Measurements of the current flowing through a circuit

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Question regarding specifications of power bank for a laptop [migrated]

I'm not sure about how it suits the forum of electronics here on stackexchange, but I hope I'm at the right place. if not, please forgive and explain. So the case is that I own a high-end laptop (...
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2answers
34 views

Doubt about current direction in CircuitLab

I'm not sure how to interpret the current value in this basic schematic. If you simulate it, CircuitLab will plot a value for the current flowing through the Output node. Why is it a negative value? ...
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1answer
35 views

Input and output relation of ACS712 Hall effect current Sensor

ACS712 works by the use of the hall effect principle. When i went through the datasheet, i found out that the relation between input current and output voltage is varied largely ie. 66 mv/A to 185 mv/...
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1answer
65 views

I want to measure the current of a +15/-15 digital signal, non-sine wave

I have a digital signal, similar to RS232, but at +15/-15. It is a non-sine wave and is used to also power DC motors and other devices (address coding, information, and power). I want to measure from ...
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3answers
257 views

Measuring current - shunt resistor or current transducer or something else

I have to measure current which is sine with 37Hz frequency 1350 mA(DC) + 190 mA(AC). The voltage in circuit is generated using PWM 27V, 600 Hz, PWM dithering adds alternating part of current. I want ...
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52 views

Measuring Active power through current sensors

i want to measure the AC current - with 220 V AC 50 HZ at home - i will use a current sensor then find the power factor through comparing the signals of the V and I then find the power then i ...
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2answers
103 views

50A Accurate Current Sensing Circuit Design

I'm trying to design a current sensing circuit that can achieve a 0.01A accuracy across 50A DC. It is a battery powered brushless DC motor drive (battery --> current sensor --> controller --> motor). ...
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31 views

current in circuit in transient state

simulate this circuit – Schematic created using CircuitLab The switch in the circuit is opened at at time t=0. What is the current through 10 ohm and 20 ohm resistor at t=0(-) and also when the ...
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544 views

How I can test the power supply across the load?

I want to test my power supply at the 12 V 10 A specification. I had tried with connect a 100-watt 0.7-ohm load resistor across it, but by that time the voltage went down to 3 to 4 volt. How ...
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46 views

Effect of damping resistor on its upstream?

I am struggling on understanding how certain function of circuit part affect inside whole circuit. There are two electron sources: 1. electrons generated from ionization by discharge (Plasma), 2. ...
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89 views

A basic question on Current Flow, Voltage, and Power consumption

Background: Assume that I have Bulb that consumes 10 watts of electrical energy (power). The operating values for full brightness are: 5 volts, and 2 amps. Since Power(p) = Voltage(V) x Current(I) = ...
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68 views

Current increases when circuit resistance is increased while measuring black box device power consumption

The circuit is powered with 3V a battery and contains a black box device who's power consumption we're measuring with a shunt. The rated required voltage for the device is 3V. Whit a 1 Ohm shunt, the ...
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105 views

Calculating the power supplied by the current and voltage sources

simulate this circuit – Schematic created using CircuitLab I have attended one exam where I was asked to solve this Question. Generally the Power is nothing but the product of current and ...
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2answers
44 views

Current at specific frequencies in a RLC circuit

Having been given a circuit, that has a resistance R of 4.0 Ω, an inductance L of 0.50 H, and a variable capacitance in series supplying a voltage V of 200 V at a frequency fr of 50 Hz, I have ...
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54 views

A DMM low current measurement question

I'm stuck with a question when reading a textbook: The question is a situation as follows: The very high internal resistance of digital multi-meters, in their voltage measuring ranges, can be used ...
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1answer
58 views

ACS712 Low Current Sensor

Before I begin, just to let you know that I'm new to electrical engineering, in case that my question sound weird to you, but here's my problem. I bought few days ago ACS712 Low Current Sensor and ...
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1answer
66 views

How to measure micro and nano amps via microcontroller [closed]

The objective is to build/construct a circuit powered by an ATMEGA32 IC, using C++. This circuit will essentially be an ammeter for small current levels (10-6 and 10-9). I've done some basic points ...
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30 views

By measuring the electricity generated, is it possible to calculate how fast the turbine was moving?

Say a wind turbine is moving at varying speeds. From the electricity it generates, would it be possible to calculate/replicate the motions of the turbine? How accurate can these measurements be? Will ...
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38 views

DS2438 battery monitor: how to connect load

I am looking at the datasheet for the Maxim DS2438 battery monitor and am confused by this circuit diagram: How would the load be connected? If connected between battery + and circuit ground this ...
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1answer
41 views

Resistance measurement using high side current sense amplifier

I want to measure very small resistances (0.5 to 1 Ohm) using a high side current sense amplifier. The device I have in mind is MAX9611. The typical application circuit from datasheet is like: My ...
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1answer
54 views

Common ground between a current source and a power supply

I want to design a simple circuitry for testing a bench top current source through a load resistor. I want to use MAX9611, and read data through I2C by a micro-controller. The rough circuit schematic ...
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2answers
66 views

High voltage DC current measurement by inductance?

I'd like to incorporate a few permanent ammeters in a 600V DC circuit. I've found all sorts of nifty panel ammeters, both analog and digital, but most are rated to less than a tenth that voltage. I ...
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43 views

MPPT using pic16f877a (solar battery charger)

I'm trying to charge some batteries using 12v solar panels. I'm using a pic16f877a for the mppt algorithm(incremental conductance). I have two problems: 1)Current Sensing: I want to use acs712 (5A) ...
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101 views

determining current in individual phase for a 3 phase winding brushless dc motor

I have an 3 phase brushless dc motor with no neutral wire. I measured the resistance from phase to phase and found them to be on average 0.255 ohms(between A and B, A and C, etc...all the values are ...
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4answers
151 views

Low-side current sensing

I'm trying to build a brushless dc motor driver, which provides the possibility to measure the currents on all three phases of the motor independently. The driver IC that I'm using (DRV8313) has three ...
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1answer
41 views

AC power measurement query

I'm trying to understand and tweak this smartplug reference design from TI. I'm stumped on the Metrology Analog Filters section on page 1. What I do not understand is why is there a 0R resistor on the ...
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42 views

Measure current in power suppy [closed]

I have a power supply which I ordered online for 100 amps. I thought it will be digital but its an old fashioned type. I want to build the current sensing circuit to find out how much current is ...
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1answer
81 views

Measuring DC current with Hall Effect sensor over PIC on the same circuit

Before I begin with my question just so you know I'm not very familiar with electrical engineering so please forgive if I ask some dumb question :) What I want is to know if I can use Hall Effect ...
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73 views

practical design of integrator circuit with Rogowski coil

I am designing a current sensing device, using a rogowski coil.To give a simple explanation of the Rogowski coil, if I were to disregard parasitic components L2, R1, C1 and R2 the output voltage would ...
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1answer
45 views

Why is bi-directional current sensing required in sensorless BLDC field-oriented-control?

For the past few weeks I've been trying to understand Field-oriented-control for 3-phase motors. Eventually I would like to implement one. I've gone through dozens of application notes from Microchip, ...
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1answer
36 views

Current Transformer properties

I have a mains track (230VAC, 50Hz) on a custom PCB routed to multiple Solid-State Relays, and I want to measure the power going through this line. I'm looking into Current Transformers (CTs) to ...
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52 views

How to measure 3phase RMS currents in PSCAD

I would like to measure 3 phase rms current as well as voltage of a load, In PSCAD 3ph rms voltage measuring block is available but there is no such block for current.
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71 views

FET Current limiter 30A and overload detection

I plan to make a module for my motorbike to replace fuse by current limiters and overload detection system. I've heard nice things to do with J-FET. It should work up to 12V 30AMP. The detection ...
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163 views

How to make ammeter with arduino?

i'm interested to make ammeter from arduino. So, i have 70A/50mV shunt resistor and wiring it into arduino. From my schematic, Is this possible to meassure the current from 12V battery?If it possible ...
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83 views

ADC error for low-voltage measurements

The application is high-side current sensing for a battery-operated device. The current drawn from the battery goes through a shunt resistor, the voltage across the resistor is amplified by an INA, ...
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41 views

Effects of introducing offset in a current sense amplifier

I am working with the MAX9643 current sense amplifier in a configuration similar to this. I need to introduce a small offset in the output voltage. What are my options of doing this? Can I directly ...
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210 views

Current sensing at μA accuracy and ADC nonlinearity

Project context A battery-operated positioning device sends location information through GSM at regular intervals. Between the fixes, the device is in low-power mode. The battery is supposed to last ...
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38 views

High voltage reading isssue

Here i am attaching old and new schematic for reference.While designing the old board i have made mistake keeping HV- (j14) as common ground reference . J14 and j12 are connected with high voltage 0-...
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33 views

Current in a galvanic cell

I was looking through chemistry textbooks to find out how to determine how much current a galvanic cell should generate and what affects that current value. However, I did not find anything: textbooks ...
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73 views

What type of fuse should I use for this basic electronics design?

I'm creating a simple Arduino project that utilizes a solenoid and a rotary encoder. I'm powering the entire device with a 12V 5A switching power supply. I want to add a fuse to the design but can't ...
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59 views

why is the current of a aluminum-hydrogen galvanic cell low

I am having a galvanic cell with the following half cell equations: Anode--> 2Al(s) + 6OH --> 2Al(OH)3 + 6e- Cathode--> 6H+ + 6e- --> 3H2(g) I connected my cell to a 47 ohm resistor and measured ...
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47 views

measuring a bad motor and large current spikes in a brush motor [closed]

I am new to this forum, I am an EIT and I have been tasked to implement a fixture to measure high current spikes on brush motors when loaded and unloaded. I am at a loss here as I have never ...
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1answer
45 views

Rogowski coil with magnetic core

is it possible to use a rogowski coil with a magnetic core? ie i want to integrate the output of such coil rather to place a resistor on it. so, what is the differences between it and a current ...
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53 views

What does the values or details mean? [duplicate]

You can see some values on all electronic devices like 5V,0.2/0.3A on mobile chargers.What do these values represent?what can we understand from them
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1answer
129 views

Piezoelectric Voltage and current measurement across a 3.3kohm resistor.

I am testing a PZT 43 material with tapping sequence. The measurement of the material is: 10mm in length and 0.8CM in diameter. I am tapping the material with a plastic and holding it down with a ...
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1answer
46 views

DC Fan using less than half of rated current. Looking to overvolt

I have a project involving a 200mm 12VDC PC cooling fan (FS-200RB) that will be used for cooling me - not a computer. The fan is labeled: 12V DC / 0.42A / 5.04W ...
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14 views

current of a galvanic cell

I am having a galvanic cell with the following half cell equations: Anode--> 2Al(s) + 6OH --> 2Al(OH)3 + 6e- Cathode--> 6H+ + 6e- --> 3H2(g) So my cell is producing 6 electrons. Is there a way to ...
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1answer
133 views

How to measure supply currents ranging from 1μA to 10mA?

I’m building a battery powered data logger with a microcontroller and several sensors. I’d like to measure the supply current of individual parts with idle currents in the μA range and peak currents ...
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58 views

how to measure current of a galvanic cell with a voltmeter

I was wondering how I could measure the current generated by my galvanic cell: can I just directly connect my voltmeter to the two electrodes of my cell, or do I have to put it in series?
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106 views

Current limit using MOSFET

I am driving a 24V DC Motor which can draw up to 30A and I would like to incorporate some over current/short circuit protection. As such I am planning to place a shunt resistor and power MOSFET(...