micro electronics

Basic of this post is where e to buy micro size electronics for micro flying drones which are insect size? I asked arduino and raspberry pi, no answer yet.  in this post : https://www.instructables.com/id/3D-Printed-Ornithopter-Micro-UAV-Drone/     there is electromotor which OP claim that was used also by inventor of little flying drone...regarding arduino uno board i am not sure that was really used by inventor, please see pictures and videos on youtube....so if someone knows please post where to buy such micro size electronics. Thank you  

Topic by ruma29   |  last reply


Possible to hack a retro clock into a split-flap display?

I've been wanting to make a split-flap display board for a while and hook it up to display various messages/times for my office, however building one from scratch seems to be very expensive due to the motors and parts involved. Is it possible to take a retro-style flap clock and repurpose it to be one of these displays? I haven't been able to find anyone attempting this before, despite it seeming (to me) like a pretty good way to get around the issue of the expensive step motors and gears involved, considering the relatively cheap cost of retro clocks online. Any ideas or opinions? Sort of new to this whole endeavour but willing to do the legwork in executing on the idea if it is possible.

Question by Flip175   |  last reply



Can you use standard choke inductors as electromagnets?

I am making a project where I need very small electromagnets to attract and hold a small metal flap closed when the circuit is turned on. Flap is about 1cm from the magnet and returns to this position via a spring when the circuit is off. In theory is it possible to use inductors used in electronic circuits (for interference suppression etc.) as an electromagnet? Thanks.

Question by laquermonkey   |  last reply



Noob Q about inverter for an ornithopter

I was looking in the back of my Jameco catalog the other day and they listed a product called "Muscle wire". It's apparently a nickel-titanium alloy that shrinks as it heats up. It occurred to me that I could flap ornithopter wings with it (a really small ornithopter). I was trying to figure out how I could switch voltage from one pair of wires (the flap UP wires) to the other pair of wires (the flap DOWN wires) without a microchip. I came up with something I'm sure wouldn't work involving a couple transistors, a diode and a cap. Today on wikipedia I figured out that what I was doing was something close to an inverter.So here's the question: Anyone know of a simple switching circuit that runs on a/c power and does not have square-wave switching characteristics?I'll keep researching this myself, but sometimes 'tis quicker to ask the big-brained and kind hearted (you know who you are).

Topic by royalestel   |  last reply


Cat chip logger

Could you modify the reader in a chip reading cat flap to log the details of the chips t hat pass through it rather than only let recognized chips open the flap? Chip reading cat flaps exist data logging is possible this I know, how to tie the two together is beyond me. Give me detailed instructions I could do it, but I'm more at home with working out how to wind the detector coil than what to do with it. The reason is this My sister has a problem, she is in danger of becoming a cat lady, or at least over run with strays or other peoples cats. Her current plan other than catching the visitors that are clearly street cats and delivering them to the local shelter, is setting a camera trap aimed at her cat flap and posting the visitor photos on the local area FB page with is this your lost cat under it.  couple of the poor conditioned strays she has managed to get to the shelter have been chipped it is  reasonable to assume that some of the others must be to, and they would be easier to catch possibly if their  owners were trying to do it. Even a simpler system that just connected chipped cat with photo, and there by identified which cats aren't chipped so presumably are true strays not just nominally owned would b of help those could then be targeted for capture and re homing first.

Topic by Stan1y   |  last reply


Hi I would like to make an automatic feeder for my pigs using an electric motor to control the amount of feed.

I was going to use pvc pipe and a electric window winder motor to open and close a flap at the bottom of the pipe. Can anyone help on how to automatically trigger the motor to open and close the flap once or twice a day for about 10 seconds. (open 10 seconds, allows grain out and then closes to stop any more grain coming out again. Any assistance would be appreciated. I dont know much about electronics. Dan

Question by dandro   |  last reply


Sky+ box USB connection.

I've just noticed that our Sky+ box has a standard USB socket under a small flap at the front.Does this mean that I can download programmes off the hard-drive onto other devices?How would I do that?

Topic by Kiteman   |  last reply


How does this rotation control mechanism work? Answered

I've been trying to figure out a good technique to control the motor rotation in a split-flap display. I've found two methods that I want to compare. One is with a NEMA8 stepper motor (I want to try to keep things small and easy to replicate), the other technique is with a method I've only seen in one place, and I'm not exactly sure what's going on. You can see the video here. From what I gather, they have a DC Motor, that controls two discs. The right hand disc acts as your zero reference, and the left references each flap in the split-flap display.  I can faintly see a red light flashing that I think is on the left hand connector, that flashes every time a groove in the wheel spins past. The right hand wheel only has one groove in it, and when it's facing straight down, you'll see the LED turn on. I imagine the LED is turning on to let the programmer know that that sensor is picking up the groove, but I don't think it's the sensor. I also think those grooves are super important to the sensing, but I don't know how. I know how ball mice work, but those require a IR emitter/receiver on each side of the wheel. I can't see that here (though it could be hidden). So my question is, how does this work? Or, if it's a better question, what is the simplest/cheapest way to get precision accuracy (and the ability to zero if things shift out of place) out of a DC motor without programming the stopping points? Any help is greatly appreciated.

Question by StumpChunkman   |  last reply


How can I make a remote control flying butterfly ornithopter which can pick up small objects? Answered

An ornithopter which uses -- flapping wings -- remote control -- able to fly for atleast 3 minutes -- Please includes materials and process. Thankyou

Question by amuchaku   |  last reply


How can I make a cat door using the microchip embedded in the cat?

I know about SureFlap but they don't work with US chips! I can't put on a collar and my cat refuses to go through cat flaps. So I need something that lifts or swings automatically.

Question by anothergalaxy   |  last reply


Help a newbie with an led matrix.

Hello world of the internet. I have an Arduino Uno, an ICM7218DIJI, and a ton of leds. I want to make a matrix. Preferably a 64 led matrix. I pretty much need help with all of it because I really have no experience with programming, arduino, or led drivers. The best way would be to dumb everything down. Lol,

Topic by Flap jack   |  last reply


Can magnets in a cell phone pouch damage the phone? Answered

I had a Samsung flip-phone which I kept in a leather belt pouch with a magnetic flap closure. For the first 18 months, the phone was fine. Then it started rejecting calls when I removed it from the pouch to answer it, not every time, but once in awhile. I assumed that I was accidentally touching the Reject button. This kept happening more and more frequently, even after I started being very careful not to touch any of the controls. Finally, it started rejecting the calls when I lifted the flap of the pouch, without touching the phone at all. That's when I got a new phone. Throughout all of this, it worked just fine for outgoing calls, and sometimes even for incoming calls if the phone was not in the pouch when the call came in. As I said, I have a new phone now, and I still have the pouch but I'm kind of afraid to put the phone in it. Has anyone heard of phones being messed up in this way by magnetic-closure pouches before? All I find on Google is complaints about signal interference on the iPhone.

Question by RavingMadStudios   |  last reply


How to create wings for human flight?

All of us have seen humans fly in those triangle shaped gliders. How about creating wings that will do the job? Understood that it requires more than wind to propel it so flapping power could be harnessed.  I need designs and the physics(i.e How much area of wing is required to lift what mass of body and etc.) Please suggest solutions ASAP! My e-mail id is bharadwaj.adiraju@gmail.com Thank You :D

Question by bharadwaj.adiraju   |  last reply


What's the best design for a water rocket?

There's two parts I'm wondering about: - fin design - recovery system design I'm planning to use angled fins. What angle is best? Does the shape of the fins matter, or can I just make triangles out of cardboard? For the recovery system, which is better: airspeed flap or "nose separates at apogee"? The second one is definitely easier to build, though.

Question by MePerson   |  last reply


What is this ODD item i found in my HOUSE?!!? Answered

I found this odd plastic bottle in my house.  It looks like our dog chewed one end of it. What is REALLY odd is the little military green PILL looking thing that was inside.  the pill thing i examined and found it has a clear-flap on top and a hollow inside.. like something was previously inside of it and is now gone.  This thing LOOKS to me like an RFID chip holder for use by a doctor to insert an RFID chip in someone, and then dispose of the empty holder in this case.  Maybe i am being paranoid, but this was IN MY HOUSE!!! it is a very odd thing to find in my house.  If anyone knows what this is, please let me know.  Thanks.

Question by framistan   |  last reply


UFO sighting at my local air show?

I went to my local air show in Cleveland and I actually saw  a shark like figure floating around in the sky it almost looked like a flying fish but backward. It looked as tho it was actually flapping a tail around to fly. After it was way off in the distance I took some pictures of it that hardly compare to the first ones as tho it actually morphed into a more bird like object I was wondering if any one had any opinions on these bazar photos I and my brother took. I will admit im the type to believe in these objects being from other planets, I have seen Videos on Youtube stolen from nasa that resemble this "Thing"  quite closely.

Question by the_burrito_master   |  last reply


I'm stuck between a rock and a voice coil.

I know I think I've posted a question like this before. I have a new sub, it's a car subwoofer origionaly (200 watt max (not rms)). So far it's running off the internal amplifier that came out of my old/blow sub (it was rated for around 100 watts). And I have it ported out the side. I had to do some work on the dust cap, it was torn and the torn peice was flapping and making a lot of noise, so I put nail polish enamel on it, a few coats and seems to have worked, but now on the odd beat it sounds like one of the wires going to the voice coil are loose or it's rubbing on something because it makes almost a crackle noise. I figure if it was rubbing, it would make that noise on every singe beat, but it doesn't always. Is there a chance some of the enamel dripped down into the thing the voice coil sits in and it's rubbing somehow? Thanks for any ideas guys!

Topic by Punkguyta   |  last reply


Flash Power Supplies

I don't have a lot of money to spend on stuff at the moment. What I do have is flash guns. Four of them in fact, three of which can be fired with triggers. Now I could invest in 16 rechargeable batteries. Or should that be 32 in case I run out? And a crap load of chargers.  And extensions cos we have no spare sockets in our house. But that just doesn't seem right to me.   Heres what I propose : 1) make some dummy batteries from wood with wire running through the middle.   Three of these go in each flash to carry the connections  2) a fourth dummy battery carries wires out of a small notch in the battery flap door 3) said wires are connected in parallel to a large rechargeable battery - I reckon a 6v from an old British motorcycle (fast draining) or from a granny wagon (deep cycle) should do the trick.  4) when I'm done shooting I charge this single battery from the mains charger I have (does 6/12v) I figure 4xAA batteries at 1.5v = a 6v battery, bu extra size should last longer, be more convenient than carrying around dozens of AAs and changing them and if I want to use AAs when our and about I still can   Any reasons tho wouldn't work or I shouldn't do it?

Topic by ohowson   |  last reply


Bouncing PC! How to secure PCI/PCIe cards and keep cables in place?

I have a desktop PC with a lot of components including a large number of PCI/PCIe cards. The problem I have is that the machine is regularly transported long distances by a variety of means, including rail, road and sea. What happens is that the (often quite generous) jars and jolts of the journey cause cables to fall out and cards to rise out of their slots at the unsecured end. Each time I have to open everything up and reseat everything. If the machine arrives somewhere where I'm not, it can't be used until I arrive. I've gotten around the problem of SATA cables falling out by purchasing cables that clip into place rather than just flap about in the usual fashion. What I don't know how to do is secure ribbon cables, audio cables, cards and the like.  Because of various constraints: - I can't use plastic zip ties (there's nowhere to secure them) - I can't use brackets (the cards are half height) - I can't swap out or modify the chassis The only option appears to be glue. Old fashioned sticky stuff. Thing is, I've read an awful lot of things on the web and while this question gets asked a fair amount there is no consensus. Some people say to use a conducting type (which seems plain idiotic, given that if applied to a PCI interface it'll short out), and others say to use a glue gun (which might introduce problems with regard to the heat and chemicals). The only suggestion that made sense was a silicon sealant from Loctite designed specifically for circuit boards - Tempflex - but there's almost no information about it and the word 'Temp' makes me concerned it's just a makeshift solution (no pun intended). It's also really too expensive to buy a tube and only then discover it won't work. Does anyone have any thoughts?

Topic by 10,000 Angry Vegans   |  last reply


Laptop Display Upgrade to Touch?

I wish to upgrade my Laptop Display from Non Touch to Touch. I did a bit of research on the internet, but am unable to find a proper answer. Is it possible? I would love to migrate from half HD non touch display to full HD touch display (even IPS). But here in India, I'm unable to find it in this config for 15.6" size (atleast, not cheaply). I have found one display which has a few things common with my old display. Both have TFT with LED Backlight, same size, aspect ratio, resolution and no of pins. Old Display: 15.6 inch TFT with LED Backlight (Non touch) (16:9). Resolution: 1366 x 768. 40 Pins. Part Number: B156XW04V5 Datasheet: https://www.olimex.com/Products/OLinuXino/A20/A20-LCD15.6/resources/B156XW04V5.pdf Cost: ₹5000 ($75 approx) Proposed New Display: 15.6 inch TFT with LED Backlight (Touch) (16:9). Resolution: 1366 x 768. 40 Pins. Part Number: B156XTT01 Datasheet: http://www.datasheetspdf.com/datasheet/download.php?id=923648 Cost: ₹12500 ($180 approx) Would I need to change LVDS cable as well? Existing LVDS Cable: Part Number: P5LJ0 Datasheet: http://www.s-manuals.com/pdf/motherboard/compal/compal_la-7221p_r1.0_schematics.pdf Here are the answers to some questions you might have: 1. Laptop is Acer Aspire TimelineX 5830TG. 2. My Laptop did not have any variant with 1080p display or touch display. 3. The old display is slightly cracked. Hence I need to change it anyway. 4. The top flap, display mounting brackets and bezel are damaged too. And the laptop is 5 years old and am unable to get the replacement parts. Hence I am planning on building a new housing for the new display, in any case. (Suggestions in this regard are also welcome) So a bit of variation in physical dimensions is not a problem. 5. Motherboard is Intel i5 2410M with Intel 3000 graphics processor. Graphics Card is Nvidia 540M. (I couldn't find supported resolutions on official websites, but according to 3rd Party websites, both should support 1080p) 6. I have some experience with Electronic Disassembly and Assembly. 7. I can do soldering, but I'm not very good at it. Hence, would like to avoid it, if possible.

Question by dcthelord   |  last reply


Options to improve cooling and reduce consumption for portable coolers

I recently had to start learning how to service airconditioners on the fast and that learning got me thinking about my portable coolers.... Some of us like to go camping or on longer fishing trips, so there might be one of those 3-way fridges in use or a better cmpressor model. The one thing they all have in common is that they can only cool down to a difference in ambient temperatures. No matter which way we turn it the cooling produces heat and that needs to get away somehow. The other big thing is the cooling cycling - or the lack of it on a warm day. After some reading and thinking I came up with some ideas that might be applicable to your existing cooler if you are willing to mess around a bit. Let's start with the produced heat, shall we? Down here in Australia most people either have the fridge in their4WD or camper. In a car or small camper trailer there is often the problem of airflow, so the cooler might be doing overtime for no other reason than a lack of airflow. If you check online sites like Amozon and Ebay you quickly find fan systems meant to be installed inside the cooler to get lower temperatures and a quicker cooling of fresh goods. The thing is that the box is quite well insulated and the benefit of the airflow goes only as far as it can reach. And even if the box is quite empty and you would have a benefit of the cold air moving around it won't change the fact that "improved" cooling always comes with more heat in this case. But if we use one of these fan systems to actually improve the airflow on the hot side we not only get better cooling but also a reduce power consumption - something worth considering if you have no backup power generator.... This of course brings us to placement. As I have done the mistake myself you might be tempted to put a 3way cooler onto your seat. Opening it with the back free means the lid always gets stuck on the seat, do it the other way around and you block the airflow. If you do put it on the seat then make sure two things match: 1. The thing is secured properly. 2. The airflow from your aircon is able to reach the hot side of the cooler. Even permanent installations in a camper benefit from a good airflow. Often the fridge or freezer is built into some sort of bench and the airflow behind might be very limited. A simple solution here is to add a vent on top of the bench to allow the hot air to escape. A better one is to use a fan that is powered together with the heating element or compressor and drives the hot air to the outside. How to improve the cold side of the box or fridge? Well, to be honest there is not much that can be done unless you are prepared for some serious work. Depending on compartment size, contents and how full it is a little fan can help to keep the temperatures even but it won't help to get it cooler or reduce the cycling periods for the cooling. The only really working way that I found is to use a "battery" for the storage of the cold. The cooling works by checking the inside temp of the box and if above the set temp the cooling won't stop. This is all well and good while we have a constant supply of power but once we are on batteries it would be great to keep the active time to a minimum. A working solution is to build a container that fits around the cooling element. Smaller types often use an aluminium heatsink, bigger types might come with a compressor and an evaporator. In either case proper sealing is important! Most good models are fully waterproof, meaning even if you would fill them with water they would not leak in other areas than the door. But double check and if in doubt use a bit of silicone to make sure. Ok, but how do we "store" the cold coming from the device? Cold packs ;) These things contain a ready to use mix that holds cold temperatures quite well. Another really good alternative is alcohol or radiator coolant, although the last has limited capabilites in terms of holding capaity for the cold as it is desinged to exchange heat fast rather than to keep it. With a suitable sized and sealed box around the active cooling element we will need longer to actually see any cooling happen (with a warm "battery") but that can be compensated for by good planning or a frozen water bottle. If the cooling element is covered with a box of cooling gel then it has to cool this first before anything happens inside the box. But once it does the pack is already far below the normal temp it would have during normal operation. Remember the inside of the cold pack cools down first before the outside will get cold ;) So once the set temperature is reached the device will shut off. But since the cold pack is far below the set temp it will continue to cool our box until the core is warmer than the set temp. Quick thinkers will now say the benefit is lost as the time required to cool the "battery" down again is much longer than the normal cycle time - and they would be correct. But as we get much colder temps inside the gel box the overall running will still be less compared to normal operation. And since from the second cycle on the gel is only warming up to operating temp of the box it will be much faster than with a warm box. Another benefit might be the ease of cleaning and ice removal. Some peltier driven coolers have big cooling fins or a quite bad design for the heatsink allowing mould to grow where you can't remove it easy. If the box is made from stainless steel and flush with the back wall of the box we won't have that problem anymore. Ok, but how much is good or too much for the size and gel content? You got me there as it is bit tricky. You don't want to loose much usable space for starters and you don't want to wait hours for the gel to cool down if the box was not used. IMHO the size should fit the cooling element with about 20% to spare all around. If stainless steel is not an option than aluminium is the next best choice. Thin sheets can either be be cold formed with a hammer or "brazed" with a good torch and the right rods. Ok, before that route is there anything I should consider or do first? Depends ;) 3-way systems usually use a flame or heating elements to heat an ammoia solution. After years of neglect corrosion can form and reduce the amount of heat transfered into the system and reducing the efficiency this way. It might help to take the heating elements out once a year or so to clean them and the contact areas from any corrosion or dirt build up. With a fixed shedule for this you won't have the problem of never noticing a badly corroded heating element either - and this is the main failure on these systems.... Modifying your camper or making a few mods to your 4WD drawer system is not for the faint of heart and should be done with consideration. The last thing you want to do is rush things to find out it was not necessary. Before cutting holes check if you can't find the room for the fan in a different spot and use ducts to control the airflow - sometimes it is easier to blow air in than to get air out ;) When it comes to creating vents or connections for air to the outside always make sure it is waterproof and insect safe! If you can let the outlet go downwards so water won't run in, for 4WD trailers consider a flap to prevent water from going during a river crossing. Flyscreens will not only prevent insects from coming in but on the inside also prevent dust to go eerywhere - allow to the removal and cleaning! The salts used in these cold packs can be corrosive, so you have to make sure there are no leaks and that there is no steel to come into contact with gel - this includes screw ends hidden in through-holes. If in doubt use a coat of paint but keep it as thin as possible. Even on peltier systems it might be impossible to remove the heatsink without massive surgery on the internals. So before you take it all apart to gain access check if it is far easier to seal around the box opening and possible screw connections using silicone. The cooling battery can be screwed on and sealed with silicone as well as an easy escape route. Although for this to work you need to check if the material of the box allows for a proper bond with the silicone! Some materials just won't allow anything to stick at all, even after sanding them. So do a test first in an area where you would be able to cut the silicone away without causing damage. If you can rip or peel it off the surface you should not try to use a cooling battery screwed to the wall, only use a box that is fully sealed with the cooling element and has a seperate back - one complete unit around the cooling element. I have a 3-way system with a freezer compartment that does the cooling for the fridge too - what can I do? These units either provide good freezing with the fridge temps too low or good fridge cooling with no freezing capabilites - depending on the thermostat used. Our problem is that is next to impossible to add a cooling battery of the normal kind to these systems. The L-shaped freezer box can really only be added with a L-shaped cooling battery from underneath. Only if you don't need any freezing at all you could add a cooling battery to fit into the freezer box shape. In either case the benefit is somehow limited by the way the thermostat is used. If there is no temp control for freezing it should be fine. Warnings... Only peltier driven coolers are free from refrigerants. Every 3-way or compressor system uses refrigerant as evident by more or less piping and heating elements. Never attempt to screw anything into a cooling element containing refrigerant! Even if you think between the channels all will be fine it won't be! The material is just pressed to form the channels and any damage caould mean refrigerant leaking out! Use silicone instead and make sure all surfaces are properly cleaned before applying it, also wait until the silicone is really fully cured before putting any stress on it. As said, these cooling gels can be corrosive, especially if DC voltage is involved. Make sure that everything that is not aluminum or plastic is properly sealed before allowing ongoing contact with cooling gels. Do not attempt any of this if you have to ask yourself what tools you might need or how make a suitable container for the gel. If in doubt check Google on how to work with aluminium or stainless steel if there are not enough Instructables for it. The gel will expand a little bit if it freezes, this no problem in a metal container if you allow for a bit of flex or on the side added strength  - whatever suits you better. Another option is to get a few different cold packs (by the active ingredient) and to do a check in a little container. Freeze it and note whe level cold and warm. Little to no difference means nothing to worry in terms of expansion during freezing.

Topic by Downunder35m