Questions tagged [shunt]
The shunt tag has no usage guidance.
179
questions
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24 views
Comparator H Bridge current sense negative voltage input
I'm using lm339 basic comparator to sense current from an H Bridge. Current limiting was done somewhat successfully with acs712 after removing the capacitor from filter pin for limiting the bandwith. ...
0
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1answer
48 views
H Bridge vs Half Bridge current sense
Are there any disadvantages in measuring H Bridge current only via 1 shunt resistor?
Since it will be made by hand on a perf board the only disadvantage will be the possible longer wires that connect ...
2
votes
1answer
43 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 ...
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1answer
44 views
ADC Measure from source with higher voltage and different ground
I would like to measure the voltage of a battery that varies from 4,5V to 3V.
To do so I'm planning to connect this source to a STM32F4 DISCO board and one of its ADCs, which will be set to a VREF+ of ...
0
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1answer
52 views
Op Amp High Side Current Sensing
I'm trying to build a high-side current sensing circuit with a differential op-amp which can be seen below:
The LT1006 is actually an LM358 IRL(I know it's a peanut op-amp, but it's what I have ...
6
votes
3answers
720 views
Why cap across shunt resistor, input bypass caps and small resistors on current sensing inputs?
I want to build a sensitive current sensing circuit using shunt, and since I also repair MacBooks occasionally, I have some contact with the schematics of real working expensive devices (although ...
0
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1answer
39 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 ...
1
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0answers
35 views
Rectified DC current measurement using shunt or Current Transformer
I am working on a project to design a controller for battery charging solution.
A 3 Phase delta power (440 Vrms ph to ph) is given to a 3-phase Variac Transformer ( Variac is operated ...
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0answers
32 views
What is the value of this shunt resistor from a drone power distribution board?
What is the value of the shunt resistor shown below? It is from the drone power distribution board, rated for up to 120 A. I am guessing, that the value is 0.25 mOhm. However, even with this value, at ...
1
vote
3answers
123 views
Non inverted OpAmp & Shunt circuit not working
I am trying to measure the output from a Hall effect sensor (LEM-LF 310-S) for a welding application.
The maximum output of the sensor is 0-0.25A when sensing 0-500A. This range I need to convert to ...
0
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1answer
81 views
High Voltage DC - Shunt Resistor, Voltage Regulator Question
I'm a newbie here but was trying to wire a setup and was running into some issues attempting to calculate my required resistance, and resistor tolerance to current.
I have a power supply that brings ...
1
vote
1answer
131 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 ...
5
votes
3answers
2k views
How do I amplify the difference between two voltages?
Starting at the beginning: I have a shunt that carries DC current, and the voltage drop is very slight. I want to amplify it in order to see it better on oscilloscope, and to have it scaled correctly ...
0
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0answers
38 views
DC shunt motor electrical
A 5KW, 220V DC Shunt Motor draws 2A at rated voltage when running light. If the
armature and field resistances are 1Ω and 165Ω respectively, determine its efficiency
when running as a motor drawing an ...
0
votes
2answers
26 views
Measuring current output of a diode driver
I have a laser diode driver chip that can produce DC currents up to 200mA. The current is adjusted by a potentiometer on the driver chip. The driver chip has four pins:
inputs: GND, SUPPLY
outputs: ...
1
vote
2answers
44 views
Calculating uncertainty in a current divisor
I had the following exercise to do for college:
I designed an analog ammeter exactly like this:
simulate this circuit – Schematic created using CircuitLab
The idea is to design an ammeter ...
2
votes
2answers
142 views
What is the purpose of clamping the gate and source of a mosfet
Is clamping the gate and source of a MOSFET really important? I have seen this in some articles and some datasheets of MOSFETs where they have built in clamping.
As far as i know they are used for ...
0
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3answers
70 views
Why don't we need to consider \$R_4\$ and \$R_5\$ when why calculate \$I_1\$?
My book said that \$I_1=I_T \times \frac{R_1}{R_1+R_2}\$,and \$I_2=I_T \times \frac{R_4}{R_4+R_5}\$
simulate this circuit – Schematic created using CircuitLab
I have two questions about these ...
0
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2answers
91 views
Why does the voltage across a shunt spike then settle?
I'm using a 50 Ohm shunt to measure a current of about 50mA driven by a voltage of 110v 60Hz AC as a zero-crossing square-wave (with a step at the zero-crossing).
Using my oscilloscope I can see ...
0
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1answer
93 views
How can I accurately and precisely measure current in a 110V AC circuit, with a 1kohm-50kohm load, using an oscilloscope?
I need to measure the electrical resistance of a volume of ground.
To do this I need to cause a current to flow between two metal electrodes pushed into the soil (let's call them the "current" ...
1
vote
2answers
83 views
LDO quality with current measurement shunt
I'm designing a power supply block and need to measure the current flowing trough a LDO. It is clear that the current in front of the LDO and after the LDO are the same (apart from some tiny bit used ...
1
vote
1answer
155 views
How to connect 50 A 12AWG cable to a shunt resistor in PCB?
I'm designing a PCB in which the current of a BLDC motor is measured through a PSG4NTEBL500F shunt resistor. The DC supply of the motor is connected to the PCB through a 12AWG cable and the circuit ...
0
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1answer
47 views
How to select shunt resistor value of the below circuit? We can use Ohm's law but I am still a bit confused
I am very new to hardware development. I am learning all the basics to design a battery management system for electric vehicles in the future.
I would like to know how to select a shunt resistor for ...
2
votes
3answers
239 views
large voltage spike over shunt resistor even at no load
I'm trying to build a stepper-motor driver. Each windig is driven as shown:
at the moment, im feeding this with PWNM signals of constant duty cycle, just to see how everything response. (PWMs are ...
0
votes
2answers
149 views
Wrong ground reference producing wrong output on ADS1115
I am currently working on a project, which involves measuring current in a DC circuit and storing that generated data on an arduino microcontroller.
I decided to go with the ADS1115 and a shunt, which ...
0
votes
2answers
72 views
Understanding purpose of a resistor in reference schematic TIDU034
Gents,
I'm analyzing this schematic, but do not understand couple of things. I would be grateful if someone could explain in detail these questions:
1) R6 - shunt? What's the purpose of it? Under ...
0
votes
2answers
87 views
Poor Buck Converter Current Limiting?
I am planning on using the XL7026 buck converter IC in an upcoming project because of its dirt cheap cost, small package and wide input voltage range.
However, there is one concerning aspect of the ...
0
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0answers
31 views
Shunt Resistor Color Code wrong or different [duplicate]
For a project, I was tasked with identifying some components. To identify all the resistors, I use the digikey calculator which so far gave me correct values. However, with that specific resistor ...
0
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0answers
148 views
Measuring micro-amps with INA series
I'm designing BLE devices and other low power embedded systems that can consume very low energy in the range of a few micro-amps.
I can't afford any expensive precision multimeters. Hence, I'm trying ...
0
votes
1answer
106 views
Measuring output of op-amp current shunt circuit using ADC
This is my first post here, so I hope I have done it correctly.
I am rather new to analog circuits, so undoubtedly I've overlooked something.
Here is what I want to do: Using a 24-bit LTC2400 ADC, ...
0
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1answer
61 views
Question regarding shunt regualtor using zener diode
simulate this circuit – Schematic created using CircuitLab
I am not able to get proper 3.3volt output at the output capacitor. Since 3.3 volt zener diode have been used, there is a drop in the ...
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1answer
43 views
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1answer
866 views
Why is my Voltmeter/Ammeter not reading amps correctly?
I am having problems correctly setting up my volt/ammeters. I am attempting to use them to monitor a boost converter I recently purchased. I would like to have one set up on the input of the boost ...
0
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2answers
194 views
Can I use a regular 2512 SMD Resistor (0.001 ohm) for HLW8012 IC shunt Resistor
Can I use a regular 2512 SMD Resistor for the shunt resistor as current sensing resistor for the HLW8012 power meter IC.
As per the data schematic, the manufacturer recommend to use a shunt resistor ...
0
votes
1answer
37 views
What is the predictable difference of the voltage drop between the V+ and V- lines on a shunt resistor?
I am making an electronic speed controller, and the half-bridge driver I am using has a built-in overcurrent protection feature. In order to utilize this feature, I have to supply the pin (a ...
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3answers
271 views
Current measurement with shunt
I need to measure pretty high currents (maximum 100A) flowing from one battery to another. I came up with a solution involving the measurement of the voltage drop across a shunt resistor. The supply I'...
0
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0answers
63 views
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 ...
2
votes
2answers
316 views
Full wave rectification by opamp
I am trying to read a current waveform from a shunt resistor series with the power line.
Using a full bridge rectifier, I got the following waveform:
The waveform was sampled every 2 millisecond ...
0
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3answers
353 views
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 ...
0
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0answers
72 views
Current Transformers
I have a question about current transformers being used to measure AC currents.
Say for example, we have a 50/5 amp current ratio, meaning that when there's 50 amps on the primary, there will be 5 ...
1
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0answers
176 views
High pass shunt filter
I have a DC motor, which is used as an electromagnetic brake. However I want to leave certain frequencies uninhibited, so I thought this should be possible by adding a shunt filter on the DC motor ...
0
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0answers
70 views
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 ...
0
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0answers
128 views
Shunt Shunt Feedback SImulations
I am trying to simulate the solution to an old text book example on a simple Shunt-Shunt feedback amplifier.
simulate this circuit – Schematic created using CircuitLab
The book only shows BF = ...
1
vote
1answer
287 views
DC Shunt Motor Load Loss
I have three DC shunt wound motors in series. Each motor has a coupling to a transmission. I am trying to work out (mathematically, as opposed to intuitively), what happens if the coupling was to drop ...
0
votes
2answers
89 views
What could be the output current rating of the following shunt regulator?
I am trying to solve the 2013 paper set by ISRO for electrical engineers. I wanted to verify if my answer to Question no 18 is correct.
So \$I_L\$ is being drawn out of the circuit shown. Since the ...
0
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2answers
72 views
Does short circuit always (in every electronic circuit) shunt the resistor that has both sides connected to the short circuit branch? [closed]
I wanted to know if short link always (in every electronic circuit) shunt the resistor that has both sides connected to the short link branch
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2answers
475 views
Shunt resistor with ADS1115 [closed]
I am trying to develop an off grid solar monitoring system. In order to measure solar input current I am using a 50 A/75 mV shunt with an Adafruit ADS1115 (VDD=5 V).
However, when I ...
1
vote
1answer
298 views
Constant current source with shunt fet
I'm want to create a project with a LED strobe with IR LEDs.
As LEDs the Osram SFH 4249-UV will be used in strings of 15 LEDs and 32 strings parallel.
This results in a Vf of 34.5 - 45 V and a If of ...
2
votes
1answer
508 views
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 ...
0
votes
1answer
44 views
Measure unknown load resistance on battery terminal
I need a method to measure the load resistance attached to the terminals on a battery. I want to determine this load before I turn mosfet on to let battery pack discharge. Most important I want to ...
