Act of measuring voltage

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2answers
43 views

Effect of 2-terminal and 3-terminal Voltmeters and Arduino Voltage Sensing on Circuit

I am trying to build a board to sense circuit voltage relative to ground at different points on a breadboard. I would want the board to work regardless of configuration of the circuit. The only ...
0
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0answers
29 views

3 channel vs. 4 channel 120/240 power meter

So I live in the US, where we have center tapped power for residential use, with two hots and a single neutral wire. My question is what would be the potential effective difference in power ...
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3answers
89 views

Cross-talk in an RGB photodiode circuit

I'm trying to make an accurate RGB detector, where the R,G, and B components of a sample are measured via the voltages $$V_R, V_G, ~\text{and}~V_B,~\text{defined in the following circuit:}$$ Where ...
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1answer
73 views

how can we measure the voltage upto 2000V [closed]

i m having the voltage measurement device of 1000 V. but i have to measure voltage of 2000 V. what are the techniques that can be used to measure this voltage?
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1answer
52 views

A possible decimal digit dvm?

I would like to build a 3x10 decimal digit dvm for an edge lit numerical display. The nearest schematic that I can find is using a CA3162E / LM74LS147 which can be found at: ...
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1answer
59 views

Measuring 60 Hz AC from a piece of wire

I am trying to measure the presence 60 Hz AC signals using various shapes of wire antennas. I will be sending the voltage present on these antennas into a high impedance op amp stage. But before I do ...
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4answers
161 views

How would you solve this resistive network?

simulate this circuit – Schematic created using CircuitLab I'm not really sure how to solve this. I can't see any series or parallel connections. I need to find the Total resistance, V1 ...
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1answer
53 views

LED DC Voltage Level Indicator

I am wanting an at a glance indicator of what voltage level is being supplied by a DC generator (think pedal power). My general thought is a series of LEDs that light up in sequence as the input ...
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2answers
60 views

Input-output voltage vs needed voltage [closed]

I want to use a new modem-router to replace one fried by a power surge. Snake-bit by that, I checked out the voltage for the new unit's adapter. It's supposed to be 12V, 600ma. Using a ...
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2answers
97 views

DC non invasive power measurment

For one of my PhD project I have to measure power consumption from different electric wheelchairs during various tasks and recor these measurment for later studies. I have not much experience in ...
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0answers
111 views

How to measure microvolts of electricity in plants?

I'm trying to measure electricity in plants, to do something a bit like this: http://www.treehugger.com/culture/organic-electronic-sounds-from-plants-sonic-artist-mileece.html Basically, plants ...
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3answers
107 views

Measuring a voltage that is higher than your reference voltage

Question: How to measure an input power rail? Let's say I want to build a circuit that switches in a load that draws 1A from a 5V power rail (that is the supply for the device) and then measures that ...
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2answers
91 views

Need help with fundamental understanding of voltages in this circuit

Looking at the below schematic, with LED1 being a red LED (1.7V forward voltage) and LED2 being a green LED (3.2V forward voltage), I have a few questions that probably reflect lack of some ...
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2answers
61 views

Digital Voltmeter - TriColor LED Output

I'm very new to electronics and I wanted to start with something that would hopefully simple, but also useful. I'd like to make a circuit that can read a DC input voltage (between 9V and 20V) and ...
0
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2answers
72 views

Voltage Doubler stops 'Doubling'?

I constructed a simple voltage doubler on a bread-board. Here's the schematic. simulate this circuit – Schematic created using CircuitLab The output across the 100kΩ resistor was the ...
1
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1answer
356 views

What does pseudo-differential mean?

I often read the term pseudo-differential when looking for ADCs. I know common differential means that the ADC measures a difference between two of its pins (AN+, AN-). But what is the difference to ...
0
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1answer
51 views

What is the best practice to measure 3 phase grid voltage using a dsp chip for synchronization?

I want to measure the current grid voltage to synchronize a dc power supply with the grid using an inverter. Now I'm particularly interested in finding noise and harmonic information about the grid ...
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1answer
73 views

ZYNQ ZC702 measurements of current

I need to measure a current with the osciloscope on a ZYNQ ZC 702 board and I do not know what shunt resistor should I pick. I am not so good at electronics so if some one can help me I would be very ...
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6answers
103 views

Frequency DC voltage

Maybe it is a silly question, but a microcontroller it is powered up with a voltage of 3.3 DC voltage, and we all know that the frequency of the DC voltage is 0 Hz. Suppose that i want to generate a ...
4
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2answers
583 views

ATTINY85 measuring internal voltage

I'm using an ATTINY85 for a portable application that uses a Lithium-ion battery; therefor I need to monitor the battery voltage so I don't kill the battery. Is there a way to go about this without ...
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4answers
96 views

LED Voltage Drop Confusion

Please take a moment to checkout the simple circuit below: simulate this circuit – Schematic created using CircuitLab As you can see, this is a simple circuit consisting of three LEDs in ...
1
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2answers
91 views

Measuring voltage between two points…wirelessly?

I want to measure voltage between points A and B. Let's assume that there's some obstruction/difficulty in simply attaching cables between those points. Is it possible to measure the voltage ...
0
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2answers
121 views

Low voltage cutoff circuit

I'm powering an attiny45 from a lithium ion battery; using these batteries the voltage cannot get below 3volts or it will damage the cell. How should I go about cutting the voltage out? Software, or ...
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5answers
195 views

How measure the voltage over a large resistance?

I know initially this question might come across stupid and obvious but all is not as it seems. I want to measure the voltage drop over a 10M ohm resistor but my voltmeter's probes have an ...
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5answers
192 views

Why does ammeter or voltmeter measures RMS value

When there's an alternative voltage, why does the voltmeter measures rms value instead of the value at that specific time?
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1answer
87 views

Why is voltage 0 after the last component in a circuit given electron current flows from negative to positive?

Perhaps a different way to ask my question is why does voltage drop occur on the negative side of a component and not the positive given what is known about electron current? E.g. in the diagram below ...
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1answer
48 views

dual ramp voltmeter meaningfully displaying the microvolt digit

How can a common dual ramp voltmeter meaningfully display the microvolt digit when measuring a DC voltage ridden by a 50 Hz signal of several millivolts captured from the power distribution network.
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3answers
343 views

Wheatstone bridge why not use a voltmeter?

I have been reading up on the limitations of a Wheatstone bridge, one of which is that for high bridge resistances any imbalances are hard to detect because of the small current that flows through the ...
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2answers
343 views

Bench DC power supply output

I recently purchased a ATTEN APS3005D Regulated DC power supply from eBay and I'm having some odd and potentially alarming results that I'm trying to get my head around. Note: I'm testing this ...
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1answer
115 views

Provide power if power is not present already (circuit inside)

I am designing a simple controller for an automotive application. As you can in the schematic below, they system is consisted of a sensor, a gauge and a controller. This particular sensor shorts its ...
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1answer
72 views

How to read a wider range of voltages into the SA ADC on a PSoC4?

I want to read in a larger range of voltages into the SA ADC on the PSoC4, however as stated on the data sheet for the ADC component the different modes can only allow a range of 0 to 2 - 3 V and I ...
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1answer
678 views

How does a smart phone measure the battery power?

A smartphone (assume Android) usually displays the battery percentage from 0 to 100%. I am assuming this is the usable power capacity of the battery. I have several questions: 1) How exactly does it ...
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1answer
125 views

Measuring the charge of a battery while charging

Determining whether a 12V car battery needs charge is as easy as touching its leads to those of a multimeter. While charging from a vehicle's alternator, the multimeter method fails to determine the ...
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2answers
502 views

1000 watts, 220 volt, 52" length, Coiled Nichrome wire

I need to use Nichrome wire for heating purposes. My heating temperature could be among 200 Celsius, voltage should be 220V, wattage should be approximately 1000 Watts, and length should be 52 inches ...
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10answers
3k views

Why can a voltmeter still measure potential difference if it has a (theoretically) infinite resistance?

I am a physics teacher who did engineering and hated all things electrical! Hence when my students sometimes ask me how a voltmeter can measure the potential difference between two points if there is ...
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2answers
168 views

Why are null measuring methods considered to be very precise?

I heard a professor saying "it's a null method, so it is very precise". He was talking about the force balance pressure measuring method. I think in this cathegory of methods one can include the ...
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0answers
66 views

pin connection added

I am trying to communicate 24 hall sensor via arduino & 8:1 Mux . I am using CD74HCt4051E 8:1 multiplexer. Instead of hall sensor i have used potentiometer 24 nos and connected to MUX IC devide ...
0
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1answer
135 views

Resolution Digital Voltmeter

If I have a 3 and half digital voltmeter operating on the voltage range of 40V then what would be its resolution? While trying to solve this I found in one of the books that only active digits ( which ...
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2answers
115 views

Series RLC measurement result different with theory

I am measuring the current and voltage in simple RLC circuit: However,the result that I measured show big difference with the simulation result using Multisim. Why is there are a big difference ...
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1answer
348 views

What causes inaccuracy over time on a DMM?

Here is a piece of information from a datasheet of a DMM. The accuracy rates seemed interesting for me. I wonder what causes difference in the accuracy, especially the changes after 24 hrs? Is it only ...
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2answers
77 views

Combining power [closed]

On a computer power supply can I add 12 volts and 5 volts supply to get 17 volt supply? **Edited for clarification
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1answer
193 views

Single Phase Energy Meter using Atmega32

Version 1 : We are trying to measure the input voltage from the AC mains (which theoretically should be 230 V). The circuit to measure this is a simple resistor divider network as shown below. The ...
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0answers
151 views

Voltage/current Monitoring - MAX4172 + ADC vs. INA219

I'd like to add some monitoring of voltage and current on the +5V and +3.3V supply rails of a development board power supply. I'm currently debating between two approaches. The first approach is to ...
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0answers
80 views

Node voltage analysis of PMOS charge pump

Why is it that the voltages at nodes A and B are 3.7 V and 7.4 V respectively at a certain phase, i.e phase 1? And just the ...
1
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1answer
93 views

Measure battery voltage

For a LiPoly-accu driven device using the Olimexino-32u4 board (includes LiPoly charger) I want to measure the accu state (voltage?). How to measure the voltage without the need for a current ...
1
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4answers
134 views

MiniQuadcopter ESC connection

I have a picture here, sorry if it's ugly .. but let's think, they are my ESCs for my mini-quadcopter. My mini quadcopter is 3d printed, and as much as possible, I don't want to use bullet connectors ...
3
votes
3answers
4k views

Why does an oscilloscope show a different voltage from a signal generator?`

I have a Rigol DS1052E oscilloscope and a Rigol DG1022 function generator. I have just changed the oscilloscope fan for a silent one, as I found, as is commonly reported, that the original fan noise ...
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1answer
83 views

Modifying a chip on a bought voltage measurer

I have bought a battery checker for my RC LiPo battery packs. The battery checker can measure and alarm at low voltages between 2.7 and 3.8 volts, however with LiPo batteries, the interesting range is ...
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2answers
2k views

RMS vs DC(mean value) when calculating power of pulsed or rectified signals

When I have either a rectified signal (like the unfiltered rectified sine wave out of a diode bridge) or say a fast pulsed signal feeding a LED and resistor, in which both the DC component and the RMS ...
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1answer
126 views

Frequency modulated voltage measurement with VFC voltage to frequency converter and counter

I would like to measure the voltage across a nonlinear high voltage pulsed power circuit. The pulse is an underdamped RLC discharge but with some non linearity in the inductance. A quarter cycle is ...