# Questions tagged [electric]

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46 questions
66 views

### Run electric motor CW & CCW with DP-DT switch

I have a Harbor Freight drill press 1-1/2 hp, running on 120 volt, capacitor start. Is it possible to run CW & CCW rotation, using a DP-DT switch? Motor has four wires coming out of it, all ...
33 views

### In a conductive wire, a set of electrons with equal charge 6 C pass through a section of wire in 2 seconds [on hold]

In a conductive wire, a set of electrons with equal charge 6 C pass through a section of wire in 2 seconds. What is the value of the electric current in this wire?
64 views

### Voltage changing [on hold]

I'm finding a problem with changing voltage ! I will explain by example: lets assume I have a voltage source which it's 20v , connected to specific circuit, that circuit have resistor which the drop ...
86 views

### How to make my own sequence of numbers and letters in a seven segment display circuit? [on hold]

In this circuit, I have connected a single switch to a priority encoder, which is then connected to some inverters, further connected to a binary decoder, then to some current limiting resistor which ...
4k views

### Why does magnet wire need to be insulated?

What is it about having multiple coils that enables the magnetic field? Why can't I just have one big wire or threaded wire on a motor? Sorry, it's kind of a baby question but I couldn't find the ...
58 views

### Circuit Failure How to fix it? [closed]

I'm sorry I am very specific here, I have a problem with the charger of my motorbike dashcam and I hope you can help me fixing it (see picture and video test with multimeter). I really have no idea ...
59 views

### Two Doors Two Locks project

I'm now reforming my apartment and I want to make the bathroom with two doors. for that I want to make a simple electrical locking system so people wouls not need to lock the two mechanic locks. ...
95 views

### Understanding oscilloscope pattern

This is likely an obvious question for anyone with professional experience but I'm just a humble software engineer trying to fathom the mysteries of my oscilloscope... I created a simple square wave ...
638 views

### Mixing Lead acid and Lithium ion in series, after charging them separately

Can I connect a Lithium ion battery battery pack with a Lead acid battery bank; in series. I will charge both separately cells strings separately (not to mix the chemistries) before putting them in ...
42 views

### Power consumption for an in-wheel motor

I'm trying to estimate the power consumption of an in-wheel electric motor. I used the formula $$P = T\cdot\omega + K_m\cdot T^2$$ where T is the torque, ω is the motor angular velocity and \\$...
182 views

### Designing 60hz antenna to detect electric field

I am working on designing an antenna to detect 60Hz electric field. I came across the microstrip antenna being used to detect the field. Before designing the antenna I wanted to maek sure this is the ...
64 views

### use battery to generate weak electric field?

i am a biology student interested in how marine animals react to weak electric fields. My professor and I want to do a trial experiment and were hoping to rig something up ourselves for cheap. Is ...
723 views

### Soft start for fridge compresser

I live in an off grid property running on 6 12v batteries. We have a 2000w inverter and are trying to get a fridge to run on our system. We have enough power to run it however the issue I am having is ...
473 views

### What Reference-Potential does an Operational Amplifier use as “Ground”-Potential?

Wikipedia states on operational amplifiers, that, simply speaking, they provide an output voltage at their output which is the difference of the two input voltages, multiplied by some (very very large)...
97 views

### Is a normally high switch the same as a normally closed switch?

I'm very much an amateur when it comes to electronics so apologies for the stupid question. I have a switch that is normally high (5V) and then when i hit the mechanical button it drops to 1V. I need ...
103 views

### How is power out one side of 220 only - Problem is with incoming 3-phase. But how?

[EDIT] Can someone who understands what I wrote explain this? [EDIT 2] Sorry I didn't say I'm in the USA, the power is 110/220vac 60Hz. The input to the main power transformer is 3-phase, underground,...
27 views

### How to know if a motorcycle battery and power generator is enough to keep an device turned on without discharging the battery?

I have an arduino project in mind but I have some questions before I can start to make it. I need to plug an arduino Uno on my motorcycle, but I dont know if it will consume too much energy and lower ...
42 views

### Where does the indicated negative voltage terminal lie on this circuit?

Does the negative voltage terminal lie after the 150v source ?
99 views

### How to extract energy from an alternating electric field?

Given an alternating electric field E inside e.g. a big parallel plates capacitor, how can you make use of the field's energy to power an electronic device? So far I thought of putting two smaller ...
218 views

### What is the purpose of feed wire and return wire in electric railway?

Looking at the following image: Image source: The Railway Technical Website On the left of the mast there are two cables, feed wire and return wire. Are they acting like a ground cable which ...
90 views

### Supercapacitor electric model

I am doing a dissertation in Electrical and Computer Engineer which involves supercapacitors. I read the norm IEC/EN 62391–1 and the 60384-1 but still I don't have a clear answer for what's the ...
593 views

### Capacitors in parallel with voltage sources

Why can't capacitors be connected in parallel with ideal voltage sources? In various questions involving it we were asked to ignore the capacitors, by our teachers without valid explanations.
103 views

### Network Theorems on DC and AC

Are network theorems (KVL, KCL, Thevenin, Norton, Superposition, Max Power Transfer) applicable on both DC and AC networks
376 views

### Where do I connect the negative and positive wires on this motor

Pulled a motor from a broken frother and accidently broke the connections and would like to turn it into a hand crank generator for fun Thanks here's a photo Apparently this is a rotor not a motor. ...
44 views

### State estimation in power system [closed]

Regarding state estimation in electrical power grid, does the voltage phasor magnitude at each bus(P-Q bus and P-V bus) considered as a static state variable or a dynamic state? I am a little bit ...
341 views

### What will happen if a dependent voltage source in parallel with a dependent current source?

What will happen if a dependent voltage source in parallel with a dependent current source. like dependent voltage source: 4Vx and current source 3Ix in parallel.
119 views

### Electrical panel indicator lights flickering [duplicate]

I'm wondering what the underlying mechanism of the flickering of the panel indicator lights is. Are there electronic oscillators of some kind in there?
153 views

### Current waveform electric motor

Does electric motor reactance at given speed is constant according to rotor position (angle)? For switched reluctance it is not. But for three phase induction motor? Considering there is no any noise....
609 views

### Reversing Motor with 2 push button switches [closed]

i wanted to make a schematic to reverse the motor direction with 2 push buttons, and i failed every time to make a schematic like this, when someone can help me would it be helpful thanks.
244 views

### What is the connection of this synchronous motor?

so yeah I took this picture of the terminal box of the synchronous motor we're cleaning. I can't distinguish what is wye or delta when it's shown like this. what are the indications that a connection ...
345 views

### Does an AC electric motor with no load consistently draw its maximum power at full RPM's?

Say you have a typical bench AC electric motor rated at 180W which has reached its maximum RPM's. Does the motor always draw 180W when running at full RPM's ? Or does the motor draw less power once ...
1k views

### What determines the voltage of an electric motor?

What determines the operating voltage of an electric motor? And could an AC motor be run at a lower voltage (i.e. 80v) and how? I'm not sure if its the windings turns or thickness of the wires which ...
739 views

### TT Earthing System [closed]

Ok guys I can't just understand a thing of the TT Earthing System, why on it the ground of the power cabin is connected to the neutral of the power cabin?
113 views

### Can 2 9v batteries heat an electric range heating element

For an experiment I am trying to power the heating element in the link attached. http://www.appliancepartspros.com/frigidaire-range-surface-element-316442300-ap4356466.html My goal is to power it ...
261 views

### How do I stop excess PAM8403 distortions?

I have a pam8403 amp that's exactly like this one. It is connected to my raspberry pi zero gpio pin which outputs 8 bit pwm signal for sound. When I play a sound, I can hear it from my 3 watts 8 ohms ...
1k views

### I don't understand clearly why the ideal sources that the value doesn't match can't be connected

I'm studying recently Electric Circuits (9th edition) by Nilsson. In Chapter 2, an example bothers me. simulate this circuit – Schematic created using CircuitLab I don't understand why these ...
70 views

### Energies of the fields in a plane wave, attenuated and unattenuated

This is a combination of two of my previous questions (question 1 and question 2) which are related. I'm trying to learn both how energy is carried in the electric and magnetic components of a plane ...
88 views

### Energies carried by electric and magnetic fields in plane waves

This is a newbie question. I'm trying to understand what I think must be a very basic concept with an obvious answer, but I want to be sure. Do plane wave electric and magnetic fields of equal ...
68 views

### The electric and magnetic components of far field EMR and shielding thereof

This is a newbie question. I'm pretty sure of the answer, but I would like confirmation. I found this thread in this forum that came close to what I was looking for, but I think my question is ...
245 views

### super capacitors for dummies! [closed]

What is the consensus on using super capacitors to power a 500w electric bike motor? Cheap and innovative alternative to li-po batteries, or explosion between thighs waiting to happen? The plan is ...
471 views

### Actual electric potential at terminals of battery

I understand that a 9V battery will produce an electrical potential difference/voltage of 9v across the positive and negative terminal, with the positive terminal having the higher potential by ...
10k views

### Electric wiring color codes: BROWN, BLUE and BLACK

31.01.2018 16:40 start / Thank you all for the answers, because this is not a standard wiring plug, i need assistance wiing the wifi adapter in the middle of cable which connect the energy master ...
56 views

### Input voltage drop [closed]

I have a circuit, the characteristic of the load is unknown, most probably resistance and capacitance, the input for the circuit is %v and frequency is varying from 10 Hz to 30 MHz. once the input ...
474 views

### Efficient 60v to 12v DC-DC

I'm on the process of building a new version of my ebike electronic systems and I'm searching for a way to lower the voltage of the battery (13s = 54,6v fully charged) to 12v/5v for the accessories ...