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Questions tagged [electricity]

For EE.SE purposes, the creation (battery/generator/solar cells), storage, control and transmission of electrons. This can be broken down into sub-topics such as voltage, current, reactance and ohms. These can be broken down into more sub-topics such as electromagnets, coronas, heat, ESR, EMF. This excerpt just touches on all the endless fields electrons are involved in, including physics.

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How many hours should I charge this battery? [on hold]

I have a charger and two batteries, the charger has output 250mA with voltage 2.4V, the battery is 1900mAh with voltage 1.2V, how many hours should I charge this battery? Should I charge 1900*1.2/250/...
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1answer
54 views

Why does a dielectric liquid need to immerse the parallel plates in a conductivity cell?

For a parallel plate conductivity cell with a liquid dielectric in between, after filling the liquid to the point where it is just enough to fill the space between the two electrodes, does the liquid ...
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0answers
35 views

Transfer Function / Cutoff Frequency

I am trying to get the formula for the cutoff Frequency out of this transfer function: . I think this is the transfer function: . And I get this formula for the cutoff frequeny: Calculation ...
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4answers
89 views

Why are replacement plugs in the US only rated at 125V even though many of our devices can also be run on 220V?

When I search for replacement plugs at Home Depot or Amazon (US), all I see are plugs rated at 125V. Even plugs marketed as "heavy duty" are still only 125V. Here is one such example. The only ones I'...
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0answers
29 views

Connections Kaiser 50 kVA [closed]

I bought a electrical generator for a photovoltaic system, the thing is that this system works without grid and we need this generator as an emergency. The model is a Kaiser of 50 kVA as I've said ...
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2answers
94 views

Cannot jump-start car directly when I disconnect the dead battery

So I have a car B with a dead battery and a good functioning car A. I remove the dead battery from B and connect the terminal directly to car A's battery terminals. I cannot start car B. I tried to ...
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2answers
66 views

When jumpstarting a car, why do I need to wait a bit for the bad battery to charge a bit?

So I have a car A with dead battery but good everything else and a car B with good battery. What I did was disconnect car A's dead battery, connect car A's terminals directly to car B's battery. When ...
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2answers
75 views

How can I make a failing relay more reliable?

I have a non-accessible relay that I believe is failing and working intermittently. It doesn't need to actuate more than once or twice a week. It is activated with 12v and switches 12v 15amps. If I ...
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1answer
26 views

Choosing the appropriate power plug for a given fan motor

In a fan motor I have, the written specifications are as follow : "dual power: 110/230v 50/60Hz 22/20w". I would like to power the motor directly, without electronic parts between any 220V wall ...
1
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1answer
119 views

Signal filtering, what's wrong with the circuit?

I have this circuit where I receive a protocol signal: The +L_IN signal is this: This signal has a 28V DC voltage. The signal at ...
2
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1answer
109 views

Are there any electrical components which may keep electricity inside them after the device is turned off?

Is there any electrical component where electricity may remain after a device is turned off?
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0answers
22 views

Concentric cylinder cell constant

For a concentric cylinder cell (with liquid dielectric), mathematically the equation for the cell constant will always yield a lower value than for the parallel plate case for the same volume of fluid....
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1answer
53 views

Assembling and Dis-assembling a Charged Capacitor

If I have an electrolytic capacitor, which is a cylindrical body in which the two plates are rolled-up with a dielectric paper in between them, of very high value (say 1F) and I charge it using a DC ...
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0answers
18 views

Nidaq Timing Issue? Sensor Readings Consistently Early

Testing our sensor via Nidaq. When target gas interacts with sensor electrode, electrical impulse given and read to nidaq, basic setup. Our readings are consistently showing detection early - ~8 or ...
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1answer
23 views

Fringe field effect: calibrating vs guard electrode

Which method is more effective at limiting errors associated with the fringe field effect when performing a liquid conductivity measurement, using a guard electrode or using a reference liquid to ...
0
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1answer
20 views

Fringe field effect in cylinder conductivity cell

In a coaxial cylinder conductivity cell with the inner electrode electrified and a dielectric liquid between them, how is the fringe field effect dealt with? Is the effect as severe as in a parallel ...
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0answers
23 views

Cell constant and conductivity cell design

When comparing a concentric cylinder and parallel plate design for a liquid conductivity cell, which design is more favorable to get a smaller cell constant in a practical setting and why? (See below ...
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0answers
43 views

Adequate Power Supply for 300 Daisy-Chained LEDs [closed]

I have 300 LEDs (ws2812b) wired in a series. They were sold as 150 LED/5 meters and rated to power at 9W/m, so 45W/5m strip. I would need 90 Watts to power my entire 300 LED strip. I have a 3-rail ...
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1answer
61 views

Styrofoam cooler/chest ok for electronics project?

I'm building a DIY power supply using 6 server power supplies. I've been looking for a case/enclosure to hold them and the necessary wiring and came across a styrofoam cooler that's the perfect size ...
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2answers
67 views

Wireless Electricity Transmission model not working. Why?

I made wireless electricity transmission model using the principle of magnetic inductive coupling to transfer electricity between two separate coils. The model is very simple, known to everyone and ...
1
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0answers
40 views

Choosing the right power-switch with LED for a simple electrical design

I want to add an ON/OFF switch with an integrated indicator LED to a very simple electronic design, between a 9v battery and the connected module that it powers. What should I be looking at to select ...
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1answer
57 views

How to calculate the 3dB point?

I understand this until the final two lines. How does he get from 27.8766 to 1149.8hz and 7224.7rad/s?
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1answer
40 views

what is the difference between active and reactive power?

What is active and reactive power ? does the active power means power flows from source to load and reactive power as its vice-versa?
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2answers
53 views

Nodal analysis of a basic DC circuit

I am trying to find the v1, v2, v3 and i5 using nodal analysis. I gave the name to the current over the respective resistors i3 and i4 and put it as i0 - i3 - i4 = 0 also write the equations as i3 = (...
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1answer
43 views

200AH lead acid battery

I have a 12V 200AH lead acid battery and I want my load be a power resistor and a bulb. Does the batter draw current based on the load resistance? so meaning the current that will be drawn in this ...
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0answers
50 views

Difference between DC and AC liquid resistivity measurement

After reading a bit online it seems for more conductive liquids AC current is used to measure the resistivity which is apparently to do with polarisation effects, while this effect is negligible in ...
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1answer
62 views

Current flow in circuits and nature

This video shows that current only travels in circuits or "circles". This is in a way intuitive because a battery needs the electrons to return otherwise the reactions inside won't continue (I guess). ...
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6answers
1k views

Could transporting electricity using plastic water pipes be feasible?

Normally a household is connected with 3 different connections: Waterpipes Electric cables Internet fiber Water conducts electricity (and can also transport light), why aren't we transporting ...
3
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1answer
64 views

How does peer-to-peer energy trading work?

I am relatively new to the topic, with not the greatest electrical engineering background, so these questions may sound simple, but I still cannot figure out how certain platforms such as piclo, ...
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3answers
159 views

Static Electricity Accumulation

I don't know much about electricity. I live in an old building experiencing bizarre electric phenomenon. The building might have bad wiring, I live near elevators and power distribution for the entire ...
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2answers
60 views

Averaging 1 min kW values

I have some time series data, with values of active power every minute in kW. Now, I am not an electrical engineer, and I would like to average them out per hour. My questions I guess are: do I ...
2
votes
2answers
91 views

Protect Inverter from Transformer's Inrush Current

Consider a "small" autonomous grid, which is based mainly on RES and has a few diesel generators, like in the following figure Everything runs smoothly, feeding the small load. Suddenly, the big ...
2
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1answer
84 views

Measuring resistivity of dielectric liquid

Is it possible to reliably determine the resistivity of a highly resistive liquid above the breakdown voltage (i.e. after ionising the substance)?
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2answers
37 views

Can I connect a 15A surge protector to a 13A extension cord?

As someone who’s studied engineering, I should be able to answer this question. However, a quick search online has me confused. Provided what I’m plugging in (a laptop drawing relatively little power)...
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0answers
45 views

Equivalent Circuit of Howland current Pump

Why is at norton circuit for Howland current pump the current source is taken as vi/R1 instead of vi/R0? Because the formula for Norton current is IL=In*(Rn/(Rl+Rn))
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1answer
74 views

Calculate the turn-off delay of an LED in parallel with a capacitor

I am trying to create a Custom turn off delay for an LED. For this I take an Capacitor in parallel to an LED My Idea so far was: I have the General Equation for an Capacitor. And the General ...
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3answers
37 views

Predictions based on resistance measurements not matching reality?

I'm using my multimeter to measure the resistance of my tongue, and leaving it on there for a full minute it seems to average out at around 1.5 Million Ohms. However, when I put a 9 volt battery on ...
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5answers
256 views

Can a 9 volt battery through your bloodstream kill you? [closed]

I usually try to do some research before asking questions on this site, but everything I've found has been contradictory. If I were to direct the positive and negative ends of a 9 volt battery ...
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2answers
91 views

How to use a multimeter to test the resistance of my tongue?

I just purchased this cheap-o multimeter: https://www.amazon.com/AstroAI-Digital-Multimeter-Voltage-Tester/dp/B01ISAMUA6/ref=sr_1_1?keywords=astroai+am33d&qid=1551837071&s=gateway&sr=8-1 ...
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1answer
149 views

Why can my body conduct electricity from a 9 volt battery?

I've created a scenario represented identically in the attached image . My question is this: When I connect Jumper 1 to my left hand and Jumper 2 to my right, the LED turns on very faintly but I feel ...
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3answers
49 views

I have the following phasor −j3e^(−jβx). How can I find just the real part

−j3e^(−jβx) for this phasor I am trying to figure out what to do with the -j3 thats is being multiplied by the expodentional. I am not sure how I can find the real part with this being there.
2
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1answer
102 views

Strongest electrical wire at AWG 24

Is there any ultra strong electrical wire at about AWG24 (0.22mm)? I want something that would be strong as a steel wire rope but also with low resistance that can used as electrical wire.
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1answer
65 views

Clarity on dB SPL calculation

Based on this post, let me assume that I have a input source of 94 dB SPL / 1 Pa that a microphone is picking sounds from. The microphone has a sensitivity of -46dBV/Pa , this gives 0.005012 V RMS/ ...
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1answer
57 views

NPN Transistor 2N2222 fixed bias MULTISIM

I have been working on my school projects and I wanted to ask you if there is any way of editing BETA for transistor. When I click on transistor, Edit Model is not working. Anyone help me, please.. I ...
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1answer
37 views

Corona and conductor

We are decreasing corona by increasing conductor size and making it hollow but according to definition corona depends on level of voltage so eventhough you make it hollow and increase conductor size ...
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1answer
37 views

Induction loop resistance calculation

I have been trying to build a simple induction loop amplifier. I am using TDA2040 as an output stage and it delivers 10 W (I limited it for that). I am using about 14 meters (1 mm thickness) loop. My ...
0
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1answer
112 views

speaker problem with high volume

I am trying to build an audio system . I have a speaker which is rated 10 W and 8 Ohms . I am using a circuit from datasheet of TDA2040 with a pre-amplifier circuit with the microphone . when I ...
0
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1answer
75 views

Can a 125mw dual gang pot handle 10w audio output?

I want to build balance control for two audio amplifier circuits, and I want to use dual gang pot. I want to know if I connected it directly to the outputs of the two audio amplifiers circuit then to ...
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1answer
52 views

What does this bidirectional TVS diode do

This is a schematic for a crude taser design ive been studying. From what i can tell when the switch is on the relay turns on and off continuously, which charges up the LC circuit in which the ...
0
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1answer
84 views

What defines Volts, Amps, Watts and mAh?

My current understanding is as follows: Volts: Speed of electron flowing. Amps : Number of electrons flowing. Watts: Amps x Volts measured for "some" time. mAh: Very confused to come up with ...