Proof of Perpetual motion? Answered

I am sorry I can't embed the video but you can find it on Youtube here  proof? :-)

Question by rickharris   |  last reply


Does any one know how i may make a waterproof webcam i want to study my fish from inside the tank

Topic by TT__TT   |  last reply

Where can I get reinforced graphene to make bullet proof aromor? Answered

Where can I get reinforced graphene for bullet proof armor? I live in McAllen Texas. I'm trying to get a type of graphene that is stronger than steel, but I'm not sure if I'm suppose to get reinforced graphene plastic or some other type, don't even know the names and differentions.

Question by Anti11   |  last reply

water proofing a Garmin 765t for motorcycle usage?

Garmin 765T GPS Has anyone attempted to make one of these units suitable for use on a motorcycle ? This would entail a waterproof mount of some description and address any issues with over heating

Question by teppy dumppy   |  last reply

How can I make a fire proof hiding safe for cash - the size of a toilet paper tube.?

I have some cash that I want to keep in my house - emergency fund - but I worry about two things - theft & fire. Any ideas of something that won't burn up in a house fire that small? What usually survives house fires?

Question by karrel   |  last reply

What is in a gel sac? Would it be any good at sound proofing? Answered

So yeah, I was thinking about making a sound-proof box as part of a project and wondered: would a gel sac make good sound insulating material.  You know the stuff I mean - the little sac like things you can't help but prod about on posh mouse mats and on gel bike saddles.  Thinking about that I also realised I didn't really know what the 'gel' material actually is?  Is it possible to easily make a similar or substitute substance at home?  Thanks.

Question by bongodrummer   |  last reply

query about soundproofing

Hey, What would be the best commonly available material to soundproof a small device? Sam

Topic by sam noyoun   |  last reply

trying to make a simple motion sensor to be fitted on a car wheel ?

I'm trying to make a very simple motion sensor which will turn on and off a few LED lights with the movement of the car wheel, the only tough part is it needs to be installed inside a cars wheel cap and i can only use salvaged parts. i need to make it waterproof and shock proof too so that the parts don't just fall off if the car is moving at a high speed...

Question by randomizator   |  last reply

What flexible rubber can i use that will stick to ceramic to make it shock proof?

When the ceramic is broken it does not fall apart completely because its bonded with rubber

Question by abigailjade   |  last reply

How to Waterproof a DC motor easily?

Hellow Everyone!! I'm trying to build a ROV and bought 3 DC motors for that. I want to waterproof them. Please give me some general Ideas to waterproof them.

Question by sarveshk   |  last reply

Help with capacitor basics? (the math part) [ANSWERED. Come here for the proof if you want it!] Answered

I understand the operation for capacitors, which make a lot of intuitive sense to me, and seems deceptively simple. I know that the derivative  of the voltage across a capacitor (the slew rate, if you will) is proportional to the current, for a given capacitance. So when the voltage is not changing much, like when it is connected across power supply rails, and the capacitor has little-to-no current flowing through it, and it appears as a high impedance. Fair enough. And when I am winding up the wick on the constant-voltage power supply, so that the slew rate is constant, and the voltage is changing at a constant rate, the current will be relative to how fast that voltage rising/falling. Again, that makes sense. I have proven that to myself time and time again. The technical math way of showing all that is this:          dV/dT * C = I or with units plugged in: d(volts)/d(seconds) * Farads = Amps (or something like that)   Likewise, I know that I can do things in reverse, and that forcing a controlled current through the capacitor, that the slew rate of the voltage across the capacitor will be proportional to that. In other words; the voltage will be integrated over time (as it steadily rises or falls). I do not like integrals in math (esp. when they require by parts or partial fractions!), but the concepts do come in handy in practical design! This is also my 2nd favorite way of imagining what an integral are! (My favorite is actually the water cup or well analogy, where a water faucet or hose is a function, and a the level of water in the cup, pool, well, etc. is the integrated result. That makes the function of integrals really clear and deceptively easy LOL!) So, I basicly have been trying to figure out how to take these simple, easy-to-understand relationships, and take ohms law, and have a super basic RC circuit, with 5V, 5 ohms, and 0.1F. I have so far figured out how to take ohms law, substitute I in the capacitor formula, and get a function. HOWEVER, this is where I get stuck. -------------------------------------------------------------------------------------------------------- Here is the circuit:            +5V---(V2)-----/\/\/\/\/\/----(V1)-----| |-------0v----(grd) So after having a bit of a think, I have figured out that I really need to account for 2 different V's. The 5V power supply, V2, and the voltage across the capacitor, V2. I know that the current flowing through everything in a series circuit is the same, so then I can easily figure out current by calculating the voltage drop across the resistor which is this:            I = (V2 - V1) / R  So now, lets plug that into the mysterious capacitor derivative thingy: (All I did was substitute the I in the capacitor formula with the that ohms law formula above.)           dV(1)/dT * C = (V(2) - V(1) ) / R. -------------------------------------------------- Now, I just plug in the values, and simplify as much as I can, to make it more friendly to my eyes. C = 0.1F, and R = 5 in my case, since I am using a 5 ohm resistor, 100mF capacitor, and I know V2 = 5V, since that is the output of a 7805 voltage reg.           d(V(1))/dT * 0.1F = (5V - V(1) ) / 5ohms. That dV/dT is a bit hard to look at, so I will use V prime, or V' to represent that instead:          V(1)' * 0.1 = (5 - V(1)) / 5 I do not know how to simplify that further though, to end up with that weird inverse exponential curve that is the time constant thingy, with that decaying charging curve. I have V on one side, and V' on the other side. :( So this is how far I got:        5 + (1/2 * V(1)') = V(1) EDIT: I HAVE ADDED THE PROOF HERE IF YOU WANT IT

Question by -max-   |  last reply

how to make electric r/c boat?

I want to make a boat for school with an electric powered battery motor with a switch, which can drive a propeller in the water. it must be water proofe but if it cant anything as close as possible.

Question by    |  last reply

How do i build a weatherproof, dust proof video projector enclosure with good airflow for use in a desert enviroment?

I'm going to be using a projector in the desert at night and need to build an enclosure for it. The enclosure will have to have a serious filtering system to keep blowing sand and dust out, it also will have to be able to block any rain that just might fall. While doing all that it must push alot of air out of the box to keep the projector cool enough. It does NOT need climate control because the desert gets really cool at night when ill be using this unit. Ideas?

Question by    |  last reply

Lm3914 battery level indicator 1v - 40volts?

So I looked up peoples ideas off of here and google I set it up the exact same way I must be missing a step can someone please dummy proof this for me.

Question by dominick.j.pezza   |  last reply

I am looking for help building a solar data capture device.

I need someone to build a device that measures sunlight level data, stores it on the device and outputs via USB. The device needs to be small (soda can size or smaller), battery powered and water proof.

Question by    |  last reply

Silver wire vs. Platinum wire for Hydrogen Fuel Cells

I understand that most proof-of-concept hydrogen fuel cells on instructables use platinum wire. Can I use silver-coated wire in place of it, or rather, just any wire? Platinum wires aren't exactly readily available here in the Philippines, and I just want a good proof-of-concept hydrogen fuel cell that's cheap to produce. The silver-coated wire I'm referring to appears to be some sort of jewelry wire. I'm also wondering as to why most people would use platinum wire (is there a special property platinum possesses that other metals don't?). If I can't use platinum wire, then what can I use? Something preferably cheap and over-the-counter.

Question by nutsandbolts_64   |  last reply

How would I go about making a basketball that deflates via remote control?

For a project, I'd like to make basketball that deflates when someone pushes a button on a remote. This is really just a proof of concept for a video, so if the mechanism impedes the ability to play, that's okay for now. Does anyone have any ideas on how to tackle this unusual challenge?

Question by AlfredoSG   |  last reply

Hub motorized 4 wheel drive wireless electric skateboard kit  

Landwheel drive is the newest drive system for skateboards that can be mounted under any deck. Just unscrew your rear truck and replace it with the landwheel Drive .    Specification of Landwheel Skateboard Drive:   Model Landwheel Drive( Dual Brushless in-wheel motors) Distance 20km Power 2 X 1100W Max load: 120kg Max Grade 20% Waterproof Water and dust proof (IP65) Frame Material Aluminum alloy + ABS Battery Li-Poly batteries Range 12-15km Weight 3.2kg (Include Battery) Size: 313 x 174 x 41 mm Certificate CE, FCC, RoHs, MSDS, UN38.3     Details of electric skateboard drive : 1. The Motors Two in-wheel motors Power 2* 1100w  Topspeed  35km/h Maximum Grade 20% Water and dust proof (IP65) Freewheeling when you push Exchangeable wheels 2.The Frame Solid magnesium single frame Click-in mechanism for the battery   3. The Battery Pack Range 12-15km Charge 2-4hours Weight 700g        Energy 94.08Wh    Capacity 3200mah Swappable via click-in mechanism Certified for airtravel Water and dust proof (IP54)   4. The Remote One button device Switch between 2 riding modes LED displaying state of charge Rubber coated for better grip Safety wrist strap

Topic by Hollie hua 

Need help small LED project

Hi write here in hope of some help to make a small LED project, What I want: A LED that blinks for 24 hours once a week. Battery driven. Cheap.  Only need 1 LED. must be able to choose day in some way or programe an IC. Even better would be if I could make the thing weather proof. Noob in this area so any kind of help is welcome. Thx.

Topic by twinned   |  last reply

what kind of fabric could i use for headphone foam noise insulation? Answered

still thinking of making custom headphones for fun. would love to make the cushioned pads on headphones but don't know what sort of fabric is could use around the foam. I want something as waterproof/resistant as possible to protect from sweat. really wanted to make square foam inserts and cover them with the fabric for noise reduction. thanks

Question by plasticpopcorn4   |  last reply

Firesleeve(Silicone Coated Fibreglass Sleeve)

Firesleeve(Silicone Coated Fibreglass Sleeve) 1)Silicone rubber coated fiberglass sleeve(sleeving) - Protects hoses, cables and wires. from molten metal splash, high heat hazards and occasional exposure to flame, in steel plants, glass plants, foundries, cutting and welding shops and wherever hoses, cables and wires may be exposed to high heat or occasional flame. Fireproof sleeve also may be used to insulate your race cars plumbing system. 2)Continuous protection to 500F, short term exposure thru 2200F Extremely flexible and conformable through out entire size range at temperatures -65F thru 500F. 3)Impede heat radiation of flame 4)Protect operator from burning by hot pipe 5)Impede heat lost and favor to saving energy 6)Moisture-proof, water-proof, resistance to oil and pollution 7)Color: red and blue mainly. 8)Bore diameter(mm):15,20,25,30,35,40,45,50,55,60,65,70,75,80,90,100,110,120,130;(Sizes from 1/4" I.D. to 6" I.D.) Yancheng Hengsheng Insulation Co.,Ltd Web: Email: Tel :+86-139-61986280 Fax : +86-515-88430696

Question by firesleeve 

What do you recommend as a home DVD player for the next decade ? Answered

Last night our Panasonic DVD QUIT just as we wanted to play Swiss-Family-Robinson for the grand kids. So we had that Yamaha 6 platter player that first lost its VF display and later the player quit too the only reason its still shelved is its the audio drive for speakers installed around the room.. . What is a bullet proof player with easy to use control and HDMI output in your opinion

Question by iceng   |  last reply

How do I bypass a card-reader type security system?

I'm trying to find a way to bypass the security system in my building, a simple card-reader setup. Really more a prank than not.  My boss has been watching my card and logging the times it's accessed, I want to show him that he can't trust the card.  Nothing nefarious, just proof that I can be around and not have to access my card.  If it helps, the security company is Datawatch.

Question by crasymonkey89   |  last reply

How to Build combat suit? What materials are needed for bulletproofing? Cheapest materials that can be used safely? Answered

I have some designs I'm mainly looking for recommendations and references for the materials needed. Also need some advice on kinetic energy replacement for high drops and jumps. Frame material needs to be light weight and strong. Outer armor will be interchangeable. Weapons are still in development more posted later. Also all metals must be nonferrous.

Question by DaVinciStein   |  last reply

copyright laws and answer books?

I want to write answer manuals for textbooks that don't provide the answers in the back in my fields of physical science and math. I want to make my own answers, proof check with others, and probably e-publish it. My question is on the legality of doing this. The copyright aspect pertains to the questions themselves. The answers are all original on my part. Now I suppose it is harder for copyrighted, recently published books but do you think the authors of free albeit copyrighted texts ( are more willing to allow me to do this? How does cramster get away with this?

Question by phillyj   |  last reply

Is it possible to connect a usb cable to a laptop Wlan card and attache it to a dish for a stronger wifi signal?

I want to be able to take the mobile card, water proof it. Attache it to the back of the dish, run an antenna from the front also connected to the the cable with a power hookup. The idea is to raise the wifi signal as well as place the unit anywhere in the house to get a strong db. I was in Puerto Rico a few months ago and because the homes are sometimes built into the side of a hill the signals are weak. This challange should be easy but cheap and can be built with things that are availiable.  Broken computers, wires, discarded sat dish and batteries.

Question by psbcarlos   |  last reply

Can two electric trolling motors with different propellers and maximum RPMs be used effectively on the same boat? Answered

I am building a solar powered electric boat. I want to use more than one motor on the transom. I was wondering if using two motors with different maximum RPM, power, and propeller shapes was possible? Would the propeller of the less powerful motor just add drag or would it add power? Obviously this isn't very specific, but I'm really looking for an explanation or proof of concept. Thanks very much in advance community!

Question by DELETED_craz meanman   |  last reply

The use of soft circuits in robotics

Sheets of touch sensitive material seem perfect for giving robots a "skin" of sorts. This could easily allow for something along the lines of a robot pet that can tell when it is being petted. It would also be useful for robot grippers, to allow the robot to hold on without applying too much force. With a layer of durable plastic between the circuit and the cloth, the robot could be made water resistant. Not really sure where else to take this, but I think touch sensitive, water proof skin (and also whiskers) would go a long way to making better robot dogs and cats, and probably other kinds of robots.

Topic by MDude 

Home made led light with 5w phone charger watt usage?

I have a led bulb which is 5w and I also have a homemade light bulb powered by a phone charger say also 5w. Question is Am I really saving any energy by using a phone charger unit it states it uses 5w? am I using 5w while is plugged 5w or am I using mAX OF 5W OF IT? DOES IT ALSO use 5w when it is only plugged but not powering my led bulbs . bulbs 5v 1 amp, 50 leds. thanks in advance. Also do you know a way to make a water proof glue at home?

Question by celalboz   |  last reply

Step by step settings is needed for Sciphone i68 to use T-Mobile network. Nokia site no longer giving settings.

 I just received an I68 but I can't seem to get instructions for it.  I can call out and that is about it.  My web/T-Zone does not connect, unable to send or receive mms, and no menu or settings buttons to update or add events to my calendar.  I'm able to take a picture but unable to find or send out once taken.  I tried the fool proof instructions only to find that Nokia removed the settings and now instructs you to contact your operator.  Does anyone one have step by step instructions for me?Please help!!!? 

Question by rsjnaylor   |  last reply

Compressing home made biogas

Hi I'm working on a project where we are using an anaerobic digester along with a series of gas scrubbers that yields biogas containing roughly 80% methane (ch4) and 20% oxygen. I know that this proportion of methane is well above the upper explosive limit of methane (about 15% methane by volume) but the presence of that much oxygen makes me nervous.  Am I going to have trouble compressing this gas mixture without blowing a new hole in my head? I am planning on compressing the purified biogas to about 20psi at between 60-80 degrees farenheight and in a respectably blast proof gas container.  please help! (Trying to help our planet!)

Question by Jdouenias   |  last reply

Tiltrotor UAV?

So, a friend and I were looking at something NASA published a while ago. It was a call for a tiltrotor craft that could carry 55 people, could land either in water or on land, and could suck up water for use in firefighting. It was also meant to be a civilian craft. Anyway, we started to get an idea in our heads about designing some sort of tiltrotor rc thing or perhaps a UAV. We're both mechanical engineering majors and have some experience with aerodynamics, programming, electronics systems and rc aircraft. I was wondering if anyone had some good suggestions as to the design of this. One of the things we weren't quite sure about was what we would use for a power supply. Appreciate the help. *Note, if we actually build anything it will only be a small scale proof of concept prototype built from inexpensive parts.

Question by SG1Oniell   |  last reply

isolated buck converter idea Answered

I was wonder as a proof of concept, will this work? this schematic below works by charging a high current capacitor which has a small amount of series inductance to temporarily limit the current, and after charging, the switch (similar to the H bridge configuration) dumps the charge into a storage/smoothing capacitor. By using this method, one can eliminate the cost of transformers in isolated buck converters. A control circuit will control the pulse width into the smoothing capacitor through a negative feedback loop (AKA, as the voltage on the storage cap rises to a target value, the PWM will decrease until the high current capacitor is permanently connected to the DC supply. as the voltage drops, the duty cycle will increase to a 50% maximum.) I am just curious why this might not work, and if it does, does such a system already exist?

Question by -max-   |  last reply

For All the Concrete Enthusiasts at Instructables

Dr Purnell is actively seeking other researchers, engineers, scientists, designers or even sculptors and artists who also have ideas for new uses for cement.I'm not sure if anyone is interested or if someone in the community previously posted this, but I thought I might throw this out to the ingenious and innovative Instructables community. I thought some of you all might be interested.Main Page / Network Link: engineers developing bullet proof vests from cement be a good way for interested Instructables folk to continue contributing on a global scale and to showcase the open-source power of the Instructables community. Plus, it might help you out if you're younger and/or looking for undergrad or graduate level resume boosting aspects for design and/or engineering programs.

Topic by MolecularMaestro   |  last reply

Measure RPM and MPH on motorcylce with Arduino

Hi all, I have an idea for an Arduino based instrument cluster for my cafe racer (1980 xs400). My question is what kind of rotary encoder I should use to measure the rotation from the cables coming from the engine block and front wheel that went to the original cluster (shown in pictures). I want something that won't break at higher RPMs and is more or less water proof. I have an idea of how to code this on the software level as well, but I'm not to experienced with C/C++ so any help there would also be appreciated. The end goal for this part of the cluster is to output the RPM and MPH to respective WS2812B 5050 LED strips, and possibly a small oLED later down the line. If something could be made more clear on this post let me know and I'll try to elaborate. Thanks again

Question by AedanGraves   |  last reply

Any Power Source USB Charger

So here what I have in the works, I'm trying to make a pocket sized gadget that will charge a USB device from anything,  Normal 110v AC, And anything from 4 AA Batteries to a 28v Cordless tool battery,  to a Car Battery, Solar Panel in the middle of Mars, etc, Anything giving off Between 6-35V (Be nice if I could find a 7805 that had a Vin (Max) of 40V, Several manufacturers make 36v cordless tools) . I'll use alligator clips to attach to the battery of choice, and I'll throw in a Diode bridge to make it idiot proof. I plan on having a switch between an AC and DC Circuit. And of course, I'll throw a decent sized heat sink on the regulator. Any Suggestions? I'm not the most electrical savy person out there, so if you foresee any problems, let me know.

Topic by misterpicture 

How can I build a Solar Powered Camera for Car Detection

Hello, I'm looking to build a solar powered camera that detects cars moving past and takes a photo. I've been trialing an off the shelf model that relies on software to detect motion but it does not perform well when the cars are travelling over 15km/h. For this reason I'd like to try and develop a camera that senses the magnetic properties of a car (like traffic lights). I'm open to suggestions but here's how I picture it working: Magnetometer detects car > Micro controller > Camera > Micro controller > 3G/4G antenna > Internet. The system would need to be powered by a battery which is charged by a solar panel. Send me an email and we can chat on how to tackle the project. I work for an environmental consultancy so we can provide you with proof of an internship. Thanks.

Topic by TomF127   |  last reply

Homemade Phone Charger Won't Charge more than 80mA?

I have a homemade linear power supply that can supply 5.1V up to 1.3A. I want to use it to charge a USB device such as a phone. However, the phone is "slow charging" at 80mA. I have tried connecting the data inputs together and then tried setting both data inputs to 2.75V (I have a throw away charger that I measured that voltage from). Both results still only have 80mA going through. How can I make it so the phone accepts a higher current? Is there a specific voltage the data inputs have to be at? I know chargers now "talk" to the phone but I'm just using my power supply as a "dumb charger". Charging the phone is supposed to be a proof that the supply can work. I'm using a Samsung Note 4 and a Note 9 for phones to try charging.

Question by TechBoy54   |  last reply

Spa Controller Modification utilising Microcontroller Remote Station

Hi All, I'm looking at modifying our existing Spa controls with a Touch screen system that combines the functionality of the radio remote for the Spa controller & the remote control panel for the Spa heater. I also want it to be able to run the Sonos software and possibly do lighting control down the track. I would like to leave the existing water proof remote operational if possible but that assumes I can get the new 434MHz module in the microcontroller talking to the existing Rx in the Spa Controller and dont have to replace it. Im interested in any comments particularly as which mini computer to use. Price is a concern of course by function is more important. I havent worked out how to power it yet as there is no easy solution without nearby power points or network ports for PoE. I may perhaps go solar but not sure yet. It may be easier to run a cable for somewhere. Any insights much appreciated...

Topic by BrettB55 

The Ammonia problem...

I am still trying to build a half decent absorption fridge/freezer for the hot summer days down here. Usually anhydrous ammonia and water is used for these old style systems. Problem is that destilling it at home is not the nicest thing, especially in the currently hot weather. So I called up a few refrigeration guys to inquire on the price of some Ammonia if they fill the system for me instead. No matter how I try these guys will only fill certified systems but nothing build in your backyard that is missing the required certifications. Not even for a proof of concept to see if it is working and the gas removed when done with that. Was also informed that making or just having highly concetrated or even anhydrous ammonia would require that I obtain a permit first :( Big question: What are the alternives for R707 or Ammonia in an old style "Icy Ball" system? Small question: Has anyone done it and is willing to share some tips here?

Question by Downunder35m   |  last reply

Is it possible to map data to values in C (for AVR)? Answered

I am trying to make a USB 8x8 pixel LED screen that will display single characters received over serial emulation. I have a proof of concept device but due to my lack of knowledge of C I'm struggling slightly with a specific aspect of the code. To display a character I need to take the 'source' char (such as 0x41) and look it up in the flash memory of the AVR, returning an array of chars (which will be used to render the character). It would be desirable for that information to reside in its own file (a Header perhaps?) - because this would enable multiple interchangeable fonts. This is certainly possible in PIC micro-controller (I made a program utilising data blocks in Assembler a while ago for PIC) and I can't imagine that it's difficult on an Assembler level for AVR either, but I am unsure what I am looking for in the C language. Any help would be appreciated, Thanks, Drew P.S. I'm a Java programmer but new to C and AVR.

Question by andy   |  last reply

Laser detector array?

Hi ladies and gentlemen! I am looking to build a proof of concept, then a prototype on a laser detector array. I need a setup that will pick up a laser beam directed at it from up to 200M away. My idea was to use an array of photovoltaic cells hooked up in pattern. When a laser hit one or more of the cells the current would trip a relay that passed the current to a buzzer or alarm. My concern was that sunlight and ambient refection will cause false signals and trip the alarm. I am sure there is a way to set the system up so that the alarm only went off when there was a voltage spike in a single sensor, or put a variable resistor on it so that only light levels above ambient would set it off. The system will be deployed facing down towards the ground so direct sunlight should never hit the array. I would like to start off with a single photovoltaic cell to prove that the system works and then integrate the others to form the array. Thanks for the help!

Question by KTFlory   |  last reply

Retrofit bug zapper with LED's, Would the high voltage be a problem? Answered

I have a large and good working bug zapper that just had the UV florescent tubes burn out. After pricing out new tubes. which are expensive, it occurred to me to try using UV LED's in place of the tubes. Physically there would be no problem. I can use a 3 inch PVC pipe and wrap the LED string around it. Secure it to the frame and replace the ballast with power supply.  Anyway, I am wondering about the high voltage which will only be a short distance away, perhaps an inch. Would the voltage effect the LED's?  Perhaps an EMF pulse? or are they pretty well isolated and protected? I am using the ones that are coated with water proofing.  Has anyone ever tried using them in a high voltage situation? I have planned on trying this and have already ordered the LED string. I am just trying to foresee potential problems.  I also wonder why I haven't seen any with LED's on the market. Am I actually ahead of the curve on this one?

Question by Vyger   |  last reply

How do you finish your projects? Answered

Whenever you want to finish a prototype, what kind of checklist do you go thru? things like: How do you decide what case design to use, what materials for that same case, how to solder everything up, what makes you decide if you "lock" the Arduino on that project forever by soldering everything around it. If you decide to make it modular, what techniques do yo use. What kind of material do you use to attach everything together: Hot glue? close everything down with screws, nails,  staples (...)? How would you make it water-proof or resistant to the weather (if it was something to be outside for a long time). If you have to use a lot of cable, do you solder everything up with heat shrink tubing? When do you use connectors and what kind of connecters do you use? I would love to see a video tutorial on how to properly finish up a project, and make it look beautiful inside a case.

Question by SgtOneill   |  last reply

How do I connect a stethoscope to a speaker? How can I amplify a heartbeat through a speaker?

Hello, I am a student studying interdisciplinary sculpture. I am working on a project right now where I want the head of a stethoscope to connect to a speaker. I will need two of these, so at least two people can hear their hearts beating together at the same time. My idea is to have a rectangular column made of wood where I will embed the electronics/speakers. The stethoscopes and attached cords will come out of the column, enabling people to pick them up and use them. Is this possible? What kind of microphone can pick up the sounds from a stethoscope? I have already searched the web for solutions and talked to teachers. So far I have not found a fool-proof solution. I have looked at acoustic and electronic/amplified stethoscopes. It seems that the best route will be to take the head of an acoustic stethoscope and embed a microphone into the tubing somehow which will then somehow connect to a speaker/microphone. Any help is greatly appreciated!

Question by i.saralynn   |  last reply

How do you finish you projects? (Arduino)

Whenever you want to finish a prototype, what kind of checklist do you go thru? things like: How do you decide what case design to use, what materials for that same case, how to solder everything up, what makes you decide if you "lock" the Arduino on that project forever by soldering everything around it. If you decide to make it modular, what techniques do you use. What kind of material do you use to attach everything together: Hot glue? close everything down with screws, nails, staples (...)? How would you make it water-proof or make the project resistant to the weather (if it was something to be outside for a long time). If you have to use a lot of cable, is there any good pratice you would suggest? When do you use connectors and what kind of connectors do you use? I would love to see a video tutorial on how to properly finish up a project, and make it look beautiful inside a case. :) Thank you all.

Topic by SgtOneill   |  last reply

Grid Tie and Induction Motors

Yes, I know it's nearly 3am on the east coast... but and idea struck me. So the idea is to feed small amounts of mechanical power into the power grid. Not necessarily run the meter backwards, but supplement power consumption.I've researched grid tie inverters - which are very expensive. For those wondering, a grid tie inverter is feeds mains power back into the grid by syncing phase angle and phase (no dead shorts :) ) and applying slightly higher voltage. They are very efficient and really not within a college student experiment budget :pSo I was thinking... Rather than go from mechanical to DC to AC to grid - go from mechanical to AC to grid VIA an induction motor. As a proof of concept, use a DC motor + battery to turn an induction motor. Plugged into the grid, in theory, should apply current. Oh, but the phase you say? How do you prevent a dead short?"I've thought of this -- before applying mechanical power - have the grid bring the induction motor up to speed. Then try to turn faster (apply a torque) with the DC motor, for example. In theory, the amount of extra power put into the grid will be related to the slip angle of the motor - which will also control the speed of the input (so you can't go over speed by too much).Keep in mind that this whole battery business is just a proof of concept sort of thing - I'm not talking perpetual motion or any hohaa craziness. In the end, the final mechanical input will be around 200 watts. I expect this to be very low efficiency (likely 50%ish), 100W isn't an answer to the energy issues - but it's an experiment. It's also not going to come even close to driving the meter backwards, but it should run (as supplement) my laptop + two to three 13w CFL's :DI think the theory is feasible -- the inspiration comes from flywheel driven UPS systems. An induction motor is driven while mains power is on to keep a flywheel in motion. When the power goes out, the FW drives the motor and feeds to local grid.I'm thinking of using a "low" rpm induction motor.... If I recall, ceiling fans are 16 pole? So that's 60Hz2*2/16=450rpm... Add ceiling fan motor to the list of things to hunt for :) Looking at the one above my head, it looks like it even has a nice bolt pattern for some sort of pulley shenanigans :DCan someone either throw some ice water on me and slap me for being an idiot -- or let me know if I've found a boat to Valhalla.Oh, and my apologies for dancing around the "mechanical input" details.... There's a reason for this, I promise :) In any case, insight and information is appreciated :)

Topic by trebuchet03   |  last reply

Biggest number ever? See for yourself! :P

Alright guys, I got bored, so I decided to make a stupid little thing that I origionally used to do with my calculator in math class. :) Actually, now I have to tell this crazy story.. :P Alright, so I used to do 1+1 a bazillion times in school to see how high i could get my calc to in 1 period of class. Then (since im a MAJOR geek) I got this AMAZING idea. I decided to hook the = button to a microcontroller with a reed relay from radio shack. So I went home, and did just that. I wish I had a picture of it. It was so cool. I let it go and go. :) Anyway, now to the stupid project I made in html/javascript. So, I made this just to "prove" that there is no "biggest number". Now, it doesnt actually find proof so it "could" be wring, but its not. :P Anyway, heres the link: Lol. Thats all I have 2 say. Look at the source code LOL! :P KFSDAGJK  its soooo funny. (to a geek) Anyway, thanks. Later guys! :) p.s., I am at 85,000 on mine.. :)

Topic by sci4me   |  last reply

How can a LED be flashed like a strobe, motion activated and installed outside to act as a security light?

This is about home security.  I have posted another security question on single LEDs in the same category. We have a remote house under construction at the end of a cul-de-sac.  My idea was to create some type of motion-activated single flash strobe or LED burst of light.  This light would be installed at the cul-de-sac and the motion sensor could be further away.  I just want to create this big flash so that any one coming around in the wee hours has to decide if they just had their picture taken and do they want to go further.  The strobe would just flash once like a camera flash, not flashing repetitively. So the final product would have to be weather and water proof.  The house is about 200' from the cul-de-sac but there are a number of empty, underground PVC conduits run from the house electrical panel which could be used to run out 120v or low voltage wiring. I've looked everywhere on the net.  The closest I could find were cameras that are made to take flash photos of animals at night and are motion activated. 

Question by GTinWA   |  last reply