#and I am in engineering for physics

[imhereonthekitchenfloor]

Plot twist: local biomedical engineer's least favorite science field is biology. (This makes a lot of sense you just don't see how)

[strawberrybyers]

stranger things broadcast channel… count your days fr do not play games with me because immediately my brain went to: THIS IS A HINT THAT WILL IS STAYING AT MIKE’S HOUSE BECAUSE HE DOESN’T HAVE A HOME.

WILL AND MIKE SHARING A BEDROOM TRUTHERS RISE 🧎‍♀️🧎‍♀️🧎‍♀️🧍‍♀️🧍‍♀️🧍‍♀️

[quartzdecay]

I have a request for people with experience with wheelchairs, if you personally use/used them or have people in your life that do: PLEASE COMPLAIN ABOUT THEM TO ME! TELL ME ABOUT THE WAYS IN WHICH THEY CAN SUCK! IN GENERAL OR SPECIFICS!

I need this information for a project I'm doing in my design class, wherein my group is going to attempt to prototype a wheelchair with both offroad and indoor capabilities, per say, that is still reasonably light and inexpensive. I'm asking this of you all on tumblr because to begin our project, we need to familiarize ourselves with the nature of this problem. We want our solution to actually be made with the opinions of wheelchair users in mind. I would be incredibly grateful if anyone could reblog or comment with any gripes they have about wheelchairs, especially in relation to their maneuverability, but anything works! Thank you so much for your time!

[bidoofenergy]

to @riceofthepuffedvariety who requested jimmy/tango and magical realism AU. for @mcyt-drabble-exchange

Don't tell Grian, but Jimmy's favorite part of the day is when a certain customer sweeps into their cafe. He never shows up at the same time but always in the same way: disheveled, squinting against the sunlight, redstone smudged into his clothes, heavy gloves tucked into his back pocket.

Tango stares up at the menu. Jimmy desperately tries not to seem nervous. He fails miserably, wings smacking into Grian despite his attempts to settle them against his back.

Tango steps up to the register and grins up at Jimmy, all sharp teeth and candlelight hair, and says, “Hi Rancher,”

[cillyscribbles]

every time i talk to someone who's not yet gone to uni about uni i sound like i'm getting paid to do an advertisement and it's a bit of a problem for me because . i genuinely love uni so much. i want everyone who goes to uni to enjoy it as much as i do (improbable but you can start by picking something you actually Want to learn about) but any authority i have on such is likely ruined a little bit by the fact that i can be an obnoxiously positive person. which results in me sounding like a shill. which i am not . i just love uni

[spark-hearts2]

tell me everything about AC to DC filters Right Now

:0

Dear god.

OK I have to make some assumptions or else this is going to get really long. I am going to assume that you already know what AC and DC are. I am going to assume that you took (and passed) geometry, so a sine wave and it's variations are familiar to you. I am also going to assume that you also know the difference between voltage, current, and resistance.

So, what are AC to DC, why do we care about that? Well, the electricity coming out of the wall is AC, but in order to, lets say, charge your laptop battery, you need DC. In fact, if you look at a laptop charger, you'll see The Brick. The thick rectangle that gets hot when charging the laptop.

THAT'S THE AC TO DC CONVERTER

I just called it converter instead of filter. Why? Because filters technically only remove a 'ripple' from DC current, so a current that's almost DC but not quite. If you are making the entire jump from AC to DC, then that's called a converter.

Now here's where things get fucked.

These are all of the parts after the plug. The load is your laptop, the regulator is your filter.

Let's say that this is your AC signal (this graph showing the voltage over time). Now, the first thing this passes through is the transformer, which only adjusts the voltage to the correct level. Some devices need it higher, some lower. Let's say that this transformer is a step up transformer, because it made the signal bigger.

The next step is the rectifier. Now, traditionally this part is taught in stages in order to show it's affect on the signal. I'm going to speed run that. I will assume that you're familiar with what a diode is. If you aren't, just know that it only allows current to flow in one direction. So, anything going backwards will be removed. Picture a one way valve.

So, if we were to send this signal through one diode, then that would leave us with

just the positive half! That's why this setup is called a Half-wave rectifier.

But what if we were to use two diodes. As in, fill in the blank spot that the negative half left with another positive bump. That would give us

This lovely thing! Which is great, but it requires another AC signal that is 180 degrees off from the original one in order to exist. Which, transformers exist which can provide that, but it's not cost effective. So, that leaves us with the most common setup, the Bridge Rectifier.

I've been skipping the circuit diagram so far, but now it's important.

THIS thing is a bridge rectifier connected to the transformer (yes that's what transformers look like according to circuit diagram shorthand). Now, I am American, and for some reason American electricians use that up and down sharp thing in the middle of the diamond to indicate a resistor. Europe uses a rectangle. Again, I am going to assume that you know what a resistor does.

Those four black triangles with lines? Those are diodes. The line across the tip of the triangle indicates what direction they are allowing current to flow into. Now picture you were a positive signal flowing in through point A into the bridge. There's a split in the circuit, but one way (diode D4) is blocked, so you have to go across diode D1. Now you're at the edge of the diamond, once again two ways you can go. You head towards diode D2, because diode D3 won't let you through. What that looks like is this

What about the other direction? Well that looks like

Notice that the edges of the diamond are called out? Points C and D. That's the money makers. You see, if you plug into point D as your positive and C as your negative, you get a full wave signal! (so sorry for not going fully in depth on why that works just trust me it's a bit of a mess and should really be taught with the actual circuit in front of you, not across the internet like this)

A full wave signal is completely positive, but it's not exactly DC yet. That's where smoothing comes in. This is done with a capacitor!

The capacitor is charged up and then slowly releases it's charge. But before it can completely discharge, it gets recharged by the next wave. Quick review, a capacitor is like a battery where it can be charged up, but unlike a battery which holds charge with chemistry, capacitors hold charge with physics. They can still wear out, but not nearly as quickly as a battery.

What does that red line look like? Well, almost like a straight line, except it has RIPPLES! That's right, we're finally back to the filter! Or the regulator as the diagram calls it. Means the same thing.

Sometimes, this step is skipped. If the device getting signal isn't too sensitive or it's just cheep, then the electricity stays bouncy. Some devices really care about any fluxuation in the signal, in which case they get a big expensive filter.

Unfortunately, the inner bits of a filter are many, so I won't be going into all of that. But you want me to go into that, so I will show a circuit diagram.

This is a diagram of the ADP1612

This website has a downloadable version of the spec sheet!

But that's a level of detail that you usually only get into if you are planning on building a circuit. The day that you're flipping through spec sheets in order to check compatibility is when you've really become an engineer.

So that's how you go from AC into DC. Yes, I just spent an hour typing this all out. I like electricity a lot.

Here's a GREAT video that goes over all of this but the guy actually has a circuit and an ossiliscope in front of him to show the signal.

[mycological-mariner]

Cool so I get to start training in a forge and welding and steam engine maintenance and fitting on weekends

[grimmjowjaegerjaquez]

whenever i more solidly get into doll customizing im gonna take one of these mh dolls and turn em into soren

[prac-ticalproblems]

[dkettchen]

My most male trait is the "ye I can do that" attitude abt stuff I have no means of actually knowing whether I can do

[immortalsins]

the way i'm at my mental and physical limit rn but i'm probably never going to use this degree as intended . :\

[rooksunday]

wild to me how the noise of a lorry's engine idling while they offload goods to the shop next door doesn't make everyone else in hearing range want to scream, cry, throw up, and eviscerate everyone responsible for creating said noise for every agoninsing second of the excruitiating twenty minutes (objective)/four hundred years (subjective) aforementioned offloading takes. what must that existence be like for people. i imagine it is beautiful.

[twojstarywiniary-ofiszal]

My shittily done door accidentally recreated "The Double-Slit Experiment" except with just one slit??¿??‽

Huh‽

[intrinsically-disordered-proxein]

fuck zodiac signs whats your favourite nonsingular orbit of a swinging atwood machine

[yesterdaysnewts]

brainrot so bad ive thumbnailed a nine page comic of a silly warrior cats au thing

[t3chborb]

I don't consider Ramattra difficult to draw, just very time consuming due to all the details.

... Excluding his ELBOWS, of all things.

Try extending your own arm and twisting your wrist and then entire arm. How in God's name do those kinds of motions (or in my case, poses) translate to a robot arm without a ball joint at the elbow???? I swear whenever I pose my arms to get a better idea on where the elbow itself points, which side of the hand has the the thumb, etc etc, then translate the information onto him, 99% of the time he ends up with dislocated elbows...