Engineering product survey

[paindoc]

So yeah, for engineering we have to run a survey to justify our chosen project.

We have chosen to build an improved micro fridge, since most current ones suck. Ours will use a peltier module controlled by PWM, better insulation, the ability to heat and cool, and hopefully will actually be able to hold and display the temperature of an object inside, material costs depending.

Sounds like a dumb project but there are worse ones in our class, somehow.

The survey is here [url]https://www.surveymonkey.com/s/KJSLZQJ[/url]

Its only ten questions long and is pretty easy to fill out. The more responses we get, the better. The more people who would like this product, the better.

Thanks guys

[editline]4th December 2013[/editline]

also suggestions for the survey and the product are appreciated as well

[S31-Syntax]

Done.

Frankly I'd love a micro-fridge. Hold like, 5 cans or bottles or whatever.
I have no fucking clue how you'd pull off effective heating [I]or[/I] cooling with USB, but sure why not?

[editline]4th December 2013[/editline]

Also if its USB I want firmware documentation. I'd [I]love[/I] to be able to control it PC side.

[editline]4th December 2013[/editline]

Suddenly relevant
[img]http://imgs.xkcd.com/comics/surgery.png[/img]

[Angus725]

Micro-fridge isn't a Mini-fridge right?

On a side note, Pain, what's your degree in?

[sloppy_joes]

[QUOTE=Angus725;43069541]Micro-fridge isn't a Mini-fridge right?

On a side note, Pain, what's your degree in?[/QUOTE]

He's probably a first year engineer doing a first year engineering design course.

[Thelurker1234]

It'd be great if it had a traditional plug option as well, my USB slots are usually cramped

[Haskell]

I've done your damn survey for you.

[ramirez!]

Aren't USBs limited to 5v/500mA draw? That's gonna be one hell of a challenge.

[S31-Syntax]

[QUOTE=ramirez!;43070753]Aren't USBs limited to 5v/500mA draw? That's gonna be one hell of a challenge.[/QUOTE]

There [I]are[/I] USB mini fridges... but they don't also warm from what I've seen and I have no clue how they perform.

[paindoc]

We're using a Peltier module to cool or warm the inside. Most current ones are just bare plates or closable fridges with little to no insulation so they don't hold heat worth a damn. Getting a peltier to heat or cool can be as simple as flicking a switch, and they come in various models for various needs; including different power needs so we will see what we can do on that front.

The biggest constraint won't be voltage- plenty of sub-5v peltiers exist from what I've seen in my research so far, but it is finding a peltier that works well on low current that is going to be interesting.

As for temperature control and such, we will have to see how easy it is to integrate an arduino since I know for a fact peltiers can be controlled by PWM and a thermistor, and I've had a bit of experience working with that on my 3d printer

Also, I'm not a uni student. This is my 4th year high school engineering project. I plan to get a degree in Aerospace Engineering from University of Washington, so thats why I took engineering in high school.

Thanks for the responses so far guys, makes my work much easier.

And syntax; If we manage to integrate a heating-cooling solution and temperature control through arduino the firmware would absolutely be open. probably won't end up creating more than a few prototypes, but we could sell those and give the money back to engineering or a charity of the buyers choice or something.

[editline]4th December 2013[/editline]

also since its usb it can be easily run off a wall plug. Hell, we may end up making it so that it only reaches full cooling when plugged into the wall at this rate... :c

[Penguiin]

[QUOTE=paindoc;43072056]We're using a Peltier module to cool or warm the inside. Most current ones are just bare plates or closable fridges with little to no insulation so they don't hold heat worth a damn. Getting a peltier to heat or cool can be as simple as flicking a switch, and they come in various models for various needs; including different power needs so we will see what we can do on that front.

The biggest constraint won't be voltage- plenty of sub-5v peltiers exist from what I've seen in my research so far, but it is finding a peltier that works well on low current that is going to be interesting.

As for temperature control and such, we will have to see how easy it is to integrate an arduino since I know for a fact peltiers can be controlled by PWM and a thermistor, and I've had a bit of experience working with that on my 3d printer

Also, I'm not a uni student. This is my 4th year high school engineering project. I plan to get a degree in Aerospace Engineering from University of Washington, so thats why I took engineering in high school.

Thanks for the responses so far guys, makes my work much easier.

And syntax; If we manage to integrate a heating-cooling solution and temperature control through arduino the firmware would absolutely be open. probably won't end up creating more than a few prototypes, but we could sell those and give the money back to engineering or a charity of the buyers choice or something.

[editline]4th December 2013[/editline]

also since its usb it can be easily run off a wall plug. Hell, we may end up making it so that it only reaches full cooling when plugged into the wall at this rate... :c[/QUOTE]

ditch the USB idea altogether unless you need it to talk to the computer. even then, I'd go bluetooth with a normal power supply (like a printer power supply, lots of watts DC). USB is [B]not[/B] designed for stuff that just needs power. that's why any time you see one of those shitty ass USB powered mini devices it's always made in china. USB devices before they receive any power have to first communicate with the power distribution chip or whatever the fuck it is to say "hey I need 150 mA and I'm a keyboard" or whatever. that's why if you plug an iphone into a computer it won't charge right away even if you have the drivers installed; it needs to safely and intelligently allocate the power... otherwise why not just use a power supply if you just need simple power? . I have been told it's very bad practice to just tap the power rails because the computer is just missing current and it doesn't know why. this can lead to bad shit happening in the power supply/power regulation components of your computer and even if it doesn't you're not going to power shit with 5V/.5A (2.5 watts... nothing)

if it were me I'd spend the bulk of the budget on insulation because 1% more efficiency is 1% less current needed. and, I would focus on just trying to make it a fridge. if you could make it cool stuff quickly and even be able to freeze that would be amazing forget heating IMO

[OogalaBoogal]

[QUOTE=ramirez!;43070753]Aren't USBs limited to 5v/500mA draw? That's gonna be one hell of a challenge.[/QUOTE]

They can do 5V/5A if you give them enough juice in charging mode.

[BiN4RY]

[QUOTE=OogalaBoogal;43073188]They can do 5V/5A if you give them enough juice in charging mode.[/QUOTE]

5v at 5A is still nowhere enough power to efficiently drive any sort of heat pump. A peltier is used in low performance minifridges, and even those typically requires more than a hundred watts of power at 12v.

[paindoc]

[QUOTE=Penguiin;43072906]ditch the USB idea altogether unless you need it to talk to the computer. even then, I'd go bluetooth with a normal power supply (like a printer power supply, lots of watts DC). USB is [B]not[/B] designed for stuff that just needs power. that's why any time you see one of those shitty ass USB powered mini devices it's always made in china. USB devices before they receive any power have to first communicate with the power distribution chip or whatever the fuck it is to say "hey I need 150 mA and I'm a keyboard" or whatever. that's why if you plug an iphone into a computer it won't charge right away even if you have the drivers installed; it needs to safely and intelligently allocate the power... otherwise why not just use a power supply if you just need simple power? . I have been told it's very bad practice to just tap the power rails because the computer is just missing current and it doesn't know why. this can lead to bad shit happening in the power supply/power regulation components of your computer and even if it doesn't you're not going to power shit with 5V/.5A (2.5 watts... nothing)

if it were me I'd spend the bulk of the budget on insulation because 1% more efficiency is 1% less current needed. and, I would focus on just trying to make it a fridge. if you could make it cool stuff quickly and even be able to freeze that would be amazing forget heating IMO[/QUOTE]

Getting a peltier to switch between heating and cooling takes very little extra effort.

So far we're trying to keep it at about $30-35 since that seems what most people would pay considering it actually works. have to see what we can do for insulation

[editline]4th December 2013[/editline]

another problem is heat transfer. There isn't much contact between a soda can and whatever surface it sits on so circulating air seems to be a big deal

[kunst_deco]

Done. Personally, I'd love a micro fridge for cooling my insulin alone.

[paindoc]

[QUOTE=deckief;43074144]Done. Personally, I'd love a micro fridge for cooling my insulin alone.[/QUOTE]

oh my god you have no idea how happy this makes me. One of our ideas is to advertise this for keeping medical things in- supplies, vaccines, samples, and insulin.

Would it be alright if it was powered by a wall plug then?

[Missing User]

Done

I'm 22 and I cringed when I had to check the 13-24 box :v:

[Falubii]

[QUOTE=paindoc;43074314]oh my god you have no idea how happy this makes me. One of our ideas is to advertise this for keeping medical things in- supplies, vaccines, samples, and insulin.

Would it be alright if it was powered by a wall plug then?[/QUOTE]

As long as it doesn't freeze my insulin.

[paindoc]

[QUOTE=frozensoda;43074486]Done

I'm 22 and I cringed when I had to check the 13-24 box :v:[/QUOTE]

Yeah well we're having freshmen take this survey in our teachers first year classes, so it was a necessary evil to widen the gap a bit so they didn't feel so bad.

Should have just a put a "Freshman pleb" category or something :v:

[editline]5th December 2013[/editline]

[QUOTE=Falubii;43074964]As long as it doesn't freeze my insulin.[/QUOTE]

That would be sub-optimal I believe. Now I just need to get my dad and a few work friends to endorse it and I won't seem to have a worthless project!

[Snek]

[QUOTE=paindoc;43068762]So yeah, for engineering we have to run a survey to justify our chosen project.

We have chosen to build an improved micro fridge, since most current ones suck. Ours will use a peltier module controlled by PWM, better insulation, the ability to heat and cool, and hopefully will actually be able to hold and display the temperature of an object inside, material costs depending.

Sounds like a dumb project but there are worse ones in our class, somehow.

The survey is here [url]https://www.surveymonkey.com/s/KJSLZQJ[/url]

Its only ten questions long and is pretty easy to fill out. The more responses we get, the better. The more people who would like this product, the better.

Thanks guys

[editline]4th December 2013[/editline]

also suggestions for the survey and the product are appreciated as well[/QUOTE]

With how inefficient peltier modules are and the fact that the USB standard is 5V @ 500mA, how do you plan to design this thing?

Just curious, 'cause I considered building one myself but it turns out that most commercial coolers and minifridges utilizing peltier devices use much higher-wattage rated ones and the current market USB ones that can theoretically only draw 2.5~10W (usb2~3) don't really have any considerable cooling power to be able to cool any standard size can in a reasonable amount of time.

The current market ones aren't very well insulated and do attempt to cool a single beverage can, though, so with plenty of foam insulation and rubber gasket seals you might come out with a moderately workable (if rather inefficient) solution.

[RubberNinja]

[QUOTE=paindoc;43072056]We're using a Peltier module to cool or warm the inside. Most current ones are just bare plates or closable fridges with little to no insulation so they don't hold heat worth a damn. Getting a peltier to heat or cool can be as simple as flicking a switch, and they come in various models for various needs; including different power needs so we will see what we can do on that front.

The biggest constraint won't be voltage- plenty of sub-5v peltiers exist from what I've seen in my research so far, but it is finding a peltier that works well on low current that is going to be interesting.

As for temperature control and such, we will have to see how easy it is to integrate an arduino since I know for a fact peltiers can be controlled by PWM and a thermistor, and I've had a bit of experience working with that on my 3d printer

Also, I'm not a uni student. This is my 4th year high school engineering project. I plan to get a degree in Aerospace Engineering from University of Washington, so thats why I took engineering in high school.

Thanks for the responses so far guys, makes my work much easier.

And syntax; If we manage to integrate a heating-cooling solution and temperature control through arduino the firmware would absolutely be open. probably won't end up creating more than a few prototypes, but we could sell those and give the money back to engineering or a charity of the buyers choice or something.

[editline]4th December 2013[/editline]

also since its usb it can be easily run off a wall plug. Hell, we may end up making it so that it only reaches full cooling when plugged into the wall at this rate... :c[/QUOTE]

This wouldn't happen to be a Project Lead The Way developed course, would it? I took a course my high school senior year called EDD: Engineering Design and Development. It was the capstone course where we basically did the exact same thing you're doing now.

I filled out your survey. I had a tough time coming up with survey takers when I did my project; can't believe I didn't think about opening it up to the internet to help. Hope you do better than my partner and I did.

[paindoc]

[QUOTE=RubberNinja;43081463]This wouldn't happen to be a Project Lead The Way developed course, would it? I took a course my high school senior year called EDD: Engineering Design and Development. It was the capstone course where we basically did the exact same thing you're doing now.

I filled out your survey. I had a tough time coming up with survey takers when I did my project; can't believe I didn't think about opening it up to the internet to help. Hope you do better than my partner and I did.[/QUOTE]

Thanks. Yes, it is a PLTW EDD capstone course. I do hope we do well, regardless of our pretty stupid design.

We started out quite well but thanks to the wonders of democracy and practicality we dropped in prestige and worth considerably. We went from a 3D printer design (no one except Pew in our group of 4 was interested), groups split into 2 and 2, we thought of a quadcopter UAV to scan areas and send back a 2d map to a base station (prob. a raspberry pi, usable for mining, police, and military). Groups joined back together and we did a vote with everyone ranking their top 3 favorites.

The USB fridge was mostly a joke by me for a project I would someday find amusing to work on. I put it as my first because I thought no one else would vote for it and didn't want to swing the vote to my 3 previous ideas and leave the path open for others' ideas.

but somehow

the USB fridge won in a landslide.

[fenwick]

[QUOTE=paindoc;43083389]Thanks. Yes, it is a PLTW EDD capstone course. I do hope we do well, regardless of our pretty stupid design.

We started out quite well but thanks to the wonders of democracy and practicality we dropped in prestige and worth considerably. We went from a 3D printer design (no one except Pew in our group of 4 was interested), groups split into 2 and 2, we thought of a quadcopter UAV to scan areas and send back a 2d map to a base station (prob. a raspberry pi, usable for mining, police, and military). Groups joined back together and we did a vote with everyone ranking their top 3 favorites.

The USB fridge was mostly a joke by me for a project I would someday find amusing to work on. I put it as my first because I thought no one else would vote for it and didn't want to swing the vote to my 3 previous ideas and leave the path open for others' ideas.

but somehow

the USB fridge won in a landslide.[/QUOTE]

Welcome to engineering collaboration.

[Rixxz2]

[QUOTE=ramirez!;43070753]Aren't USBs limited to 5v/500mA draw? That's gonna be one hell of a challenge.[/QUOTE]

But ey, that's what engineers are for