.
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Thermoelectric EMF problem for low voltage measurement load cell
The resolution of a load cell is highly dependent on its capacity. That's because the higher the resolution and the higher the capacity, the smaller the voltage change. For example, many companies ...
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Comparing ADC noise parameters
I'm looking at two ADC parts the ADS1230 and the ADS1231; the 1231 is an almost pin-compatible upgrade (if you don't need the ×64 gain setting) which provides 24-bit resolution and some more noise ...
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What is the ideal method of sensing whether 4 points on the bottom of a device are all depressed to indicate contact?
I am trying to place a sensor or switch on each corner of some desktop PCs so that if they are lifted an event is triggered like locking the computer or encrypting it.
So far I have considered small ...
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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 ...
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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?
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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 ...
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Question regarding the ADC MCP3201 interfacing with PIC16F72 microcontroller
I provide the 1.2 MHz clock to SCK pin to the ADC from PIC clock pin, but how I can receive the data from MCP3201 ADC, which provides a 12 bit binary data on SPI pin SDI of PIC? Buffer of PIC is 8 bit ...
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How do I remove bathroom scale auto shutoff feature?
I’m a software guy so please excuse any silliness in this question.
I need a scale which will not shut off on its own and continuously show changing weight values.
Although I may have no choice but to ...
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How can I synchronize load cell and sensor for sensor calibration?
I have made a glove with some cheap pressure sensors with weight ∝ 1/resistance.
DESIRED OUTPUT
I now want to create a dataset with columns "Actual Weight" and "Glove Sensor Readout&...
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HX711 load cells giving wrong readings
I have four HX711 cells in a Wheatstone configuration. I use them from home automation to measure bed presence. It worked correctly for a few weeks, but suddenly stopped working (cannot get any useful ...
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HX711 zero factor
I have three load cells (YZC-1B). These load cells' capacity is 50 kg. I guess I use Bogde's HX711 library.
In monitor, the zero factor for the first two load cells is 8,000,000, but for the last load ...
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Electrical noise in 18650 3.7V lithium batteries
I'm interested in knowing the electrical noise in Volts of modern 3.7V lithium batteries, specifically my model is NCB18650B, but since I don't have an oscilloscope I can't measure it. On the internet ...
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Question on load cell amp HX711
How do you make a load cell's amp HX711 measure both positive and negative values, or how do you set the center value for it? The main point is how to set the reference voltage (?) or something else ...
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Connector for load cell
I'm working on a scale that uses a tin-plated connector between the load cell and the PCB where the ADC is mounted. The connector is JST ZH (4pins) tin-plated.
During testing of this design, I have ...
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CS5530 - Read serial data through SPI [closed]
I am trying to read data from a CS5530 using SPI.
I have gone through the complete datasheet but I don't understand what is missing. I am getting the same value every time even after changing the load ...
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Wheatstone Bridge strain gauge thermal compensation design
I'm designing a full Wheatstone bridge for measuring the bending strain in a steel bar.
I have a circuit available to me that uses an ADS1232 to measure the output of the wheatstone bridge.
When ...
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Oscilloscope or bench multi-meter for ultra high sensor sample rate measurement
I need a device to measure the output of a load cell at very high sample rates. I am aiming for a sample rate of at least 100 kHz. For this goal, I wanted to ask if it would be better to use a bench ...
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Arduino Load Cell Limitations
I came across this forum in my research on load cells for a project at work. I had order the load cell and an amplifier/display but turns out there's no way for the display to show lbs it only shows ...
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Minimize load cell amplifier noise and interference INA122P
I am trying to simulate car pedals with load cells. For that I wired up 2x20kg load cells and 1x 100kg load cell each wired to a INA122P which join up at a stm32f103c8 blue pill board.
The circuit ...
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Calibrating 500 kg load cell with ESP32 and HX711 without putting actual 500 kg on it! 3 V excitation
I am making a 500 kg scale using ESP32 and HX711. It is battery powered and using 3 V excitation.
In calibration process , I increase the weight by 50 kg steps and read the HX711 output and then use ...
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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/...
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HX711 powered directly from coin cell
Is it a good idea to use HX711 in a project (personal weight scale) that is powered directly from a coin cell (CR2032) without any external or its internal voltage regulator? I shut down the whole ...
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Parallel load cells on a same current source
I need to read 4 load cells with relatively low resolution (12 bit is OK) and frequency (10 SPS is sufficient). The prototype used 2 ubiquitous HX711 breakouts with each powering two load cells in ...
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Dimming energy with load cell
I'm a lawyer with no technical background. I'm just a geek! :D
I wonder if it is possible without using a micro controller can a load cell dim the amount of energy supplied by a 3V battery?
The ...
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Connecting multiple full bridge load cells together with HX711
I am doing a project where I need to connect 2 or 3 full bridge load cells (the one with 4 wires) together. I have read that to have such an arrangement I need to connect the load cells in parallel ...
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Does shunt calibration of a sensor also correct for zero error?
In the datasheet for a load cell (shown below), it says that shunt calibration data is given, also they have mentioned the zero balance. Does the shunt calibration consider zero balance? Meaning, do I ...
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Do ADS12XX circuit need an amplifier?
I'm working on a project that use various analog sensors (load cells, microphone, pressure, etc.) All of them have an analog standard output (mv/V). I'm using a Raspberry Pi. I want to choose a module ...
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Does creep always occur with load cells, or is there an optimum weight capacity?
I want to make a scale which I will place under a wood stove (downdraft gasifier) to measure the amount of wood that goes into the wood stove. The amount of wood which is being measured will be ...
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TRT-25 and Arduino Uno
I need help on a project I am working on.
We are trying to integrate a reaction torque sensor and I am having a hard time deciding how to go about it.
Previously I assumed that like my load cell I ...
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Need help fault finding a custom PCB
I am designing a custom circuit board for a CG scale test instrument to find the centre of gravity for model airplanes. My design is based on the model here: https://github.com/olkal/CG_scale and it ...
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Instrument amplifier output continuing drifting
I'm using AD8226 to amplifier differential signal coming out of a load cell, the output of the AD8226 goes straight into the AD7190. My load cell is full bridge with output impedance of 350 Ohm, ...
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What check can Ι perform to verify that a load cell is operating properly?
About five years ago I was tasked to develop the software for a small custom made testing machine (everything is custom-made from frame, to the measuring system). Last year, I was volunteered to &...
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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 ...
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Active guard shielding for instrumentation amplifier
I want to use the the AD8221 amplifier as a conditioner for my load cell. I saw that to reduce noise I can use an "active guard shield driver" between the "REF" of my amplifier and ...
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How to change get positive value on my weighting Scale?
My weighting Scale is working fine when I keep weight after the start. But I am getting stuck when I keep weight before starting my weighing device. When I do this auto-calibrate with available weight....
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What kind of a sensor does a arcade punch (boxing) machine have?
I am working on a project, where I have to measure the pressure exerted by a punch. I am trying to understand how an arcade machine works, and see if I could replicate the same mechanism in my project....
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HX711 with RaspberryPi and python
I have been working to create a digital scale for IOT project, using HX711 ADC.
The problem
Since it is crucial to have wifi connection, I use Raspberry Pi, to control the scale.
Everything works well,...
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AD7190 voltage reference
I'm using AD7190 with a 4-wire load cell to build a pressure acquisition board. From ADI reference design(CN0102), I understand that connect sense+- lines of a 6-wire load cell to the ref+- pin of ...
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MCP3561 Configuration registers resetting upon relay activation
I am looking for advice on how to solve a problem I'm encountering with my PCB project. The application involves reading a weight from a cluster of load cells and activating a relay that controls a ...
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Weight sensors? Load cells?
Apologies for a novice question. I'm looking into designing a system which would detect presence of certain objects on say a shelf. I think (not sure) I need to use "load cells" for that. Is ...
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Homemade NAU7802 breakout board not preforming like reference
I am designing an NAU7802 breakout PCB for a small weight scale project I'm working on, but I've had bad luck getting it working. I am comparing its performance with the Sparkfun Quiic Scale (their ...
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Use of a three wire load cell
I am currently doing a project which requires the measurement of forces on a surface and to achieve this we are using 3 wire load cells.
The problem that I am running into is no matter how I orient ...
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HX711 and 50kg load cell - possible update speed / dynamic load
I bought this 50kg load cell and an hx711 which I want to connect to my raspberry pi zero.
I'm wondering how accurate they are if I load them with a dynamic weight.
To take a simple analogy: could I ...
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HX711 noise, but only in a specific environment
I'm working on a small project at my farm to automate vegetable weighting. The system consists of an STM32 MCU, some additional ICs (matrix decoder, parallel-serial converter for some push-buttons etc....
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Suitable op-amp and voltage regulator for 16-bit ADC
I would like to use the AD4008 16-bit ADC from Analog Devices to sample a load cell. I also need a linear regulator and driver amplifier and instrumentation amplifier.
I am curious to know if these ...
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Reduce load cell creep and drift programatically
I am trying to build a weigh scale and have read through the parameters that affect its reading in the long run. My question is can we reduce the Creep and drift of the load cell by compensation ...
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What does %FS (Full Scale) represent in load cell?
Lets say that a load cell has these specifications:
Rated Load = 500 g
Rated output = 1 mV/V
Excitation voltage = 12 V
Creep = 0.02 %FS / min
Then the output range should be 0--12 mV.
Does %FS mean ...
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Why aluminium for load cells?
I am currently working with load cells for weighing small masses. Almost all of them, as far as I have looked, have been made from aluminium. Given that repeatability is critical, why aluminium and ...
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Linearizing a load cell
As I understand it most load cells (all?) are only approximately linear. To improve the linearity would a 3 point calibration be sufficient? For example, at no load, half load and maximum load. If so, ...
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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 = ...
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