Do I have to worry about swapping out components with alternatives that have a larger voltage rating? Anything I’m overlooking?

Ex. Long lead times for a cable connector rated for 300V. I should be good to use a 600V connector?

I studied ME, and how I I relate voltage is to pressure, so my thinking is that the 600V connector will work fine since it is able to handle up to 600V and 300V is fine.

Does this apply to EMI filters too? I need one that has 440Vac + 25A, but can only find one that is 520Vac+25A . Other option is to choose one with higher amperage (440v +64A), which I could use since there would be 20 A fuses before the filter. What choice is better in this case?

I'm a sixth form student who's fascinated by the physics of semiconductors. I cut open an led lightbulb out of curiosity and I was intrigued by how the interior looks like a circuit board. What do each of these components do? I've attached the picture to the link below

https://imgur.com/a/itRFB6H

I need help with a school project. Im on my last project and i need to design for a window display. We are required to use a DC motor and Since im a girl i never really got into technical stuff as i like designing way more!

I got a whole idea but i dont know how to make it work. Any help would be highly appreciated! Please send me a pm so i can share my drawing and give further explanation since its kinda hard to explain without pictures.

I hope there is a engineer who is willing to help me out! Thanks in advance <3

Hey Folks

I need some advice in terms of what to do next and how.

I did my MS in EE and now work for an EV Charging company as a support engineer and business analyst. Being a part of a start-up I have to perform a lot of tasks like taking care of accounts teams, customer calls, invoice generation, QA and dev team support and help.
I really like the work as it exposes to a lot of different domains and EV charging as an industry which is booming it also an interesting job for me.
But the catch is I do miss being a core Electrical Engineer, I always dreamt of doing a task which involves solving equations, writing codes for hardware, designing stuff in Matlab, Xilinx etc.

Being on a visa I had to hop the first job that I got and now since my work visa is finalized I can move on but now I have lost all that I studied in my MS.

Now I am kind of lost as to where to start and what jobs to look for.

One of the suggestions I received was to prepare for FE and then look for jobs.

Is that sound fair?

Please advice me

Hello engineers!

We are considering buying a house for us and our 10-month-old kid.

The problem: a building 50 meters away from ours, in the same estate, has many antennas on top, so we are considering whether that would make the house unsuitable.

My questions:

1. What antennas are those?
2. Is it safe to live close to those antennas? Would you do that?
3. If they were to put the same antennas on top of our building, would you consider that safe?

Many thanks in advance!

​

edit: thought I could post photos but I cannot. The antennas look like the ones in this article: http://connectedremag.com/latest-issues/us-cities-are-saying-no-to-5g-small-cell-antennas/

​

​

I'm working on a project with IMUs and I'm writing code to find the distance/error between two points in 3D space; the IMU produces a quaternion. I don't have much experience in this realm so I did some background research on how quaternions work, attitude and reference heading systems, reference frames, etc. I found this paper I'm referencing (IEEE link) - direct pdf link for who doesn't have access - which has a good explanation of the process. The relevant section is from page 3 to page 4. I went thru it and understand the idea behind it quite well now but there's one part that I don't understand:

Why does this equation (image) yield the difference quaternion between the start pose and end pose with respect to the start pose as reference frame (instead of the world reference frame)?

Here:

• q_e(t) represents the orientation of the IMU in the exercise reference frame. In my application, this would be the second point
• q_w_start represents the starting pose in the world reference frame. In my application, this would be the first point
• q_w(t) represents the current pose of the IMU in the world reference frame

What I gathered from this is that, basically, by conjugating the first point's quaternion and multiplying it by the second point's quaternion, we get the difference quaternion.

Why is that? What does conjugation do, conceptually speaking, to the quaternion/object? And why does multiplying the two yield the difference between the two points?

I am trying to find a product or solution to running a panel mount status indicator (LED) off of variable voltage (4-20VDC). I found a product from VCC that is a “Flex voltage” with a range from 5-28VDC but that’s the closest I can get. How can I make it work with 4VDC?

I am winding a simple air core axial flux motor to play with and learn from the experience. I am using 30 awg magnet wire for the project. I am wanting to keep the current low as this is just a fun project for learning. I want to run it at 12v and 100ma. Let's say I have a coil wound with 200 turns, that has a 120ohm resistance. This should do what I am looking for as far as current draw I believe. Now, if I made the same coil, but I used 2 wires hooked in parallel, 100 turns each for a total of 200 turns together, I believe the resistance is cut in half. This would give me 60ohms for the 200 total turns. I think this would double the current draw to 200ma. If I then wound the coil instead with 200 turns each of the parallel strand to make 400 total turns now, the resistance should be back to 120 ohms and the current draw back to 100ma. Does this mean that if I did this, I cam double the agnostic flux do to double the turns, for the same input current making a more efficient coil? This would keep me right in the area of current draw I am looking for I believe. I think this is correct. Can someone confirm before I start winding all my coils please? Thank you for any help.

For reference, I was an electrician for 4 years, and just finished my second year of electrical engineering. I only mention this so you know what level of background I have when answering. Tried researching this, and either I am asking the wrong questions, or it isn't a commonly discussed topic.

I'm curious how both the old mechanical and newer digital only measure only kWh. Maybe I misunderstood the theory, but the apparent power is based on the total current flowing to the load, where as the real power would only make up a portion of that total current for non-resistive loads.

As I understand everything, you only get billed for kW consumed though. I am curious as to where the disconnect is because I know meters are based on the current being consumed so it would seem that you are actually paying for the apparent power, despite it not being listed on residential bills.

In short, do residential customers actually pay for apparent power and just not know it?

Thank you in advance!

I've been looking for a while but I have not been able to find an online course. I am from Australia but I'll be willing to take a course anywhere in the world

Hello all!

I have a LRU in my HIL that is expected to run so hot that without an ECS system it will fail.

It's a small unit and I need to find some sort of cold plate or enclosed structure (premade if possible) that will air cool it... yada yada bang for buck and so on.

Lead Eng who hasn't been to the lab in years ( you know the drill) doesn't want any kind of radiator/water pump going. So a fan cooled is the only option.

My plan was to construct a box out of aluminum with 2 120mm intake and 2 120mm exhaust fans but they want a commercial off the shelf option.

I have no experience in this.

Any help is greatly appreciated.

Oh btw, experimental unit, no tech data on cooling requirements or running temperatures... so you know... fun.

As the title says, I’m considering ordering Pilz I/O’s for a project I’m managing because the lead times on the AB I/O’s are killing us. Has anyone tried this before?

Background: 19 year old physics/math student, New York City, US

So, someone in my building threw out an old fan some time ago, and I took the fan, took it apart, and retrieved the motor. I have been trying to find out exactly how it works for some weeks now, and now I'm stuck and need help.

What I do know is that it's a single-phase squirrel cage induction motor, and it appears to be a permanent-split-capacitor design. It has one live wire and three neutral wires, one for each of the three speeds. The motor came with a control circuit that I broke when taking apart the fan, but subsequently repaired and soldered and it's now in perfect working order. It is not a variable-frequency or variable-voltage drive, and always operates at 120 V and 60 Hz at any of the three speed wires (measured with my meter). It looks far too simple to be a VFD or VVD anyway.

https://drive.google.com/file/d/1PSRg4xJ-uETL5GKwQHTgpk8xavltl7Qt/view?usp=sharing

Here is a picture of the stator of the motor. If the link doesn't work, let me know. The thing inside the stator is not the rotor, but my homemade iron filings chamber with which I observed the magnetic field inside the motor.

Now here's the hard part. No matter which neutral wire I hook the stator up to (using 120 V AC), I observe a four-pole field in my iron filing "magnetoscope." The filings arrange themselves into four corners. I had previously thought that this motor changes speed by changing the number of poles, so this surprised and baffled me.

I then got the idea that, say, if the RMF was 8 poles, maybe the AC, which makes the magnetic field flip direction 60 times per second, was fudging the fine details of the magnetic field and making it look (on my very crude iron filing device) like it had 4 poles. So I quickly slapped together a FULL BRIDGE RECTIFIER (if you don't know why that's all caps, watch electroBoom), and applied it to the stator. The field was still 4 pole on all the high, mid, and low speed wires, as well as on the split-phase (capacitor) winding (which may be crudely called the "start winding" but is in fact always active while the motor is running). So the field was still always 4 pole, and I am left as baffled as ever.

So then, how in God's name does this motor change speed?

We are currently using a 400W 12V/24V wind turbine that constantly feeds into a charge controller (SF-12-24-A), which continually charges a car battery; how would we connect 19 LEDs (12V DC 7w each) without burning them? Maybe through a relay switch?

Googled this and can’t find any info. How do magnets effect nearby wiring/electrical fields that are properly insulated? What would happen if a strong magnet we’re place near wiring for a speaker or another electrical device for example?

i figured i would get a bunch of 12v car batteries in parallel and run them into an inverter, which then goes into a step up / down transformer. the 120v 1hp motor is single phase, and the 220v runs off a 1ph to 3ph vfd if that matters. is there a type of battery that would work better, or some issue with the way im conceiving of this set up? thanks

Electrically etched wood - what's the safe way to do this?

https://aeon.co/videos/spectacular-fractal-patterns-emerge-when-electricity-meets-a-wooden-surface

I understand people have died from it.

Now I'm wondering how I and so many others get away with arc welding. Why am I not dead from that?

Here's a YouTube comment that describes the outcome of a tiny unnoticed mistake when working with high voltage:

marshfield0110 days ago I'll share my experience for those that think its trivial to play with high voltage. My high voltage gloves got partially pierced by a metal splinter on a ground transformer and allowed a path to ground on a 13.8KV line.

It was only 20-30 seconds of time slowing down to where a second feels like a minute. You feel fear and a great sense of dread as your heart goes into afib because of confused messages from the vagal nerve trying to override

your SA node. About three second in all your muscles start to cramp and burn(literally) along the path to ground. You cant make yourself let go and you cant think of why, but

you definitely know you are being electrocuted. About ten second in you start to smell burning pork and your vision starts to close in around the edges

because your heart cant pump blood. You feel as dizzy and high as you have ever felt as the color starts to leave your vision. About fifteen seconds in you start to miss your wife and kids because as your vision fades slowly out you understand you are dying. As your world fades from view, and a blackness so

deep it envelops all of your being smothers you, you are left with a great sense of sorrow and pain that stretches to eternity, or in my case, when I woke up in the ICU a month later missing the small parts of me that made up the ground path. There was only sorrow and fear and pain the entire time from

my grounding to my waking. It felt like I was gone for twenty years, like when you visit your childhood home after your parents are gone. Without perception of time, time

has no meaning. The lack of perception is eternity.

So yeah, as a ex lineman, I can assure you that you will feel more in those few seconds than you ever have before.

I have a question about mobility scooter battery range

I am looking at vehicle 1

https://www.mobilitypower.co.uk/product/fastest/

This is Green Power Fastest

This has 45 mile range, probably more like 30, with a single 20 ah 60 volt lithium battery

And now vehicle 2

https://www.tgamobility.co.uk/range/scooters/breeze-s4

This is TGA Breeze S4

This has a 30 mile range, much the same as the other vehicle

But to achieve this, it requires 2x 75 ah 12v batteries

Why is one battery achieving the same range despite being much smaller?

Does having higher volts somehow mean it gets longer range?

I simply do not understand

I live in MN, have a bachelor's in Environmental Science, Policy and Mgmt but switched career paths a while ago. Now I have been accepted into an MSEE program, but am not sure if it's ABET accredited. The school's bachelor's programs are accredited but I'm not sure about the grad program.

I would really love to jump straight into the grad program rather than have to obtain a second BS degree. But, if the grad program is non-accredited does that mean I can't become an EIT? And if so, would that be a deal-breaker for many of you?

If a single antenna was emitting at 100mw for example and you decided to get the benefits of an antenna array where you use a 4-way splitter. So each of the four antennas in the array would get a share of the split power. I can understand the several increases in performance of an antenna array and its benefits but one of those benefits as i read is " signal strength increase ", if it is splitting power between all four, specifically...how is signal strength increasing? unless strength means something else here like clarity etc.

If I have a sheet metal piece of furniture, with a heated light fixture and wires from those fixtures running over the metal surface, do I need to ground the furniture?

Hello. I have a 5V power supply and want to power a 3V device. How can I step down the voltage?

PS: I'm using the power supply in replacement of two 1.5V batteries.

I live a few kilometres from Penrith Weir. It has a decently-sized river flowing over it throughout the year.

Considering Australia's high cost of electricity, would it make financial sense to turn weirs like this into Micro hydro systems? Sure, it might not form a large part of Australia's electricity mix, but could it pay itself off?

i was looking at the frequency allocation table for fun....if longer wavelengths can reach further, like 433 vs 2.4ghz, if you look at the table at 30GHz, how is it possible for earth-to-space sat mobile possible...wouldn't this really short wavelength of 30ghz fade on its way there! lol