Questions tagged [current-sensing]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
0 answers
46 views

Current-sense resistor switching mechanism

I planned to make a DIY power meter with automatic switch for current range, usually towards low (uA maybe) currents. I came up with the design below to switch between various current-sense resistors. ...
Tirdad Sadri Nejad's user avatar
1 vote
1 answer
78 views

Choosing an adequate op-amp for shunt resistor sensing in SMPS applications

I would like to get some industry experts / design engineers opinion about potential methods to improve the proposed shunt resistor current sensing method below. The intention is to improve this ...
rbe's user avatar
  • 23
2 votes
1 answer
128 views

Understanding current sense circuit

I'm trying to adapt a current limiter design that I found, and I'm having trouble understanding the "current sense" part of it. The current sensing is implemented using a shunt resistor, ...
Malte's user avatar
  • 145
1 vote
3 answers
164 views

High-side current sensing using PNP

I have the following three states: State 1: When system is active with transducers, current through the load is approximately 350 mA. State 2: When system is activated without transducers, current ...
user101095's user avatar
2 votes
1 answer
105 views

How to sense a varying current and voltage without affecting the load

I've been asked to build a circuit to switch a constant power (varying current & voltage) supply between two loads, for a research experiment the customer is carrying out. The loads are unknown ...
Joe Mills's user avatar
0 votes
2 answers
61 views

Designing a current sensing op-amp circuit for an AC load

I'm trying to simulate a current sensing op-amp circuit. My AC voltage, 24 VAC, is across a load of 10 Ω. I used a 100 μΩ resistor and measured the voltage across it using an op-amp. Looking at some ...
Bilal's user avatar
  • 1
0 votes
2 answers
69 views

Flyback converter sense resistor placement and wiring

I am designing my first ever Flyback converter. The Fsw = 100kHz. Peak primary current = 3.26A. The converter has to fit in a very small space, so I'm making a lot of compromises. For example, I could ...
slimcolt's user avatar
  • 123
1 vote
2 answers
48 views

Issue with influence between channels in a dual-channel high-side current sensing circuit

I've designed a two-channel current sensing circuit integrated into a board that outputs two separate signals. However, I'm encountering an issue where one channel seems to influence the other, which, ...
Bongjin's user avatar
  • 15
0 votes
2 answers
96 views

Is there a reliable way to sense RPM without modifying a spark plug cable?

I need to recreate a tachometer without altering the wire that goes to the engine spark plug. I can only modify the wiring intended to close the circuit to turn off the engine. It is necessary to take ...
JB-GB's user avatar
  • 1
6 votes
1 answer
481 views

Is it wise to determine heating element temperature from resistivity?

Context I'm making an electric furnace for melting metal, and aiming to make my own controller. Everyone seems to just use thermocouples and a control loop, I thought perhaps I could just measure the ...
TrisT's user avatar
  • 355
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 ...
JYelton's user avatar
  • 33.9k
1 vote
1 answer
85 views

Need to understand the current sensor connection in this circuit

I'm working on creating a smart power meter for my home, and I found this tutorial. I want to understand each part of the circuit, and the tutorial covers everything. However, it doesn't explain why ...
M-125's user avatar
  • 53
1 vote
2 answers
94 views

Input Filter for Current Sense Amplifier - ODrive

Out of curiosity, can anyone explain to me why the input filters for the current sense amplifiers in the old ODrive schematics are unbalanced (i.e., the external resistor is only on the negative CSA ...
Murphy's user avatar
  • 11
1 vote
0 answers
94 views

Designing Eddy Current Sensor?

I am looking to build a eddy current sensor, I am having difficulty finding information on how I should be designing the sensor to fit my needs. There's a few studies and articles I've found that ...
Mark's user avatar
  • 11
0 votes
0 answers
136 views

Valid usage of OpAmp for current sensing with motor driver

I am working on a custom PCB that can perform position control using 3 DC motors. One of the functionalities that I am trying to implement is stall detection and current limiting. I closely followed ...
Stathis's user avatar
  • 33
0 votes
0 answers
54 views

How do I make the circuit to sense the collector current for the FAN1100-F085?

I am trying to design an ignition coil driver using the FAN1100-F085 IC and a ISL9V3040x3ST−F085C IGBT. I am having trouble understanding the datasheet when it comes to the current sensing. It says to ...
Struner's user avatar
8 votes
3 answers
2k views

How is this a current mirror?

This article is talking about floating an IC's GND to use it at a common mode voltage higher than it is rated for. It then says it level shifts the IC's current output to ground by using the Q1-Q2 ...
TotesMyGoats's user avatar
2 votes
1 answer
224 views

Current Transformer Current Sensing via operational-amplifier

This is a current sensing circuit, L1(CT2320) is a current transformer, U1 is generated by IGBT inverter ,U is one of a three phase of the motor driver voltage. I have several questions about this ...
Jason Haynes's user avatar
0 votes
0 answers
34 views

SCR falsely triggered on startup (battery low current monitor)

I'm trying to build a li ion low charge current detector and cutoff circuit as a complement to my battery charging setup. Charging should be disconnected when the current reaches 400mA or below. I'...
Buck8pe's user avatar
  • 1,684
0 votes
2 answers
73 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 ...
ZACK's user avatar
  • 3
0 votes
1 answer
240 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 ...
Zhi's user avatar
  • 29
1 vote
2 answers
75 views

Is amplification needed for high-side current sensing?

I have a 5 V system and I want to monitor the current in different parts of the system. I am planning to place a small value resistor on the positive power rail and feed the rail voltage and the ...
HV16's user avatar
  • 305
3 votes
1 answer
157 views

Current detector transformer on optocoupler

I need a current detector that outputs a logic signal (1 or 0). I DON'T need to measure current. Detected current: AC. Voltage: 220V. Load power: ~1kW. FOR EXAMPLE: I need a current detector that ...
Mia's user avatar
  • 33
1 vote
1 answer
52 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 ...
Martel's user avatar
  • 1,239
1 vote
0 answers
143 views

Removing the effects of Parasitic Inductance in current sense resistor – Low side current sensing

We are evaluating MIC21LV32 from microchip in one of our applications. For the current sensing we have used 3 mΩ sense resistor (1206, 1 %, 1 W), as these sense resistors have higher ESL+ parasitic ...
user19579's user avatar
  • 1,388
2 votes
1 answer
151 views

LEM current transducer 2.5 V internal reference

I am testing a LEM LTSR-25-NP current transducer. According to the datasheet, the current transducer should be outputting 2.5 V +/- 0.025 V when the input current is 0 A, but this is not what I am ...
Luis's user avatar
  • 41
1 vote
0 answers
71 views

AC Current Sensing LED indicator circuit

I'm playing around with a circuit to drive a LED based on the output from a current sensing transformer. The idea is to have the LED appear proportionally brighter with the output from the current ...
CatalinM's user avatar
  • 387
2 votes
3 answers
337 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. ...
Karthick selva's user avatar
0 votes
1 answer
62 views

Best approach for using multiple power monitors with single MCU (SPI)

I'm working on a project where I'm using several buck converters controlled by the same MCU (ESP32) and I will be adding a digital Power monitor to each converter. but I'm concerned about the number ...
Bananabread's user avatar
2 votes
1 answer
153 views

Current sensing resistor placement [closed]

I will be adding a current sensing resistor to a Buck-boost DC-DC converter. Based on the IC datasheet, the resistor is placed at the low-voltage side next to the power inductor. But, as far as I know,...
Bananabread's user avatar
0 votes
1 answer
193 views

Inrush current on current sense resistors

The problem is on a circuit which implements PFC circuitry. There are two parallel 0.36R current sense resistors located in the inrush current path. These resistors measure the PFC current through the ...
ohkann_'s user avatar
0 votes
0 answers
129 views

Current Sensing Trace Routing

I'm developing a motor control board (sensorless FOC). I have a question about the differential pair traces, they are very long (the longest is about 80 mm) and crosses several gate lines. How bad is ...
Daniel Müller's user avatar
-2 votes
1 answer
61 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 ...
Aman Goyal's user avatar
1 vote
2 answers
394 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 ...
Karthick selva's user avatar
0 votes
0 answers
70 views

Self powered current sense in tapped inductor buck converter

I am interested in designing the autonomous (both turn on and off) high-side high-voltage switch proposed in this paper. The proposed topology of the high-side switch is as follow: Auto-turning on is ...
hiak's user avatar
  • 95
0 votes
0 answers
57 views

How to sense the current an amplifier is supplying?

Consider the circuit below. It is made up of three parts: input, bidirectional amplifier, and output. If we set the gain of the amplifier to 1, then it as if we've just connected the input to the ...
Leonhard Euler's user avatar
0 votes
0 answers
80 views

Choosing the kind of current sensing method and the voltage of the testing signal for a DIY LCR meter

I have been designing my own LCR meter that uses the V-I method to make measurements. I have finished the sine wave generator and processor side, but I got stuck at the sensing part. Here I have 3 ...
bstech's user avatar
  • 1
2 votes
4 answers
514 views

Unexpected behaviour of current sensing circuit with op-amp

I would like to use the schematic below to measure the output current of a buck converter (0-10 A) and convert it to a voltage of 0-3.3 V which is read by a microcontroller. During startup I sometimes ...
emdura's user avatar
  • 41
2 votes
2 answers
851 views

Can a non-invasive AC current sensor measure DC current? [closed]

Can a non-invasive AC current sensor measure DC current? What is the theory behind it?
GYNB's user avatar
  • 31
0 votes
0 answers
108 views

Help understanding conflicting results from INA190 current sense amp

Built a board for a drone that has a few things onboard, though the one that is messing me up is the current sense chip, INA190, though it's most likely not the problem. Picture 1 show the big yellow ...
Sean's user avatar
  • 1
0 votes
2 answers
219 views

Sensing presence of 220 Vac for MCU

I'd like to use an HCPL3700(M) (datasheet) to sense if a 220 Vac mains is present. In my application, the device needs to raise an alarm if the mains voltage is lost. Backup power will be provided by ...
Michael Larsen's user avatar
2 votes
3 answers
658 views

3-phase inverter low side current sense

The setup I'm currently doing some experimentation with 3-phase inverters for BLDC motors and current sense. I have at hand this board featuring: IR2103 MOSFET driver. LIN# inputs are connected to ...
Guido Bocchieri's user avatar
1 vote
1 answer
146 views

How to select current sense resistors for ir2136 ITRIP signal

Looking at the datasheet of the IR2136 it suggests this little resistor network as input for the ITRIP pin. https://www.infineon.com/dgdl/Infineon-IR213-DS-v01_00-EN.pdf?fileId=...
Fabian's user avatar
  • 113
0 votes
1 answer
97 views

Some questions regarding measuring current using ACS712

I'm using an ACS712 0-5A current sensor to measure the input current to a boost converter for the implementation of MPPT algorithm. To do so, I need to connect the ACS712 chip in series with a PV ...
Narutorunner11's user avatar
1 vote
2 answers
90 views

How critical is the sense resistor?

In the following topology, two 0.68 ohm resistors are paralleled to result in 0.34 ohm for sensing the source current. Can I use three paralleled 1 ohm resistors to result in 0.333 ohm? Does this ...
WeTech's user avatar
  • 735
0 votes
1 answer
174 views

Differential current sensor probe- Ground leakage current measurement probe for oscilloscope

I would like to know what you use to measure differential current which is also leakage current sensing. Background: In industry , the AC or DC current flowing from inverter/ converter needs to have ...
Power_Electronics's user avatar
0 votes
1 answer
229 views

Most accurate way to measure universal (AC) motor current?

I'm designing a control circuit for a universal (AC) motor (single phase, brushed). I've simulated the control circuit and it works as expected. Circuit below is controlled by a STM32G4 series ...
David's user avatar
  • 28
0 votes
0 answers
236 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 ...
T.S's user avatar
  • 107
1 vote
1 answer
180 views

Unexpected output with INA138 current sensor

I have no experience with current sensing ICs and I'm trying to build a current sensor with an INA138 IC that I've imported into LTspice. From the manufacturer's website, I'm expecting my output to ...
p.chives's user avatar
  • 105
0 votes
2 answers
141 views

Designing a high-side current sensor

I'm trying to design a high-side current sensor for limiting the current in a circuit I'm building however I'm very inexperienced with the operation of high-side current sensors. This is my circuit: ...
p.chives's user avatar
  • 105