Questions tagged [load-cell]
A load cell is a transducer which converts force into a measurable electrical output.
187
questions
0
votes
0answers
17 views
problem with GML692 load cell and hx711 stm32
I want to measure weight and send it to uart using a GML692 loadcell and hx711 ADC module using stm32f103ret6. I have several problems.
1-firstly, I should put pressure on side 2 in order to increase ...
3
votes
2answers
136 views
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 ...
1
vote
0answers
39 views
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 ...
0
votes
2answers
25 views
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 ...
1
vote
2answers
150 views
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 ...
2
votes
0answers
41 views
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, ...
1
vote
0answers
43 views
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 &...
0
votes
0answers
32 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 ...
8
votes
4answers
608 views
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 ...
0
votes
2answers
40 views
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....
6
votes
4answers
806 views
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....
3
votes
1answer
151 views
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,...
0
votes
1answer
69 views
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 ...
0
votes
0answers
90 views
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 ...
-1
votes
1answer
39 views
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 ...
2
votes
0answers
194 views
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 ...
2
votes
0answers
39 views
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 ...
0
votes
0answers
30 views
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 ...
0
votes
0answers
42 views
Effects of bootlace ferrules to connect load-cell with amplifier
My colleague and I had an argument about whether or not to use bootlace ferrules for a load-cell (4 stranded wires + 1 shield | 100mg precision | OIML C3 | max. 3kg) going into an amplifier (spring-...
1
vote
0answers
94 views
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....
0
votes
1answer
81 views
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 ...
0
votes
0answers
87 views
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 ...
1
vote
1answer
204 views
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 ...
2
votes
1answer
62 views
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 ...
0
votes
2answers
66 views
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, ...
0
votes
1answer
77 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 = ...
1
vote
2answers
1k views
Load Cell ADC HX711 Alternatives?
Looking for an HX711 ADC alternative. Sparkfun sells a pricey breakout board with the chip, but I cannot source the IC anywhere online for some reason 🤷♂️. Are there any ADCs out there that have a ...
0
votes
0answers
49 views
Load Cell Decreasing Output
I built the following weight system using a Load Cell and Hx711.
I am using an Arduino UNO and running the calibration sketch in HX711 library.
However, I noted one interesting behavior that you ...
0
votes
1answer
91 views
Regarding PLC and several input/ output modules
I have to use more than 40 servo motors and 20+ load cells using PLC. But the problem is that I have to use many I/o modules ( that is costly and hectic). Can I reduce the no of I/o modules by any ...
0
votes
0answers
526 views
How to connect two load cells to one HX711?
I have two 5 kg load cells and one HX711. The project's goal is to connect them together, and measure the weight of the same object. I would like to get the average in order to make my calculations ...
0
votes
2answers
351 views
How does the HX711 circuit work?
This scheme will be designed for weight scales. Why is there a transistor installed.
And I want to understand why need capacitors and resistors in this circuit. (their purpose)
The documentation does ...
0
votes
1answer
530 views
HX711 chip not working
I'm working on an electronic weight scale using MSP430 and I need your help:
I've written the code using Energia and I've used the HX711 module for testing and everything works just fine. The final ...
0
votes
1answer
117 views
Can I “sum” internal ADC channels to achieve extra bits resolution?
First of all I am a newbie in electronics.
I am building some weight scale applications using (as seen everywhere) load cells wired to a HX711 ADC and a ESP8266. I am now giving a try to the Texas ...
0
votes
2answers
337 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 ...
1
vote
1answer
141 views
What would cause an ADC to stick on an arbitrary value?
I have a differential ADC (HX710) that I am using to interface a load cell. The wiring is as follows with (J4) going to the load cell:
Mostly, this reads very reliably and accurately. However, ...
0
votes
0answers
558 views
Load cell continually increases or decreases
I am using a load cell that is wired to a HX711 amp in the following manner:
. I have been attempting to use the calibration example code that is included in the HX711_ADC library (code listed bellow)...
1
vote
1answer
517 views
3 wire load cell and HX711 weight compensation
in my project I use 3 wire load cell (like this (3wire 50kg) but mine are purchased from ebay) and HX711 for weighing.
My wiring is like this (but i use Arduino mini pro 3V3):
Apparently it should ...
1
vote
2answers
67 views
What is the nuance between these electrical parameters in this load cell datasheet?
A load cell has the following specs:
I've highlighted the relevant part in yellow. There are two parameters called Uref and Bu. Both of them is about the excitation voltage for the Wheatstone bridge ...
0
votes
0answers
685 views
Is AD7794 a good alternative to Hx711 for multi-channel ADC?
note: Electronics isn't my main background so I might make silly mistakes. I did read the datasheet but don't understand all the terms despite my effort. Suggestions are welcome.
AD7794 (datasheet) ...
0
votes
1answer
50 views
Load cell behaving weirdly. Output magnitude of force depends on which side is held and which side force is applied
also asked at: https://forum.arduino.cc/index.php?topic=670246.0
I have a generic load cell (image) and am using Hx711 which is connected to arduino. The code is from Instructables.
When I fix and ...
4
votes
2answers
2k views
Connecting 4 load cells in parallel
I have 4 strain gauge load cell to calaculate actual weight.I want to use summing method for 4 output signals. I searched at internet for summing box schematic I found this pic
Now if V1 , V2 , V3 , ...
0
votes
2answers
86 views
Use a precision opamps or instrumentation amplifier for load cell application
I'm making a low power weighing scale with good precision. I'm contemplating if it'll be better to build a instrumentation amplifier with discrete OPAMPs of LPV821 which is low power (Iq 650 nA), high ...
0
votes
1answer
42 views
Load cell amplification circuit operation
Here's the reference circuit for amplifying the signal from a load cell with precision OPAMPs as per the MAX44248 datasheet. Can this OPAMP circuitry be explained please. What's the relation between ...
0
votes
0answers
189 views
Loadcell strain gauge with 10 V excitation
I am designing loadcell (spec) measuring using 24-bit adc (MCP3561) with excitation 10 V. But I couldn't find the reference design for 6-wire loadcell that its sense pins connect to ref+ pin of ADC. ...
0
votes
0answers
95 views
Two load cells on one HX711
I need to read 4 full-bridge load cells about 10 times per second. Are there any drawbacks of connecting two cells to A and B channels of HX711 and alternating reading between them?
I understand that ...
0
votes
0answers
43 views
Raspberry pi not getting any data from hx711
I'm trying to combine two boards into one: SparkFun Load Sensor Combinator(basically just a wheatstone bridge) and SparkFun Load Cell Amplifier. The data will be transmitted to a Raspberry Pi 3 so ...
0
votes
0answers
33 views
why is the reference of strain gauge changed depending on gains of amp? use ina128 and ad8542
I made a circuit for a load cell. It is available but when it is applied to the strain gauge, it has a problem.
Reference voltage : 1.65 V
When I measured value of load cell, I can see the change ...
0
votes
0answers
135 views
ADC value changes with changing power supply
I'm measuring weight using hx711 ADC and load cell.
HX711 schmatic:
I use 12V 1A power supply and 6V/4Ah dry cell. Also I use MT3608 boost converter to increase battery voltage to 12V because ...
1
vote
2answers
473 views
HX711 and 3 load cells
I am doing a small project with ESP32 and HX711 and I need to have 3 load cells.
Like this one:
I am totally newbie in electronics, my ground is programming.
What I found are projects with 1, 2 or ...
1
vote
1answer
187 views
Reading and interpreting output sensitivity of a load cell from data sheet
I'm given these ratings /spec for load cell / sensor:
Range: 0-200kg
Output sensitivity: 0.7 ± 0.15mV / V
Nonlinear: 0.05% F.S
Hysteresis: 0.05% F.S
Repeatability: 0.05% F.S
Creep: 0.05% F.S/3min
...
