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Questions tagged [current-measurement]

Measurements of the current flowing through a circuit

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29 views

How can i use ACS712 to detect AC voltage variation?

I have a current sensor IC(ACS712) and try to create a capacitor combination as shown . is it possible to detect the ac voltage variation using this ic? i am tested ones but i got result a constant dc ...
0
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3answers
62 views

How Much Current is Usually Used with IR Transmitting LEDs, in Remote Controls?

If you take various Remote Controls from your home, such as for a TV, Audio System, TV Box, etc, and measure the current that is supplied to the IR LED in the remote, what would be common current ...
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1answer
62 views

Resistor values on a 12v 10a circuit with LT3045 LDO

I am currently working on a project that aims to provide 12v 10a in the final output. I am quite new to EE and wasn't quite sure if I have choose the correct resistors value as highlighted in the ...
0
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1answer
41 views

Correct way to ground components for solar panel measurement

I'm currently doing a project where I'm supposed to measure the current and the voltage from a solar panel and am unsure of how I should ground all the components in the circuit (since electrical ...
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2answers
93 views

Oscilloscope range affecting voltage reading

I am trying to measure the current usage of a device using an oscilloscope. Every second the device turns on for a few milliseconds and then goes back to sleep. I need to find how much current is ...
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1answer
72 views

Current sensing techniques in SMPS

I have gone through the following circuit provided by microchip technology and I get trouble in understanding the circuit circled in red the the image!! As I understood, this circuit is used as a ...
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5answers
136 views

How can a multimeter measure current while being parallel to the element

An ammeter is a low resistance device connected in series with the element through which we want to measure current However, a multimeter is connected in parallel with the element under observation ...
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1answer
55 views

Fast 5V DC power monitoring

I am designing a camera that is powered by a 5 V DC power line. I need to evaluate the peak power consumption of the device during image capture. At a pixel clock period of 40 microseconds I expect ...
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1answer
35 views

Help understanding amperage of DC motor and heat generation

I am diagnosing an issue in an automotive HVAC system and have been testing the blower motor. I would expect somewhere approximately 8A to 15A of current draw. I have test wired the motor with 14AWG ...
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0answers
66 views

Measuring a small distance via capacitance

I am interested in measuring a small \$d\$ between two objects shown below by measuring the capacitance between the Terminals denoted as T0 and T1: The distance \$d\$ is roughly 1mm +/- 0.5mm ...
1
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1answer
39 views

Why ACS712 is abruptly dropping its voltage output?

I have built a board as shown in the images and the schematic below. I know that according to the datasheet when no current is flowing through the ACS712 it should output something around 2.5V always. ...
2
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1answer
54 views

Measuring integrated current

I want to measure the amount of light striking a photodiode in a specific time window (about 1ms). In this window, we get \$10^6-10^7\$ photons, which get converted into electrons with about 80% ...
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1answer
96 views

DC Current Measurement (resolution of ~ 1 uA)

I haven't worked with electronics in a long time, and now have the task of measuring the power consumption of a low-power device I'm writing firmware for... When the device is drawing very little ...
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1answer
47 views

Does a common neutral between solar inverter and utility affect current measurement?

I have solar hybrid inverter at home that's connected to the mains using both, the line and neutral wires. However, to save the costs, I've connected the load to it using a common neutral i.e. I've ...
6
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3answers
579 views

Current sense amplifier + op-amp buffer + ADC: Measuring down to 0 with a single supply

I'm thinking about current sensing with a high dynamic range (10 mA - 20 A) and using LTC6102 as a high-side current sense amp (the voltage would be 54.6 V max, a 13S6P Li-ion battery). ...
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2answers
57 views

Measuring Power across a dummy load - use voltage or current?

I have a high power 8Ω resistor dummy load (approximating a speaker) which is being driven from the output of an audio amplifier. I want to measure the power consumption and display the results on an ...
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0answers
53 views

Detecting both short and open circuit voice coils in coil driver

I'm building a voice coil driver for a science experiment. The coils are in an environment where both coil shorts and coil open circuits are common problems. I'd like to build in a fault indicator to ...
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0answers
79 views

Capacitor in the circuit - Bypass capacitor

I was trying to measure the supply current of a CAN transceiver during fault conditions, one thing which I noticed was that during CANH to GND(when the current consumption is supposed to be the ...
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0answers
43 views

Measure low AC Power consumption (oscilloscope? MCU?)

I would like to measure AC power consumption of devices such as AC/DC charger, AC LED bulb or an electric circuit in the main box of a house. However, their power consumption are quite low and the ...
0
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2answers
113 views

Circuitry to measure sub-nano ampere current [duplicate]

Is there a well known methodology to design a IC circuitry to measure sub-nano ampere or even pico ampere currents within a very short delay of nano seconds? The SNR could be assumed to be fairly good ...
3
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4answers
130 views

How to measure micro watts (uW) [duplicate]

In an extreme low power project (MCU+BLE SIP running on a CR2016 battery for year(s)) I would like to measure the power consumption under different environments/algorithms. What would be the correct ...
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0answers
51 views

20 kV 100 mA Voltage Current Sensor

like the title says, i need to measure 20 kV 100 mA line. For the voltage part i found this:http://www.koncar-mjt.hr/en/docs/koncarmjtEN/documents/61/1_0/Original.pdf and this:https://www.hivolt.de/...
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2answers
29 views

Use of UC3843BD1G for current measurement

I was trying to develop an accurate current measuring circuit. So I opened up a multimeter for some reference. In which I found this UC3843BD1G Current Mode PWM Controller. Can this chip help me in ...
3
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2answers
1k views

Current measurement op-amp calculation

I am trying to measure the current using sense resistor method. Low Side Current Sensing method: I am using shunt resistor in the low side, there will be a voltage drop across the resistor. Since ...
0
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1answer
88 views

5V Current Transducer to 3.3V Analog GPIO Input

I am trying to find 3.3V variant of the 5V Current Transducer LTS_25-NP but so far no success. Is it possible to interface this 5V analog output to 3.3V STM32F407 analog input GPIOs? Edit: I want to ...
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1answer
222 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 ...
0
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2answers
53 views

Selection of External Current Transformer

simulate this circuit – Schematic created using CircuitLab I am designing a product for motor protection circuit. where I want to use customized external CT for application which gives me ...
0
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1answer
68 views

What will be the current flows through the following circuit?

I`m confusing to see a textbook there is no current flows through the 7 ohm resistor. But why? And what will be the total current flowing through the circuit?
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1answer
28 views

High Power DC motor current control

I need to monitor a high power DC motor with 48V and 600A battery, if it's stalled or not (its a lift truck). The driver is 25 parallel MOSFET with Rds(on)=7.6e-47 which control by 15kHz PWM. I think ...
4
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2answers
589 views

Digital Current limiting with MCU

All current limiting circuits I've found until now use some sort of analog Logic with Op-Amps to limit/control the current. (Why) is no digital current limiting used? I would imagine a shunt resistor ...
0
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1answer
102 views

Voltage drop - Diode reverse biased

Can you please help me with this exercise? In each circuit, calculate the current flowing through the 10kΩ resistor and calculate the voltage drop across the germanium diode. Please assume that a ...
2
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1answer
99 views

Significant DC current on precision DMM despite not being connected to anything

Disclaimer: I'm not a EE professional (I have a background in physics though), so please bear with me if the question seems banal, obvious or just plain stupid. We have a Keysight 34465A DMM, which, ...
0
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3answers
56 views

Power determination for resistive load

I am a mechanical engineering student and i need to measure electrical output. I have some voltage and current measuring instruments. I used them to measure the voltage & current of a blower(...
0
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2answers
56 views

CB blew when trying to measure the current using multi meter. What went wrong?

I set my multimeter like this. Plug the black lead to the short tab of NEMA5-15 receptacle first and the red lead to the long tab. The moment I put the red lead in, there was a big spark. The ...
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0answers
60 views

Measuring current in the case of bridge amplifier at several MHz

Is there a way (or some chip) to measure current at about 5 MHz when the bridge amplifier is used? The output is a sine with amplitude 15 V. I need to measure accurately both amplitude and phase (the ...
0
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1answer
45 views

How to measure current on low voltage/current brushed motor driven by H-Bridge?

I have a gearbox which transforms the rotational movement to linear movement. It drives a pin which moves back and forward using a DC motor. I need to know when the pin reaches the two "end-stops" (...
0
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3answers
102 views

how to avoid brownout caused by a multimeter on esp32

I am using the VOLTCRAFT VC130 multimeter for measurement of current through my esp32. The microcontroller runs perfectly with two 1.5V batteries(~3V as read by multimeter in voltage mode). But when I ...
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3answers
72 views

digital current monitor/sensor for monitoring ~0.1 uA to mA current from a MCU and sensor [closed]

Hello I am in need of a current monitor/sensor like INA219 for monitoring current in the range of 0.1 uA to ~ mA. Kindly suggest a way to monitor current in such lower range. I have a microcontroller ...
0
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1answer
68 views

How can I find the short circuit current across a and b?

In order to find R thevenin, I need to find Isc across a and b since there's a dependent source. Based on my calculations, Vth=500/3V. I've spent countless hours thinking about Isc,please help.
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3answers
379 views

Stall current calculation for DC motor

I'm trying to calculate the stall current for a 12 V DC gear motor (919D1481): No load speed = 15800 RPM No load current = 0.52 A Nominal speed = 13360 RPM Nominal current = 2.85 A ...
0
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1answer
44 views

How to measure small AC mains currents from a microcontroller?

I'd like to build a battery charger control circuit using an Arudino, a relay module, and a current sensor. I'd use the relay to turn on AC power to a "smart charger" for one or more sets of lithium ...
0
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1answer
61 views

CT measuring circuit with PIC

I am using external CT to measure Current parameter. I am using PIC16F1938 to measure analog . Now here i am looking for circuit and calculation involved to get proper current rating datasheet Min ...
3
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2answers
119 views

How to measure small current waveforms using a uCurrent Gold and a mains grounded oscilloscope

I am attempting to use a uCurrent Gold as referenced by several SE posts such as measuring microampere current without noise with a mains-grounded oscilloscope, to observe the small current into an ...
0
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0answers
44 views

How to select current transformer

I want to build a system to measure and log current from 2 DC sources & 2 AC sources. Measurement range is 0.2 to 15 A. Accuracy needed is 0.1 A. Update rate is 100ms and AC source is 230V, 50Hz, ...
0
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1answer
29 views

Estimate minimum current draw for a device

I'm trying to sum up the minimum current draw for all devices fed by a buck converter in order to determine the necessary inductance value. The max current is typically easy to find on datasheets, but ...
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2answers
85 views

Non-intrusive measurement of current and voltage

Sorry if this question is too basic for this forum... I'm an interested amateur but far from a professional. I'd really appreciate information from someone more informed than myself. Hypothetical ...
0
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1answer
29 views

Control relay using split core current transformer

I have a YHDC SCT013-03 split core current transform which lists an output range from 0 V to 1 V for an input up to 30 A. My objective is to use this to open an close a contact switch. The way I was ...
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2answers
39 views

How to design aluminum alloy melting furnace with nichrome coil heater of 800 watt 26 swg coil?

I have 800 watt 26 SWG of length 9 meter nichrome wire and 220 volt AC supply. I want to heat nichrome coil up to 850C degree for aluminum alloy melting funace. How much current will I need? ...
2
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3answers
1k views

Measuring a small resistance, ~0.001 ohm

I have a low resistance resistor that I would like to use to measure the current through another circuit, but first I need to accurately determine its resistance. Its data sheet says it is 0.001 ohm +...
0
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1answer
41 views

What is technical difference (internal voltage) between Digital multimeter's current measuring ranges mA (milliampere) and A(ampere)?

Is there any difference in internal power supply (DMM's) while knob turned to mA and A. While measuring current in my microcontroller-module with keeping mA on DMM, I am getting brownout detected (...