Questions tagged [current-sensing]
The current-sensing tag has no usage guidance.
180 questions
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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 ...
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2
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I am looking for a 40 input OR gate which minimize PCB space
I am using 40x ICs INA301 to measure overcurrent in 40 interfaces
Finally I want to have 1 single "output" to signal if there is an overcurrent in ANY of the 40 interfaces
I don't want to utilize any ...
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4
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248
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Charge indicator with comparator - very sensitive to noise
I need an indicator when the current from my charger is larger than 100mA. I tried the below circuit but this seems very sensitivity to noise. Probably I am getting some ripple in the mV range from ...
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Reading registers from ACS71020 over SPI
I'm trying to read registers from current-sensing chip ACS71020 connected over SPI.
This is how I initialize the SPI:
...
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AC phase current sensing using Isolated delta-sigma modulator
I am trying to design a isolated AC current sensor.
I've chosen the AMC1106 Isolated Delta-Sigma Modulator.
(change my mind if you think there is a better solution for 220V AC; 2A Max; 0.25%)
The ...
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Load sensing relay/power switch/adapter which switches on when it detects some load on its input
Complete newbie here. I'm not using the right terms, so my apologies in advance.
The problem is simple. I want my powered computer speakers (2.1) to turn off when the computer is turned off. I have ...
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48
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Method for sensing fault currents with microcontroller
How do I choose a proper approach for detecting ground fault currents (20 mA through 30A, 60Hz)? Let's say I have a zero sequence CT and calculate a burden resistor. I have a 12-bit ADC in the micro. ...
user115094
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223
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Measuring AC Current at High Voltages (up to 600VAC)
I've been looking at various ways to measure current for a while now, and am stumped on how to read high-side AC Current Measurements ohmically (no Hall Effect sensors). My initial thought was to use ...
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288
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op-amp level shifter
I'm working on a brushed dc motor driver and I have to monitor the current. so I use ACHS-7121 current sensor. This sensor convert +-10A into 0V to +5V and have +2.5V in zero current.
Now I want to ...
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2
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Current Sensing with Op-Amp, do I need a shunt resistor in series with the load on the output?
Hi I am building a circuit to measure current draw from a load, I opted for a voltage follower with a transistor and a shunt in between, The transistor is needed to allow higher currents to flow ...
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725
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Current sensing relay with delay on break for dust collection system
I am in the process of planning our a new workshop in a single car garage. I have a large 20A Dust Collector that needs to be on its own circuit or else it will trip. I also have a ceiling mounted ...
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2k
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Detecting switch closure
Any techniques/circuits/sensors that can determine the open/closed state of a set of contacts, independently of whatever power or signals are being switched by the contacts?
Obviously easy if there's ...
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Output current and voltage levels regulation in ac/dc adapter
On the picture below is the output circuit of AC/DC adapter. I understand how voltage level contol works, but I don't understand how exactly current limitation works and how should I calculate ...
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695
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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 ...
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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 ...
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Measuring high currents with toroids
I got a PT27312 current sensor (datasheet), I wonder if I can use it to measure currents up to 100A AC/DC.
I couldn't find any specifications in respect of the current measurement range.
I only know ...
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511
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Working Voltage for Basic/Reinforced Isolation (ACS712)
I'm planing to use current sense chip ACS712.
I don't understand some values in its datasheet, page 2 (Isolation Characteristics).
I understand "Dielectric Strength Test Voltage - 2100VAC" - that ...
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"ground disturbance" in current sensing with shunt resistor
There are lots of questions about "traditional" low-side current sensing using a shunt resistor.
Most discussions and papers mention the drawback of "ground disturbance" introduced by the measurement ...
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XADC Current Sensing Reference Design
Please refer to this reference design for AC701 (snippet below).
The schematics, specifically the current sensing sections in pages 34-36, show this:
I want to understand why, for the REF output of ...
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2k
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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 ...
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What is negative current?
I understand that voltage is relative to ground, so that can be negative.
However, I'm currently looking at current-sensors (ACS712 current sensor) and in the performance characteristics table, it ...
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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 ...
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Current sensing using XADC
AC701 Schematics
Refer page 40 of the schematics. Here for Vccint- the regulator is switching at 250 kHz.
page 34 has the sensing signal conditioning for that the inst. amp used is INA333 which ...
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Current Sensing Amplifier Circuit explained
I've been trying to understand why each every comment is in the circuit shown. I understand that the amp is taking the voltage drop across the Rsense and amplifying it such that the current across it ...
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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 ...
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Sensing Voltage and Current of an Adjustable Voltage Source
I am currently working on an Adjustable Voltage Source, the Voltage Source is built by a voltage regulator with an OpAmp with and a Darlington transistor for current amplifying as the following ...
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462
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Current sense trace vias underneath shunt resistor
I need to connect current sense traces from a shunt resistor to my PMIC on the other side of the board. Due to space constraints, I'd like the traces to pass through vias directly underneath the shunt ...
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2000A current sensing using STM32
Is there any chance to read 2000A using STM32? I searched the Internet for low-value shunt resistor but nothing found. maybe some kind of current transformer could do the job!!
any help will be ...
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Buck converter design using MCP1630V
I have already designed a buck converter with the following specifications using an MCP19035:
Vin=14V,
Vout=1.8V,
Fc=63kHz(Crossover frequency),
Vref=0.6V,
Iout=10A
step load High IOH=7.5A
step ...
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Using a switching DC-DC converter in high dynamic range current/voltage sensing
I'm thinking of making a power meter circuit which will have a high-side current-sensing amp (LTC6102), a resistive voltage divider for sensing the voltage, a dual op-amp (OPA2365) as a buffer for the ...
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H-Bridge Low Side Sense Resistor - Position of Resistor and Bulk Capacitance
My question regards the considerations required in determining the location of a current sense resistor on the low-side of an H-Bridge. I've presented two scenarios.
Details: The H-Bridge load is a ...
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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 ...
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FOC sensor vs sensorless
I am trying to understand the hardware difference between the sensored and sensorless FOC 3-phase Induction Motor Drive circuit.
So far what I understand is that FOC require following sensors:
1. ...
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387
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SMPS Current Sense Resistor Selection
I am looking into using an SPV1040 boost converter to charge a battery from a solar cell. The chip includes inputs for a current sense resistor, which are described in one of ST's applications notes ...
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Shunt resistors and PCB layout
I have several questions about the current sensing through a resistance.
The resistances are 2-SMD package and I will use the 4-wire kelvin method for the layout.(see image) Specifically, there are ...
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Current sensing for side channel analysis
I'm trying to design a power supply with a built in current sensor for a digital system. The purpose is for side channel analysis. In current sensing, I would like to detect both the AC and DC current....
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Over-current sense
I am using a circuit shown below.
it is designed to sense 1.5 A whenever the load takes current >= 1.5 A. Rsen senses the related voltage and activates the transistor.
Here I use a Rsen = 0.46 R(0.7V/...
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Four-terminal resistor pinout?
Anyone can tell me (or preferably, point me to a source that explicitly shows) the pinout of the 4-pin current-sense resistors?
I'm seeing the datasheets for three different models (including Rideon'...
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Current sensing on negative 1.1kV DC rail
I searching for a way to do high side current sensing on a -1100V DC rail.
My HV is generated from the hamamatsu C9619 High voltage power supply module and it powers the hamamatsu R647P ...
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High side current sensing for negative high voltage
I need to monitor the current for a negative high voltage supply.
I implemented the following circuit in a simulation program:
https://www.maximintegrated.com/en/app-notes/index.mvp/id/1867
But ...
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412
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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 ...
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High voltage 1100 V current sense on the high side
I have the circuit that you see below.
My load is a photomultiplier tube equivalent to a 3.63Mohm resistor.
My power supply can deliver max 4W (2kV and 2mA). I use it on 1100V and the load draws ~...
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Noise problems in current sensing
I have the following circuit:
simulate this circuit – Schematic created using CircuitLab
I am using a motor from an electric bike, as a generator and I am rotating it using a drill, to test ...
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Low side current sensing
I’m making a BLDC motor controller application. The motor control IC (Allegro A4931) uses low side current sensing (R7,R8,R9) for controlling the motor. Unfortunately the motor IC does not output a ...
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763
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Placement of sense resistor on DC-DC converter
For my design I am using DC-DC converters LTM4620 and LTM4644, which integrate the MOSFETs and the inductor in the chip.
For measuring the output current, I will add a sense resistor in each output ...
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Problem simulating LMP8645 current sense amplfiier in LTspice
Basically the problem i am getting is that the output offset voltage is extremely large (58mv)
here is the datasheet for the amp: http://www.ti.com/lit/ds/symlink/lmp8645hv.pdf
on page 9 it shows ...
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How to measure DC current with a microcontroller?
I have a project where I need to measure DC currents in the range of 0-150 A. I am using an STM32F446RE MCU. I can't use the solution where I convert current to voltage using resistors and reading ...
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972
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high side vs low side current sensing in isolated bench power supplies, does it matter?
I'm trying to make a couple of mains isolated, transformer based, bench power supplies. Considering that the current sense resistor will be in the PSU box and external loads will not have access to ...
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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 ...
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