Questions tagged [voltage-measurement]

Act of measuring voltage

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25 views

Slower Voltage Reading Times After Upgrading PC [closed]

I'm using an arduino to measure and send various voltage values serially via USB to my PC, where the data is then collected and stored via Python. Each voltage is sent as 1 byte (so 8 bits of accuracy)...
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2answers
50 views

How can chassis ground be used for voltage measurements in a device with components of differing voltages?

The manual for my HV probe tells me to connect my ground clip to the chassis. I can see how this would be good advice for say a 12V car, because the chassis is made the ground and every component uses ...
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0answers
75 views

Replacing an ammeter with voltmeter?

I have found this circuit of a millivoltmeter, and it seems like something which as a hobbyist I can do it, and the range of the measurement is very suiting one of my projects, but I would like to ...
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1answer
93 views

AC Nanovoltmeter for Arduino alike?

I have searched across web, but I am unable to find such a circuit. I am looking for a circuit of a AC nano-voltmeter in range 5-10 to 100 nV which output is suitable to be handled by some precise ...
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1answer
67 views

Voltage and Current Sensor for Alternating Current

I want to measure the voltage and current of a AC powered device using a micro controller like Arduino. I am unable to find it.(I am new to these). Is there a circuit or sensor which isolates from the ...
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29 views

Does the voltage supplied to a CPU differ per core? [migrated]

I'm currently trying to find a range of safe voltages for CPU overclocking. As a start, I looked at the automatic stock voltages: Without any Turbo-functions, the voltages in this case range from 0....
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3answers
47 views

how can I calculate the smallest measurable voltage for a given adc?

I have a project where I use 4 strain gauges in full bridge configuration with a hx711 module and an Arduino mini pro. How can I estimate the smallest voltage I can measure with a given adc from its ...
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0answers
83 views

Auto Scaling in a Multimeter

I’m trying to create a multimeter, I’ll be mainly using a 16 bit ADC (ADS1115), an ESP8266 on Node MCU, I’ll use the MCU to communicate with a phone app to switch between different multimeter modes, i....
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0answers
55 views

Measuring just half the sine wave of a current measuring transformer?

I'd like to measure current of electrical devices using one of those split-core transformers you clip around an AC wire, which has a built in shunt resistor and hence outputs a voltage. I'd like to to ...
3
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2answers
52 views

How to measure the output impedance of a Zener diode in avalanche?

I'm trying to measure (on the bench) the output impedance of this:- simulate this circuit – Schematic created using CircuitLab It's a Zener diode, and the applied voltage is sufficient to ...
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1answer
54 views

Compare tiny capacitance using comparator [duplicate]

I want to compare the capacitance of two tiny capacitors at around 10^-15 F each. One will change compared to the other by at maximum factor 3. I need to measure the relative difference between them ...
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4answers
2k views

Measuring voltage across 1 ohm resistor

This might be a very stupid question, but I can't seem to figure this out and I'm going nuts thinking about it. Assuming you are trying to adjust the fixed bias of a tetrode push pull pair in a tube ...
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1answer
40 views

Advice on a voltage measuring circuit

I've been working on a voltage divider circuit that will hopefully allow me to measure voltages between 0-60 kV DC (80 W) as 0-889 volts DC. The voltage divider section that is used to measure the ...
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0answers
36 views

How to find current and voltage of a certain appliance connected to an outlet?

Objective: I'm new to electricity and trying to convert my mirror integrated with LED work with a power bank. I need to find how much voltage and current is needed to make it work. How can I measure ...
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2answers
46 views

Explanation for Method of Monitoring Current from a Power Supply

I recently came across an interesting way to monitor current, but was not certain exactly how it works. Likewise, I was hoping that someone might be able to explain how the device measures current. ...
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1answer
41 views

Simple voltage presence monitoring with negative power supply

I am switching a 230-240 V load with a TRIAC and relay while also monitoring the presence of voltage on both ends of the load (i.e. not measuring the amplitude -- just that the switch successfully ...
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2answers
86 views

LT1510 as a CC and CV Battery charger

LT1510 is a battery charger IC that can be configured to charge any kind of battery pack, I am interrested about the circuit given in the application note referenced AN68F page 24/36. The IC is used a ...
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1answer
50 views

Measuring Output Ripple Voltage

Please check the below waveform of my 5V output ripple of the buck converter. I am measuring the output ripple across the output capacitor of the converter. Why are these spikes coming while ...
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2answers
68 views

Voltage divider resistor PN balancing

Refer the representational schematics for voltage sensing by ADC (SAR). I read somewhere to balance the P and N lines add R3 = R1||R2. How come R1 and R2 parallel combination could be considered as ...
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1answer
162 views

acs71020 Connecting and reading voltage properly

I am using an ACS71020 3.3V I2C version hooked up to ESP32. I have connected the IC as proposed in the datasheet. Rsense used is 1.8k ohm as proposed in the evaluation board user manual for 230-240 ...
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2answers
40 views

Measuring output voltage (Single ended probe vs differential ended probe)

I have a SMPS buck 3.3V output. I am trying to measure the output voltage at the output capcacitor using Oscilloscope. I am using a single ended probe with spring ground tip to measure the output ...
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1answer
19 views

Effect of the horizontal magnifier control on the sweep speed, sweep time and number of cycles observed?

What is the effect of the horizontal magnifier control on the sweep speed, sweep time and number of cycles observed? Sweep speed increases by ten times for a 10X magnifier, sweep time reduces by the ...
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1answer
44 views

Measuring Voltage drop across MOSFET 2N7000

My setup is 2.1V on the gate. A 330 Ohm load between Vdd and drain. And Source to ground. I stepped Vdd from 0V to 9V in small increments and measured the current through Vdd to ground. Got currents ...
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0answers
24 views

AC Measurements: Level Shifter vs Negative Voltage Supply

I’m trying to design a circuit capable of measuring AC signals with a high level of accuracy. The two most popular options I’ve seen so far are: a) Supplying the ADC with a negative ground supply (2....
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2answers
39 views

Use single-pole voltage detector to check for currentflow on a lamp

I am using a single-pole voltage detector to detect if there is a current-flow / potential on the clamps of my ceiling lamp (See device in first picture below). When the ceiling-lamp is ON and ...
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1answer
81 views

INA219 bus voltage depends on supply voltage

I tried to measure voltage with INA219A connected to Arduino. As datasheet says INA219 works from 3V to 5.5V supply voltage but I get different values for bus voltage when I change supply voltage. ...
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31 views

Temperature coefficient of a voltage source

Is the temperature coefficient of a voltage source related to the internal resistance of the voltage source? Why does the voltage increase/decrease when the temperature is increased or decreased? In ...
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2answers
74 views

touch sensor for metal door handle

I was thinking if a current is applied to a metal door handled and somebody touched it that should complete the circuit to ground and be detectable but I'm not sure if this would work as the 'somebody'...
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1answer
40 views

How to find out the maximum current across a voltage source(using a DMM)?

I have an old Nokia phone charger lying around which I want to adapt for powering my breadboard/PCBs. I was trying to find out how much current the charger was able to supply, so I connected a DMM ...
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0answers
26 views

Battery monitoring using voltage divider circuit using 4 resistor

I want to measure the battery voltage using voltage divider on different ADC channel, as shown in image i have to used 4 resistor and generate 3V, 2V, and 1V from 4V battery. i want to measure all ...
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0answers
10 views

Insertion loss measurements, frequency sweep vs measuring points with a constant driving frequency

I have been modelling a surface acoustic wave delay line, and am trying to clarify what I am seeing in the different models and whether this is applicable to what would occur experimentally. In the ...
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1answer
67 views

Contact potential between metals

Metals Al and Au are connected in series. An ideal voltmeter, with both of its leads made of Cu, is connected across them. Then how come the voltmeter gives zero reading but why can't we measure ...
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5answers
2k views

Does an oscilloscope subtract voltages as phasors?

I want to measure two voltages on an oscilloscope. They are not in phase. I want to know the magnitude of the voltage difference. The oscilloscope has an in-build math function to subtract the ...
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0answers
30 views

How do I measure the fluctuation of a pulsed voltage of ~1700V?

The problem: See the little sketch. Starting from a high-precision DC power supply, I pass the voltage to low-pass filter and a pulser. This pulser pulses the nominal voltage of around ~1700V down to ...
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1answer
76 views

LM339 Lipo Battery Voltage Tester Circuit - How does it work?

After reviewing the eevblog video on OpAmps and various other videos on the LM339, as well as copying a circuit which works, I am still genuinely confused on the math / logic behind this, which makes ...
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1answer
50 views

Help finding voltage between two points

So, how should I proceed to find U_ab (or V_ab)? I have found I = -0.5mA, U_1=-2.5V, U_2 = -0.5V, U_3 = 2.0V. How would I even find U_a and U_b separately so I can apply U_ab = U_a - U_b? Also, ...
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1answer
147 views

Useless pins in HDMI cable?

In order to connect two small electrical circuits, I needed 17 pins. Because of its availability and compact form, I chose the HDMI connector. The two circuits are connected using an HDMI cable that ...
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0answers
25 views

How can I convert FMCDAQ2 Analog Devices Data Acquisition board from AC-Couple to DC-Couple input?

This is a Data Acquisition FPGA board from Analog Devices: https://wiki.analog.com/resources/eval/user-guides/ad-fmcdaq2-ebz/hardware#picture_and_main_components We have to use this card in a project ...
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0answers
28 views

Fluke 322 clamp meter

My meter will read 11 to 14 ohms when leads are touched together. When trying to read AC or DC voltage with leads or clamp I get no reading at all? I did remove batteries and took the unit apart ...
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1answer
105 views

Measuring battery voltage and impedance

I have been trying to figure out how to properly measure battery voltage for a few days. The more I read, the less I understand. I know there are many questions like this out in the internet and I ...
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0answers
79 views

What do these capacitor markings mean?

Aluminum Organic Polymer Capacitor So to be really honest, I did blow an capacitor a while back by applying the wrong voltage to it, and had ever since then trying to decode this info to track down an ...
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2answers
117 views

Why doesn’t voltage drop to 0 when a capacitor becomes fully charged?

This is my understanding so far of what capacitors are and how they work, if it helps to answer my question at a level I can understand: A capacitor is composed of two equally sized conductive plates ...
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4answers
104 views

Does resistance decrease over a resistor?

If ohms law pertains to voltage, current, resistance across a resistor, in order for voltage to drop, and current to remain the same, does resistance drop as well across the resistor? To explain what ...
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0answers
46 views

High quasi-isolated voltage measurement

I have to measure a DC voltage and an AC voltage around 100V. I found the circuit with an AD629 and one OP177. I simulated everything in Spice and it works fine, at least in the simulation. In ...
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0answers
33 views

Measuring battery life for Arduino device [duplicate]

I'm building a IoT thing based on Arduino. The thing will be powered by a 12V battery. The reason why I want to use a 12V battery is because I will also have motors on the thing. I would like my ...
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0answers
247 views

ZMPT107 + Transimpedance Amplifier + Opamp voltage divider: is this circuit work?

First Sorry my basic knowledge about electric and also English. And sorry title of question is not clear enough. Please correct me if I wrong, Thanks so much I'm trying design my own household energy ...
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1answer
100 views

Analog input like in a PLC: Thermistor or 0-10V

Depending on the configuration, PLCs can often measure 0-10V, resistance or 0-20mA on the same set of screws. How to use the same screw terminal to measure resistance of an NTC element, voltages in ...
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1answer
42 views

Multiplex Sigma Delta ADC outputs (AD7401A)

i'm measuring 30 different voltages without common ground. Each voltage is measured by an AD7401A Sigma-Delta modulator/ADC. The signals go into an FPGA (Xilinx Spartan 6). But the I/O-Pins are ...
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1answer
103 views

Transformer less Power supply's waveform is Noisy

Hi I want to measure the mains voltage using transformerless power supply. the output of the supply is fed to an optocoupler and later read by a microcontroller. The problem i am having is that the ...
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3answers
136 views

Measure 10kV with 600V rated multimeter [duplicate]

My multimeter is rated for 600V but I need to measure a 10kV AC source. I was thinking of building a voltage divider but I wouldn't know how many resistors it would take to safely measure this high of ...