All Questions
Tagged with current-sensing current-measurement
32 questions
2
votes
7
answers
1k
views
Can a 4 to 20 mA current loop be measured without using a resistor?
Background
There is an electrical system typically consisting of a 4 to 20 mA transmitter and receiver.
simulate this circuit – Schematic created using CircuitLab
So far, everything is working ...
- 678
-1
votes
0
answers
18
views
ACS71020-I2C data read problem
I recently working on ACS71020 with I2C communication .I will attach my module details, code and my results. The slave address of the I2C keeps changing and even If I turn on the supply the measured ...
- 63
2
votes
0
answers
30
views
Window current detection through a current sense differential amplifier and a comparator
I'd like to implement a circuit to detect the over-current through a grounded load. The limits for that current are either 3mA DC current or -3mA and 3mA in case of bipolar AC current. I want to ...
- 97
1
vote
2
answers
94
views
How to sample current in high-kHz to low-MHz [closed]
I am working on a project that, at its simplest, is a switching circuit (either a half-bridge or single switch) connected to a resonant filter. I need a way to measure/sample the current going from ...
- 41
11
votes
9
answers
2k
views
Is it feasible to measure voltage drop across 0-ohm jumper resistors to determine excessive current draw?
We design very low-power devices which in standby mode use about 8 µA of current. They are powered by 3 V lithium primary cells and are designed to last for many years.
Every now and then we see a ...
- 34.9k
0
votes
2
answers
82
views
Current measurement with LT6015, simulation doesn't work
I'm trying to simulate high side shunt resistor current measurement using LT6015 op amp, but the simulation doesn't work I'm always having the same output even if I change the current. Can somebody ...
- 3
0
votes
1
answer
420
views
LTspice simulation of a fluxgate excitation circuit with H bridge driver, Op-Amp and comparator not behaving as expected
Please see the following LTspice schematic:
This is an excitation circuit for a fluxgate current sensor. The inductor L1 models the magnetic core's B-H loop and dimension along with a sensing winding ...
- 93
1
vote
1
answer
60
views
How to sense if a heater is plugged and on
I want to remotely check if one of my home sockets (which happens to power a heater) is transmitting current or not. I do this as a hobby project, so my main priority is to learn through the process ...
- 1,385
2
votes
3
answers
341
views
How can we say this current sensor doesn't measure DC?
Digikey is saying this current sensor "CS0305B" from CUI Devices can measure AC and not DC.
But in datasheet there is no reference or note mentioning this current sensor will not measure DC.
...
-2
votes
1
answer
67
views
Current sensor for sensing 6 mA DC & 30 mA AC current [closed]
I want to sense very low currents for both AC & DC for an EV charger application. General AC & DC sensors do not have that much range to sense the current. Please suggest some good component ...
1
vote
2
answers
568
views
What does sensitivity mean for a current sensor when given in "mV/N" or "mV/mT" rather than "mV/A"?
I have been analyzing various datasheets of current sensors and majorly getting sensitivity given in "mV/A," from which I understand the output voltage per 1 ampere. I do not understand it ...
0
votes
0
answers
303
views
Current sense resistor vs transimpedance amp vs hall effect current sensor for instrumentation?
I'm using a photomultiplier tube; this creates a current output relative to the number of photons incident to it, on the magnitude of microamps. So, I need a precise and accurate way of measuring very ...
- 107
1
vote
2
answers
241
views
Current Sense Amplifier / Differential Amplifier Negative Voltage On GND pin OK?
Right now I'm picking a current sense amplifier for my application, and I'm looking for for amplifiers with maximum offset voltage of below 50uV (and offset and bias currents in nA/pA range).
Luckily, ...
- 3,673
0
votes
1
answer
353
views
Isolated Current Shunt Amplifier
I have twenty isolated power supplies (around 40 V max) which need to have their current draw sensed and monitored. I'm currently using a TI INA138 current sense amplifier, which sort of works.
...
- 193
2
votes
2
answers
828
views
Measuring PWM controlled current with a microcontroller
I want to measure current using sensor MLX91220 which gives output in analog.
I have battery that I charge and discharge via switching MOSFET and want to measure current on this grid.
Problem is that ...
- 525
0
votes
1
answer
901
views
Microamp-milliamp Measuring Circuit: will my circuit work? Feedback/Advice
I'm developing a device which must be able to measure milliamps and microamps on one of its lines (down to 1 microamp, but also clearly seeing if it's less than 1uA). It's going to be DC of different ...
- 3,673
1
vote
1
answer
382
views
Current sense op-amp with integrated shunt vs expensive resistor
To simplify my question lets assume:
I need to convert +/-7.07A RMS AC current into +/-707mV RMS voltage with high acurracy (0.1% or better).
It may be also higher voltage, up to +/-2.5Vpk.
For now ...
- 6,064
0
votes
1
answer
368
views
Current Sense Amplifier Potentials
I'm trying to implement a current sense amplifier in my application, but I have a question about setting it up with regards to current flow.
Basically, in this case, you put a very small shunt ...
0
votes
3
answers
889
views
Current Sensing on positive and negative voltage rails
I'm working on a design that uses two separate buck regulators to generate a positive and negative voltage, and I'm trying to implement current limiting with a current sensor. However, I am running ...
1
vote
1
answer
695
views
High voltage and cheap differential amplifier
Can I use a LM324N (very common) op-amp to act as a high-side differential current sense op amp at high voltage?
The Differential Amplifier
The differential input voltage rating is 32v, but my load ...
- 924
0
votes
1
answer
32
views
Current monitor output doesn't respond to load changes
When I physically build this circuit the output voltage doesn't response to load variation.
The voltage across the sense resistor is definitely increasing when decrease the load resistance, the ...
- 377
0
votes
2
answers
2k
views
How to connect multiple sensors to single PLC input?
Hello. I have a scenario where I have multiple PNP "error signal" from several sensors (let's assume 3 for now). If the sensor output is HIGH, then there is error. If the sensor output is LOW, then ...
0
votes
1
answer
121
views
Current transducer - understanding of turns ratio connection
I'm using a LEM LAH 25-NP current sensor and I don't understand the recommended PCB connections in the table from the datasheet. I understand the first one, but what is with the second and third? What ...
- 194
0
votes
3
answers
694
views
INA168 vs INA169 High-side current sensing
I have read the datasheets of the INA168 and the INA169 and can't see any difference, other than internal resistors value and quiscent current (25uA for INA168, 60uA for INA169). Those two were even ...
3
votes
3
answers
17k
views
ESP32 using acs712 give wrong values
I'm trying to measure current with acs712 30A current sensor connecting to NodeMCU-32S but I'm getting wrong and unstable values. For zero current the ADC pin should read value of 2048 (esp has 12 bit ...
- 91
0
votes
2
answers
412
views
Overcurrent Sensing
I am designing an overcurrent protection circuit. I am sensing current with a LEM sensor across a sensing resistor of 16.5 ohm. The voltage drop for maximum current is 2 V. In the next stage I am ...
- 165
0
votes
0
answers
254
views
High side current sensing in BLDC motor?
I want to measure DC current flow through the 48 V battery in bldc motor (through Inverter circuit). Are INA 282, INA 169 work properly or not? Since my battery motor specification is 48 V, 5 Amp, 250 ...
- 79
0
votes
2
answers
181
views
Real Time AC Current Sensing [closed]
I'm trying to analyse the harmonics present in different household devices's current waveforms. For this, I need a CT based current sensor which can sample data quite accurately and quickly (around 5% ...
2
votes
1
answer
864
views
High side, high voltage, micro ampere current sensing
I am working on a project in which I am required to sense current in micro ampere range from a 2 kV power supply. Here is a link of an article which I am referring.
https://www.analog.com/en/technical-...
- 51
1
vote
3
answers
2k
views
Spikes - DC Motor Current Sensing
I'm using a drv8838 to run a small dc motor (<1A). For current sensing I set up a INA199 (see layout). I'm also using a RC lowpass with a cut off frequency of around 70Hz to filter the shunt ...
- 13
0
votes
1
answer
193
views
Inexpensive field deployable non-invasive current sensor [closed]
Is there an inexpensive way to MacGyver a non-invasive current sensor together in a field (yes, a literal field), assuming some prior planning?
The context here is an event similar to EMF Camp or OHM,...
- 11.1k
3
votes
1
answer
1k
views
Automatic ranging current sensing
I am trying to implement a current shunt sensing circuit. This should be automatic and currently i want it to measure uA to around 200mA, and Change to the mA range at around 200uA. This is to profile ...
- 231