Questions tagged [current-measurement]
Measurements of the current flowing through a circuit
1,148
questions
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2answers
46 views
Multimeter as a variable load
I want to measure the current that can be supplied from a lead acid battery I have. (To know it's remaining current supplying capacity). To measure current I need to connect a load and an ammeter (...
0
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3answers
93 views
Is current different across resistors in a voltage divider?
I know that this may seem like a simple question but I want to know whether the currents across the resistors of different values are equivalent.
For example in the circuit depicted below, if I were ...
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2answers
45 views
LTSpice (windows) - current labelling
I want to measure current going into and out of an op-amp. However, when I do .op command, I am not able to understand which current is being referred to here. ...
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0answers
48 views
Need help with a solution for current measuring
I need a solution for measuring current through a load. It is a 15W load at 230 VAC or 24 VDC. I found the TMCS1100A4 from TI (datasheet). It's very nice because it can measure both AC and DC easily ...
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1answer
34 views
How to bypass current sensor (ACS712) default 2.5V voltage output in buck/boost converter PCB
I'm having a bit of trouble coming up with the most practical fix for my buck/boost converter PCB. To give a bit of an overview, I'm using a current sensor to read the current value through an ...
0
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1answer
39 views
An Integrator Reset Circuit not working properly
I am trying to integrate the output of a Rogowski coil , with an inverting integrator with a reset circuit. I want to have the voltage level 0V during the off time of my switch, however after reset ...
0
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1answer
26 views
I'm having issues setting up the LM13700 as a floating resistor and measuring the correct resistance values
So I'm still learning how OTA's work, and have an application using the LM13700 as a floating voltage controlled resistor as seen below:
I'm using +/-12V rails for this circuit. I have it set up so ...
1
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2answers
64 views
Hall current sensor noise
For my project, I need to measure AC current for a 220V load (a more detialed description of the initial approach and problems can be found here.
I'm using an ACS724 for +/-5A; the next step will be ...
0
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1answer
33 views
control dc dc converter board with the microcontroller
I want to control a bidirectional buck boost dc dc converter evaluation board evaluation boardusing STM32 Nucleoboard MCU. The evaluation board is having only I2C interface. I am connecting a 12V lead ...
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0answers
39 views
Current measurement USB to serial UART converter or Arduino
I want to perform a current measurement of an electronic module with the help of a multimeter with log function.
Can I just couple the module to a USB to TTL serial UART converter and perform the ...
1
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1answer
61 views
Calculate the electrical current density (international metric systeml )
I have a doubt about a result on a result. I have to calculate the electrical current density like $$\frac{\,\text{A}}{\,\text{m}^2}$$ I have the following parameters:
$$r=1\,\text{mm} =10^{-3}\,\text{...
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1answer
39 views
How to know the status of a two way switch through MCU
My project is this one that I asked earlier (except the fact that I'll be using SPDT switches) Two way lighting
What I'm asking can the MCU detect if the circuit is closed (whether by the physical ...
3
votes
2answers
113 views
Programmable gain Transimpedance amplifier for 4-5 decade resistance measurement using Pulse voltage/current
As you can see from my previous question, I am trying to measure resistance within the range of 200k-60 ohms (around 4-5 decades). I will be using a pulse (5us pulse width and 50ns each rise and fall ...
0
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1answer
51 views
Advice regarding AC current measurement using a microcontroller
The goal is to design a simple and compact (as simple and compact as possible) module to perform AC current measurement (for one or two 220V loads) using a microcontroller. One of the issues is that I ...
0
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2answers
66 views
Raspberry Pi 4 won't boot with current sensor connected
I have a problem when trying to boot my Raspberry (c03111) with a current sensor connected.
The Joy-it COM-KY053ADC is used to translate the analog signal of the current sensor (LEM Hass 50-s) to I2C ...
0
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3answers
126 views
Why is my multimeter stopping device from booting when measuring current?
I am using a BK Precision 2709B multimeter and attempting to measure the current of a device that runs off of a ~3.7V battery. The device boots up, initializes and then goes into its lower power state....
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1answer
108 views
Why is my multimeter reading such a high/erratic current?
Newbie to electronics here.
I have a simple circuit consisting of just a 9V battery and an 820 ohm resistor. I was trying to measure the current with a multimeter (by opening the circuit between the ...
2
votes
1answer
65 views
Designing a current sense circuit to measure a wide range of resistances and noise considerations
I have an application in which I have to design a current sense circuit in order to measures the resistance of a load resistor that can have values between 200kohms and 60ohms. The input voltage of ...
4
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5answers
227 views
Accurately amplifying a number of current sense transformers
I've got 16 current sense transformers that are being used to monitor AC loads. The SCTs are current output type, producing 50mA on a 100A load. The maximum burden resistance is 10Ī©, thus the voltage ...
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0answers
49 views
Ways to visualize current return paths on a PCB board
Overview
I'm writing a paper on PCB layout, and included with the paper are some evaluation boards. Generally the boards demonstrate different layout concepts (bypass-caps, trace widths, controlled ...
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1answer
24 views
BLDC 3 phases low side current sensing
Hello I'm struggling with calculation of BLDC motor current. I'm using MP6540 driver for controlling BLDC. I can measure voltage (adc) and after using appropriate formula from datasheet I got current ...
0
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3answers
93 views
Determining current through a short circuit
Edit: So I have to calculate the current through the short circuit and what I thought of is:
Applying current divider across 4kohm and then the 2kohm resistor right below to get their respective ...
1
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2answers
32 views
CD4052 multiplexer with different input voltages
I've been working on designing a PCB for my indoor garden and i'm facing a problem i dont understand.
In my design i use a multiplexer (cd4052), to choose which sense resistor my current sensing chip (...
0
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1answer
28 views
MC34063A power consumption calculation
I'm designing a circuit based on the MC34063A switching regulator to step up 3.7V to 8V.
The 3.7V for Vin comes from a 3.7V Li Ion battery and so I'm trying to calculate the battery life. I'm a bit ...
0
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0answers
26 views
Current Sensing IC (MAX9929F) Query
I am using a MAX9929F Current sensing IC and I have a question to someone to may have used it before, or may have some experience with these types of circuits.
The circuit I built around the IC is the ...
0
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2answers
53 views
Asymmetrical output
I was searching for a current sense amplifier for measuring the current between a power supply and a battery i.e high side.
I found the INA240A1 (evaluation module here).
When I look at the ...
0
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2answers
39 views
Calculating DC motor rotations from current readings
Situation: I'm using a brushed DC motor to open and close the vents of a greenhouse and I would like to know the exact motor location for more granular temperature control. Motor moves at different ...
-4
votes
2answers
157 views
Mains Power Metering
please see this schematics:
Please look at the 3 transformers to the right of the picture (above the houses). They are current transformers.
On the other hand, we have an SGM30C2 electrical meter. (...
1
vote
1answer
44 views
Voltage divider resistor sizing to minimise voltage variance
I've got the following circuit design simulated in SPICE, this is a copy of the EmonPi circuit design (https://github.com/openenergymonitor/emonpi/tree/master/hardware/emonpi/emonpi_V1_6).
I've got a ...
1
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1answer
40 views
Hall effect current sensor ACS712 for battery application
I want to measure the current of 12V lead acid battery for charger application. So mostly, I need bidirectional current sensing.The current measurement can be done using shunt resistor or using hall ...
1
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0answers
70 views
Current sensor that works in 0nA-250nA range?
Is there any current sensor capable of sense very low current ranges from 0nA to 250nA?
I would need to sense the current produced by this photodiode: GVGR-S11SD (http://www.geni-uv.com/download/...
2
votes
2answers
83 views
Switchable current shunt resistor
Looking at the reference design given for INA826 in the image below, what would my best options be if i wanted to replace J8 with something allowing me to switch in R19 (sense resistor) from a ...
0
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0answers
53 views
Can I use this circuit to control model trains with?
I am currently researching and developing several arduino/attiny projects for model railway applications.
One of the projects is a method to 'catch' an analog train and gently slow it down using a ...
0
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0answers
33 views
Ion current measurement
I have a few questions:
To measure the ion current in air plasma from a source that works in pulses, what method is best for ion current measurements? Is it by using a Rogowski coil or by measuring ...
0
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0answers
48 views
Analog current sensor design help needed
I have been thinking for some time about a circuit. I have been a digital designer for most of my career, and have recently begun studying analog again, and find it a welcome challenge. I am trying ...
0
votes
1answer
60 views
Find the voltage Vab and current of the circuit I
I was asked to find the voltage Vab and the current of the circuit I.
I tried finding the voltage in ab using voltage divider, but I have two voltage sources and I don't know how to make the ...
0
votes
1answer
43 views
Correct arrangement of current sensing resistors for a BLDC motor?
I am designing the current limiting (fault detection) circuit for a three phase BLDC motor and I wanted to ask, If I have three switches on at any given time (180 degree commutation) than should the ...
0
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0answers
35 views
Offset of amplifier input voltage of shunt current amplifier
I'm trying to build a 20A E load and decided to use a 0.01Ohm shunt for the current measurements and set so I needed to amplify the shunt voltage by 10 using the "rail to rail" AD4522-2.
At ...
0
votes
1answer
41 views
Using High side current sensor as a low side current sensor
I have a very small question to ask. Is it ok if a high side current sensor such as the MAX9929 be used as a low-side current sensor as well? Or should I look for some parameter in the datasheet. The ...
0
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1answer
43 views
Return path magnetic field on hall effect current sensor
We would like to use a toroid core and hall effect sensor shown in the figure below for measuring current in an Electric Vehicle from a battery pack.
Questions are:
Would placing the wire carrying ...
0
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0answers
53 views
How do i measure current in 10uA till 10A range in steps of 10uA?
I'm planning to build a circuit that measures the current from uA till 10A DC Line. Initially I thought of using HECT, but it is having better accuracy in higher current range. so I'm figuring out if ...
0
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2answers
69 views
Correct way to measure circuit power consumption before or after LDO
I have created a low power MCU project, and I want to measure the power consumption.
I am confused with:
a) the correct way to place the ammeter, before (picture A) or after (picture B) my voltage ...
1
vote
1answer
39 views
Id, Vds calculation
Simple and strange, looking at datasheet of BSS138 (Graphs) for this circuit below which is always ON Saturation mode Mosfet, Rds-ON = 3.5 Ī©, VDS-ON = 0.1 V to 0.2 V.
Id should be 16.66 mA but ...
0
votes
0answers
29 views
Inexplicable curve shape of short circuit current measurement on synchronous machine
I'm doing some experiments on a synchronous machine with follwing data:
nominal power: 5kVA
nominal stator voltage: 380V phase-phase
nominal stator current: 7.6A
nominal frequency: 50Hz / nominal ...
1
vote
1answer
51 views
Sensitivity of a sensor
I have a current sensor (sensitivity is 22mV/A) which is being used to measure AC current with its time stamp data.
I have connected this sensor to an ADC (12 Bits resolution
Can somebody please let ...
0
votes
1answer
80 views
Can you prove that electricity was generated by a photovoltaic cell?
I am wondering if it would be possible to build a photovoltaic cell that kept track of the electricity it generated (perhaps with a built-in meter), such that you could not trick the meter without ...
0
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1answer
84 views
Transimpedance amplifier oscillates
UPDATE:
I have removed switch and shielded cables and improvised the board as shown in below image. The transimpedance amplifier is stable. I applied four signal of 10kHz, 1kHz, 1Hz and 100mHz of ...
0
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1answer
59 views
How to find the power supplied by the ideal current source? [closed]
In this question I have already found the current in the three meshes given using mesh analysis, they are (i1 = top mesh , i2 = bottom left, i3 = bottom right).
How to find the power supplied by the ...
1
vote
1answer
43 views
Current loop receiver (minimal implementation)
I'm looking for a minimal design of a current loop receiver with the following characteristics:
I_in 0-20mA
U_in (-24) 0 - 24V.
U_out 0 - 3.3V
The precision doesn't need to be very high - an output ...
3
votes
5answers
337 views
Common ground in low side current sensing
I've asked this question a while back and user/Transistor told me that the circuit will be floating and drift without a common ground, he suggested a virtual ground. but in this case we already have a ...
