Questions tagged [current-sensing]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1 vote
1 answer
28 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=...
user avatar
  • 113
0 votes
1 answer
45 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 ...
user avatar
1 vote
2 answers
74 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 ...
user avatar
  • 579
0 votes
1 answer
39 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 ...
user avatar
0 votes
1 answer
94 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 ...
user avatar
  • 28
0 votes
0 answers
52 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 ...
user avatar
  • 109
1 vote
1 answer
43 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 ...
user avatar
  • 105
0 votes
2 answers
80 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: ...
user avatar
  • 105
0 votes
1 answer
96 views

Sensing current into a battery while charging

I want to sense the current into a 84 V battery while charging and disconnect it when fully charged using a MOSFET. Is it advisable to use lowside current sensing? I used a noninverting opamp ...
user avatar
  • 77
1 vote
2 answers
65 views

AC current detection with 1-10mA sensitivity

I need to build a current switch that will be connected to an Arduino (or Raspberry Pi) digital input. I need it to set to HIGH (3.3 V) if the current is above some threshold, and LOW otherwise. The ...
user avatar
  • 111
0 votes
2 answers
74 views

Voltage divider dropping voltage more than expected

I'm trying to connect an ACS712 current sensor to an ESP32 ADC pin. The ESP32 expects 3.3 V, but the ACS712 can reach 4.5 V. When there's no current going through the ACS712, its signal is 2.5 V, so I ...
user avatar
  • 103
1 vote
4 answers
182 views

Why do I have a sudden current peak when PWMing a valve?

I am driving a proportional solenoid valve with PWM from an MCU as follows: The voltage of the MCU is 3.3 V. The gain of the amplifier is set to 20 V/V. Because the valve consumes 170 mA when fully ...
user avatar
0 votes
2 answers
78 views

Current sense pin detect too quickly (Flyback)

Here is my circuit: simulate this circuit – Schematic created using CircuitLab There is two problems: Firstly, the sense circuit don't open the mosfet at 1V, yet the zener at the V+ in the amp ...
user avatar
  • 73
1 vote
2 answers
67 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, ...
user avatar
  • 3,328
0 votes
1 answer
114 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. ...
user avatar
0 votes
1 answer
26 views

MAX9919 Thermal Pad

I am designing the thermal outline plane of this current amplifier ic in a 4 layer board using Eagle Pro. This board will be made using ENIG process. After spent so much time trying to understand in ...
user avatar
  • 277
2 votes
2 answers
141 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 ...
user avatar
  • 449
1 vote
4 answers
217 views

Sensing voltage drop across the load in the H bridge

I use two BTN7970 to make a full bridge circuit. The load is a piece of shape memory alloy(SMA) wire. I want to accurately measure the net voltage drop on the load excluding caused by mosfet's RDS. ...
user avatar
-1 votes
2 answers
85 views

Why should the fullwave current sensor bandwith be about 10 times switching frequency?

This is an example of high side switch current sensor in a buck-boost converter. I read that for high-side switch full waveform sensing the current sensor bandwith should be about 10 times switching ...
user avatar
  • 1,623
0 votes
1 answer
74 views

Bipolar high-dynamic range current sensing

I'm working on a project that will necessitate bipolar current measurement across a wide current range. It will need to accurately measure current from 750 mA down to 1 nA, although greater. The ...
user avatar
0 votes
1 answer
49 views

Power outage detection to kickstart a safe shutdown and data retention process

I plan a system that operates on a 5v rail. The power is supplied from an outside DC source. The 5 V powers an RPI CM4 and other components that are controlled by it. The whole system requires up to 5 ...
user avatar
  • 65
0 votes
1 answer
87 views

How do you analyze this simple circuit? [closed]

I want to plot Vout vs time graph (which software do you suggest) and also want to find out max and min output voltage (Vout) of the circuit. How can I find the max and min manually? Can I find them ...
user avatar
  • 11
0 votes
2 answers
83 views

non-inverting current sense op amp output unstable during the measurement

I would like some advice on how to solve the following problem. The following circuit is motor driver with current sense circuit. The circuit run motor at cca 30mV when is not under load, but when the ...
user avatar
  • 61
0 votes
2 answers
131 views

Current sensing relay that momentarily closes contact each time state changes

I have a 240V dust collector that I manually switch on and off using a one-button wireless remote. The dust collector is connected to several machines. I'd like to use a current sensing relay to ...
user avatar
0 votes
2 answers
772 views

How to measure very low current by amplifying it?

I am trying to measure current from a DC circuit. So it basically I am trying to make an ammeter. I am using ACS712 20A current sensor and Arduino UNO. Theoretically, I can measure a minimum of 50 mA ...
user avatar
  • 3
7 votes
1 answer
583 views

Can a floating capacitor terminal be used to collect electrons?

I want to collect charge from an electron beam source. For that, I'm proposing to put a floating capacitor with its bottom terminal floating and directly exposed to the electron beam gun. The top ...
user avatar
0 votes
0 answers
35 views

Sensing Ground Faults on a High Voltage Pulser - Coupled Inductor Issue in LTSpice

I am building a ground-fault protected High Voltage Pulser. The pulses may be as high as 500V and as narrow as 50us (20kHz). The question of how to create GFCI protection is proving to be a ...
user avatar
0 votes
1 answer
133 views

Switched Mono jack + battery: Make circuit when plugged in

I would like to replicate the functionality inside the Ampoids guitar amp (9v battery) in which the circuit is turned on only when you plugin a male 6.3mm mono jack to it I believe that the most ...
user avatar
1 vote
1 answer
52 views

Dedicated current sense amplifier vs simp,e difference amplifier

I need to implement low-side current sensing for a H-bridge motor driver. While there are dedicated current sense amplifiers such as TI’s INA180, can I use a simple difference amplifier for this with ...
user avatar
  • 1,280
1 vote
2 answers
59 views

Why most non-invasive current sensors have a minijack at the other end?

If I search on google for non-invasive current sensor and click on the images tab, in most cases, I see a minijack at the other side of the wire. What is the reason for this? Is this minijack supposed ...
user avatar
0 votes
1 answer
177 views

Compact Voltage-Controlled Current Source Array

I'll start by asking what it seems to me a trivial but I don't know what is the most efficient solution. Electronics is not my main occupation, so I may need some indication to proceed: I need to ...
user avatar
0 votes
1 answer
121 views

Adjustable CC/CV supply with voltage and current limiting having no output voltage at low voltage levels?

Im trying to create a power supply with an addjustable output between 0-12V or 0-3A (CV and CC adjustable). To make sure that the components don’t get damaged I'm trying to implement a protection for ...
user avatar
  • 3
0 votes
1 answer
41 views

How to share a current sense pin on a single GPIO

The BTS7040 is a 2 channel High Side Switch with diagnostic feature, im planning on using 2 of the IC and i dont have extra GPIOs to spare. The way you read a fault from the BTS7040 is to select a ...
user avatar
  • 1,734
0 votes
1 answer
55 views

Detect power outage and disconnect heavy loads from the UPS [closed]

I am looking for a simple system to detect power outage and disconnect heavy loads from the UPS backup to maximize the longevity of the power backup. The UPS works on a 24-V battery. The UPS switch ...
user avatar
0 votes
1 answer
900 views

INA219 current sensor not working properly with DC motor

I use INA219 module to read DC motor current for control propose. I connect INA219 in series with motor as shown in schematic. simulate this circuit – Schematic created using CircuitLab The ...
user avatar
  • 1,002
0 votes
1 answer
112 views

Current Sense circuit with digitally programmable gain

I'm designing a precision source meter and I wanted to put a couple ideas out to the community. One thing I will note is that this device has 32 channels, so I need to be very cognizant about both ...
user avatar
0 votes
0 answers
173 views

How to average output of current sensor to get smooth output?

I am using INA138 current sensor with 100Hz, PWM duty 5%, 8-bit resolution signal load is a resistor, I getting zero readings while actual current readings also appear, edited - zero current sense ...
user avatar
  • 184
0 votes
0 answers
41 views

Designing high bandwidth current sensors for inductor current sensing

I am designing a high-frequency current sensor, suitable for sensing +/- 20 Amps at frequencies of 200kHz. This is being used in average current mode control application in an isolated forward ...
user avatar
2 votes
1 answer
136 views

Low Side Current Sensing Grounding Question

I recently made a low side current sense circuit to test a power supply. It works well, but I am trying to understand the strange behavior that happens when I apply the negative lead of my probe to ...
user avatar
  • 147
0 votes
1 answer
332 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 ...
user avatar
  • 3,328
0 votes
2 answers
268 views

Converting a 4-20mA 24V signal to 0-5V?

How do I convert a 4-20mA 24V signal to a 0-5V signal, suitable for A-D conversion with a 5V microprocessor? Can this be done while isolating the 24V from the 5V output?
user avatar
1 vote
0 answers
73 views

Detect Battery Insertion in USB Charging Circuit

I'm using an MCP73831T as the charger IC, I've figured out how to detect the charging/charged, this was easy, however, I would like to know when the battery is actually plugged in, I know when the usb ...
user avatar
1 vote
1 answer
230 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 ...
user avatar
  • 5,776
0 votes
1 answer
39 views

How to sense current AC of a sinusoide -100mA to 100mA with 70kHz

Any suggestions about a chip or PCB component that could work? I tried to use the the current sense transformer PA1005.050NLT https://www.digikey.com/product-detail/en/pulse-electronics-power/PA1005....
user avatar
  • 31
0 votes
1 answer
159 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 ...
user avatar
0 votes
3 answers
504 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 ...
user avatar
0 votes
2 answers
86 views

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 ...
user avatar
4 votes
4 answers
141 views

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 ...
user avatar
  • 245
1 vote
1 answer
187 views

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: ...
user avatar
1 vote
2 answers
103 views

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 ...
user avatar
  • 171