Search for Cluster in Topics

Imac cluster help?

I plan on building an Imac cluster with four 10.4 2002 imacs baised off of this instructables,    my questions are... 1) are there any web browsers I can use on a cluster like chrome? 2) is the cluster program Pooch a good one for what I want to do (I just want a powerful computer cluster that can be used for web browsing) if not are there better programs? 3) All my screens are working so I dont need a vga cable to go to a different screen do I? 4) which of the 4 computers would i plug my keyboard and mouse into? 6) what else could I do on an Imac cluster? 7)would xgrid be better to use than pooch? Any help or ideas would be extremely helpful

Question by lucas wilson    |  last reply

How to build a computer cluster?

Does anyone know a good way to connect some computers together to form a computer cluster that I can use as a single computer. My goal is to add on to it to increase the speed/capacity of the unit.

Question by Pettrocity    |  last reply

Is it possible to make a computer with multiple processors, and if so, how? Answered

I am trying to make my own computer out of the parts of ones that have been thrown out.  The computers I find are really old and slow, so I need to figure out a way to group the processors to increase the speed of the computer.  I anticipate to be running Linux on the machine.

Question by 148wmcquiston    |  last reply

Cactus spine clusters pulled out

Hello. I just bought a Torch Cactus from Lowes today and tried to pull the ugly fake flowers off, but when I pulled the hot glue a whole spine cluster came off of it. I'm just wondering if the cactus will heal from this and how damaging this can be to the cactus overall. Can anyone help me?

Topic by MisterHankie    |  last reply

What is a process that can be run on a computer cluster that displays the time taken?

For my science project this year I need a process that can be run on a computer cluster and that displays how long it took to process. The time needs to remain fairly constant yet be accurate enough to display variations in processing power. For example, let’s say that there is a computer with 4 GHz of processing power. if i were to repeat the same process multiple times then the time taken would be something like 2346765.4567865676 seconds the first time and 2346765.4567865681 the second time, so it would only slightly vary each time. if the processing power would change to 3.95 GHz then the time would change to 2346765.45679 so that variations in the processing power would be evident in the time taken. These are just examples and the values have nothing to do with my actual project but i need something to process with these characteristics. Please ask if clarification is needed.

Question by danielemur    |  last reply

A new (and potentially real) way to produce hydrogen from water

A report in Science News today describes the results of an extremely detailed molecular simulation (full non-relativistic quantum mechanics) which shows how small clusters of (less than two dozen!) aluminum atoms can catalyze the dissociation of water into hydrogen with very high efficiency.  The paper has apparently been accepted by Physical Review Letters, but there's nothing up on arXiv :-( Before the alternative-energy fringe starts jumping up and down, the big roadblock to this mechanism is how to fabricate and distribute aluminum atomic clusters (called "superatoms" in the report; sigh...).  Making "nanoscale" (another annoying word...) clusters of atoms usually involves high temperatures and vacuum systems.   Together, those will consume substantially more energy than you recover from making and burning the hydrogen. However, if that roadblock can be overcome, then this does become a viable technology for fuel cells:  fill a tank with water, pour in a pouch (or bucket) of aluminum clusters (magic pixie dust :-), and hydrogen starts bubbling out.  It will be interesting to see how this shakes out Oh, and the simulation makes cool pictures, too!

Topic by kelseymh    |  last reply

Is there a benchmark file in povray 3.5? and if so, How do you use it?

I have been searching for a way to benchmark my openmosix cluster and i came across povray and povmosix. povmosix is a program that splits a scene into parts to be processed and rendered by separate computers. Unfortunately it only supports 3.5. i know how to use the benchmark in 3.6 but not 3.5. any help would be apreciated.

Question by danielemur  

How could i measure the time in linux from when i start a process and the process ends in a program?

I am running a program called povmosix which uses povray and i need to be able to measure the time as acurately as possible from when i start a process to when the process finishes. I Know how to use the time command in terminal but this doesn't use terminal because it is a program. any help would be appreciated.

Question by danielemur    |  last reply

i want to power a 3 raspbery pi zero from ATX power supply can i ?

Hello guys, i hope everyone doing good, I have this question, i want to power up a raspberry pi zero from ATX power supply (standerd power supply for computer) i have search online for answer but, i don't have clear vision, someone told me to power the raspberry from the purple wire (5V 2A) but i want to power more than one pi, so should i go with red wire ? red wire (5v 30amps), will the 30 amps kill my raspberry ? or the pi will just take 1 or 2 amps from the 30amps ? what should i do ? and sorry for my poor english, god bless you all.

Question by MohdT15    |  last reply

I have an array of LED clusters for a big VU meter. How can I distribute power evenly? Answered

Each cluster consists of 6 LED's, and is controlled individualy by an arduino (through a transistor). If I start with normal power, when more LED's light up, they all dim. If I start with extra power, the first few LED clusters blow. I don't want to have a separate power source for each cluster (there are 15)

Question by Stuffses    |  last reply

Hubble Snaps Images of a Nebula Within a Cluster

The Hubble telescope has snapped new images of a Nebula within a cluster."This Hubble image was taken in November 2008 with the Wide Field Planetary Camera 2. The colors in the image represent a range of emissions coming from the clouds of the nebula: red represents nitrogen, green represents hydrogen, and blue represents oxygen."Quick facts :Distance: 10,400 light-yearsExposure Time: 2.1 hoursRelease Date: January 15, 2009Dimensions: This image is roughly 2 arcminutes (6.5 light-years or 2 parsecs) wide.MUCH bigger images and more info can be found here :

Topic by =SMART=    |  last reply

Is it possible to make a Beowulf Custer with Arduino?

Is it possible to make a small cluster computer using Arduinos? It has been done with Pi, but could it be made with breadboard Arduino? I read about I2C and it seems viable. Anyone had tried it yet? Awaiting some reply Trace

Question by Tanmay Das    |  last reply

What is a distibution of linux for a beowulf cluster that can be used with a cpu benchmark?

I have had lots of questions here recently about similar topics but hopefully this will be my last. I am good with computers but am not comfortable with complex programming. I need a distribution of Linux that is used for computer clusters that can have the processing power benchmarked. Is there a distribution of Linux for beowulf clusters where i would only have to install the os, connect the computers with a router and not have to use complex programming? if so, is there one where the total processing power of the cluster can be benchmarked? If so, what benchmarking software would I use? I will not need to actually run any programs on the cluster. I just need to be able to benchmark the processing power.

Question by danielemur    |  last reply

How to use Scalapack as a benchmark?

For a science fair project I am comparing the performance of MPI and PVM on GPU clusters. The biggest problem I have is finding benchmarking software for PVM. Linpack is the most used benchmarking software, and from there I have gone on to find Scalapack, a set of libraries which has the same type of functions as Linpack, but supports both PVM and MPI. From my understanding, Linpack, Specifically HPL , Is a set of functions along with a program which utilizes them for benchmarking. Scalapack, on the other hand, appears to be only the funtions, with no program. Does anyone know how to use Scalapack as a cluster benchmark that measures performance, in flops if possible?

Question by danielemur  


I remember seeing a bot (a group of bots) on TechTV many years ago (had to have been... hell how many of you still even remember that great channel) where all the master would have to do is give the first bot directions, and it would just go near the other one (IR or RF) and it would pass on the message. All he did was give one bot the midi file for the star wars theme... and the bots organized themselfs to play the song with different notes divided out. He could basically tell them any command and they would work as a team to figure it out. I don't remember what it was called... they WERE cluster bots... but I thought he called it something like bee-bots or something... I call them zombie bots, because you "infect" one and it spreads it.... They couldn't be THAT hard or THAT expensive to make, after you have the basics down... Does anyone else know what I am talking about? Has anyone developed something like theses?

Topic by teamcoltra    |  last reply

Looking for a website with diagrams of superclusters and globular clusters of stars.

Anybody know of a website with diagrams (as opposed to photographs) of superclusters and globular clusters? In particular I'm trying to find a map of M68, M30, and M5.

Topic by royalestel    |  last reply

Are there any linux distibutions that can be used for a supercomputer without complex programming?

I am building a supercomputer and i am not sure how to set up the os. I know that i want to use linux, but most sites I've seen have linux using complex programming. Is this the only way to set up a linux os? Edit: Rather than changing the original question i wanted to add on. I have done more research and i have realized that the proper term for what i want to build is not supercomputer but cluster, though supercomputers do fall under the cluster catagory. when i say cluster, i still want it to act as one computer though i am not sure if that is in the definition of a cluster.  so, what i really need is to find a linux os for a computer cluster of 4 or 5 computers. is this possible without complex programming?

Question by danielemur    |  last reply

How feasible to make cluster of red and IR LEDs?

​hey! I'm very interested in putting together a cluster of both red and IR LEDs for skin rejuvenation, and pain relief (I'm disabled and have back and joint pain). The medical devices for sale online are around $250 - $400. Should I pursue this DIY project or bite the bullet and fork over the money? I have NO electrical skills, but this just seems like something that should be doable!! Feedback plz :-)

Topic by depnomore    |  last reply

How do I make a cluster of pulsing L.E.D.s.

I want to make a pulsing red light to insert into a sculpture project. The finished piece will be about 2' x 2'. They all need to pulse at the same time for the same duration, fade in fade out type scenario. I want the lights to be pretty bright, where do I start?

Question by dangitalltoheck    |  last reply

Linpack Benchmarking on PVM with CUDA?

I'm working on a project comparing the performance of PVM and MPI in GPU accelerated clusters. Naturally, I turned to the defacto standard for computer cluster benchmarking, LINPACK. The problem I'm running into is finding a version of LINPACK for PVM. It does exist somewhere because there are performance comparisons  of systems using LINPACK and PVM. Ive already installed SCALAPACK and all of the other libraries required for it to work, but I can't figure out how to use it as a benchmark. Additionally, I need the benchmark to be GPU accelerated. Ive looked into HPL, which is GPU accelerated through CUDA, but there are no versions for PVM. Does anyone know of a version of LINPACK that can be run on PVM and could be modified to be CUDA accelerated?

Question by danielemur    |  last reply

HELP to make a hanging cluster of LEDs. I would like the LEDs in groups and one group at a time fading in and out.

Hi Everyone, I am new to Electronics (well I did the basic electronic circuits in Highschool but that was many moons ago!) and am needing some advice.  I am wanting to set up a hanging cluster of approx 300 LED lights.  Each LED will be hanging off its own individual wiring.  In the cluster there will be certain lights creating groups.  I would like all LEDS to come on at the start and then fade out. Then one group at a time to fade in and fade out. I have attached a VERY BASIC colour-coded drawing to show what I mean by the cluster and the groups. I am wanting to use LEDS that are smaller that 1cm in diameter.  I would like the warm white look instead of the cool blue white and each LEDs need to be quite bright.  I like the look of the Dome LEDS but am open to suggestions!  This set up would need to be battery powder. I have been trying to research how to set it up but am a bit lost.  I am stubborn and driven so my lack of experience will not stand in my way.  Any help, advice or pointing in the right direction would be awesome. Thanks Team!  

Question by ahartitzsch    |  last reply


Why do you do it? Whatever it is you do that brings you here. So many sciences clustered in one group of people from all walks of life...

Topic by Senseless    |  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

Multiple CPUs

Big movie companies have these server type things (rendering clusters?) for processing their 3D and graphics renderings. I found this on makezine as an example of someone who did a linux home version, but there is no description of how it works. I would like to make a windows render cluster but I need some help. There are two reasons I want to do this: 1- I will be able to run my PC uber-fast, and 2- I can create some big time giant renderings of 3d models. I would really appreciate some help. Thanks.

Topic by gimmelotsarobots    |  last reply

Is it feasable for an eighth grader to build a small (4 computer) cluster running linux?

I am going into eighth grade and for my science project i want to build a computer cluster running linux. for my project  i want to test if the time it takes to process something would be cut in half, thirds and fourths when doubling , tripling and quadrupling the number of computers, or slightly less than half, thirds and fourths because of various factors slowing down processing speeds the more computers are added. Is that extremely impractical or is it possible? if so would i use software types such as pvm or mpi? Finally, are there any suggestions as to what program i should process. i need something that will stay constant ( if i did two tests with the same computer the processing time would generally stay the same) but also take long enough that slight time differences would be noticeable (1 computer takes 2 hours, 2 computers take 1 hour and 1 minute, 3 computers would take 41.5 minutes and so on and so forth).

Question by danielemur    |  last reply

How to wire up this LED?

Hello there, I've bought this cluster of red LED's from Maplins and I'm unsure how I should go about making a circuit that lights them up using a 9 volt battery. (I also have a simple switch). The forward voltage of the LED is 2.5v and the forward current is 30mA. According to my calculations I would need to put a 1/2W or greater 220 ohm resistor in the circuit. Is this correct?Also how do I go about wiring the cluster up as they are in fact 6 individual led's. Do I need a resistor for each? My knowledge of electric circuits is limited. Many thanks, Julian

Question by Joachimanderson    |  last reply

robotics : legs and wheels

Hi !Generally, wheeled robots sound limited, and legged robots too much complicated.So, wheels or legs ? Well, seems it's possible to take the best of the two worlds : Look at this robot !

Topic by chooseausername    |  last reply

I have 4 LED clusters, what voltage and amps should I give them? Answered

I've wired them up parallel with 9.6v and 800mA from an old transformer, but they seem really dim! What am I doing wrong?Here are the specs for each cluster.Technical Specification  Specifications (IF=200mA) Maximum luminous intensity:23000mcd Viewing angle:40 Typical forward voltage:9.6V (11.2V) Peak wavelength:660nm Maximum reverse current:100µA @ VR=18V Power dissipation:2.5W max. DC forward current:250mA max. Reverse voltage:5V max. Operating temperature range:-5C to 65C thanks for your help mark.

Question by Warne00    |  last reply

Anti-Land Mine Robot

I have started design and concept design on a robot to mark (via GPS and UV paint) and destroy unexploded ordinance in Cambodia.  I am assembling teams for various aspects of the project (mechanical, electronics/power, practical application, coding and programming, construction, etc).  While many people have offered their experience and knowledge, the more people contributing can only benefit the end product.  This is not a money-maker, it's a life sustainer.  I'm looking for people who are interested in using their skills to better someone else's existence.   Though it is brand new, you can visit the project's blog at   All advice is welcomed.  Project updates will be regular. Thank you for your time, Huck

Topic by huck alexander    |  last reply

Another IKEA server rack!

I just saw this: an industrial-strength server rack built out of a Helmer filing cabinet. This guy was using it to create Linux server cluster for 3D rendering. Pretty awesome.(I made the super-cheap, half-height one out of Corras side tables.)

Topic by nagutron  

1st time robot. Too ambitious?

Hello All, I have recently started an ambitious project. There will certainly be much learning along the way.  But it is too ambitious? The goal is to build a bot that can be controlled remotely, to aid in the detection, marking, and ultimate removal of unexploded ordinance in Cambodia (in this first application).  Though I have never built a robot of any type, I am quickly learning the basics, but would like ultimate beginner advice if anyone had any.  If anyone would like details on the project, PM me.  It's really a lot for a forum post... If there are any Veterans or military buffs out there, I could really use other first hand accounts of experiencing UEO. Through generous donation and aquisition, I have come cross an electric wheelchair, and many parts needed for a former "Battle-Bot".  Battle-bot turns peace-maker.  I love it!  The motors are Bosche, 24V and ~750watts.  Included were DC motor (high amp) speed controls, and 2x 12v 26A sealed lead-acid batteries.  Very very excited to really dig in.  I lack a quality track or model of a good track to use for traction, etc.  Anyone know of any good and sturdy RC tank tracks I could look at for design or actual construction? Though I began to construct my own track out of sheet metal and various materials available (it actually turned out kinda ok), I don't intend on reinventing the wheel, as it were.  3" took me almost 2 hours. Will also be incorporating a ~3'-4' rotating and articulating arm.  Trying to keep its weight to under ~30lbs.  The wheelchair frame is very strong and moddable, Ws thinking of using a lazy susan type bearing, but I'm not sure I could find one rated for that weight for an affordable price.  Any suggestions? Thanks for checking this out.  Again, if you want more details, I'm happy to share my plans.  Just PM me. This is being designed 100% open-source, and 100% documented with a video and written journal in order to be easily duplicated.   Constructive criticism is NOT personal criticism! Huck

Topic by huck alexander    |  last reply

Issues and safety precautions to take with a 50-70 feet 12v bus line?

Hi  i am thinking of building a emergency LED setup with some 1w or 3w LEDs which will be connected to a 12v bus line powered from a deep cycle battery. I will be using a fuse between the battery and the bus line. I am thinking of placing a cluster of LEDs every few feet(7-10 feet). Each LED will be powerd using a mr16 LED driver using power from the bus line and the driver should consume somewhere around 350ma of current. Each LED will be mounted on a heatsink. Max LEDs in a LED cluster will be 3 no.s . Total current used when all the LEDs are on should be around 6 amps max. So, the question is, what kind of safety issues should i look out for and what type of wire i should use for bus line and the lines to leds. Also, should i be using relays for LEDs or will switches be fine? And what precautions should i take  ?

Question by bipl12    |  last reply

LED advice

I'm trying to source some LEDs, preferably from a supplier in the UK I'm going to mount them on a power kite, so they need to be bright as possible, ideally with a wide viewing angle and low forward voltage - to keep the weight of power supply down. Also, I'm considering options of mounting LEDs in clusters or using a small diffuser (like a ping pong ball, but smaller) to achieve a 360deg viewing angle. Any suggested products or ingenious solutions would be welcome

Question by davidhw  

how to make a waterproof switch for a minisub? Answered

Right now, I am in the process of building a small tethered submarine that is only about 1 foot long. There will be an external light module on it. So far I have a cluster of LEDs and a 9v battery holder that are both waterproof, but I do not have a way of turning the lights on and off that is waterproof. Does anyone have any suggestions on how to waterproof a switch or where to buy a waterproof switch?

Question by macgyver603    |  last reply

How can I fix small dent? (Jewelry making) Answered

So I tried making jewelry from a cluster of amethyst. It wasn't after I glue it in then sanding that I notice the small dent. I believe those dent was cause by my mistakes (It's my first time working with metal). I don't want to scrap it and do it from the beginning.... I'll appreciate it if you can help.

Question by Shizen    |  last reply

im trying to hook up 200 LEDs in groups of 3-4 that can individually be turned off, whats the best way to power this?

So im new to calculating power needed for projects so im hoping for some help im trying to hook up 200 LEDs in groups of 3-4 that can individually be turned off, whats the best way to power this? should i run the 3-4 leds in parallel ? and i need to be able to turn clusters of lights off.

Question by iZombiemovies.    |  last reply

How to make Commercial Grade Apple Cider?

I'm not sure if my question was forwarded, so here it is again!  I have a Food Grade 250gal container that is within a medal cage, that keeps the container from over expanding!  What I want to know is how much Sterling Compound do I need per gal.?  I also want to know how much Yeast it takes for a 'start'? Is it possible, to put Whole Cored Apples into the container and let them break down a 'must'  much like Whole Cluster Fermentation in Grape Wine?

Question by Geno Landrum    |  last reply

Spectrum Analyser circuit help

I've decided to task myself with building a large scale spectrum analyser to get me back into electronics as I figure it will use the most common base components (transistors and op-amps) and will jog my memory on what does what. I know there are a few guides around, but they either give the circuit diagram with no explanation of what's going on, or talk about things that I've long since forgotten. I'm trying to piece together how to build this circuit myself rather than follow a suck-eggs-follow-and-learn-nothing style guide, and trying to re-learn what and how each component works. Right now I've figured that I should be looking to split the output signal into different frequencies and then indicating the volume of each frequency separately. So I plan on using low and high pass filters (band pass?) to split the frequencies into manageable chunks. For getting the volume display I want to do it in roughly 3db intervals as this is roughly double the sound intensity (not entirely sure how I'm going to achieve this), then it's a case of somehow triggering the LED when a certain voltage (volume) is achieved. Finally, rather than triggering a single LED, I want it to set off a large cluster of LEDs (as this is going to be a rather large display), so I'll need some way of triggering the cluster. So my questions here are mainly: Am I going the right way about the project as a whole, or am I in totally the wrong direction? Should I be looking at another method to split the frequencies, or is a low pass plus high pass filter good enough for the job? For the actual volume display, how would I discern the ~3db different? Would I need to double the voltage required to trigger the LEDs (as this I believe would be the double intensity that an ~3db increase would incur)? For triggering the LED section of the circuit, should I be looking at op-amps or transistors? Lighting a large cluster of LEDs from what I assume to be a low voltage output, should I be looking at using a transistor as a switch? Finally, can anyone recommend some good online reading material while I try and source my old college paperwork (it's been a fair few years, but I know it's here somewhere...)? Hopefully I've not just reduced you to a shaking wreck with my obvious obliviousness, and thanks in advance to anyone who helps!

Topic by Auraomega    |  last reply

Use brushless DC motor (or stepper motor) as RPM sensor?

Hi all, I'm making an Arduino based digital instrument cluster for my 1980 XS400 motorcycle. all the old tach and speedo instruments are mechanical so I need to convert the spinning cable's rotation to digital RPM. I've tried IR tachs but I can't seem to get them to be accurate enough (the lowest RPM I could get out of them was about 375, which isn't low enough) I'd love to use a more mechanical means of getting the RPM. could I use a 3 phase DC motor to count RPM? if I can, how?

Question by AedanGraves    |  last reply

AUDIOPHILE? I have bad distortion/feedback?

Made a ghetto beats boombox from a old logitech surround sound system i had. And my issue is distortion in the subwoofer mostly and when i touch the wires going from the amp to the sub level knob i get really bad feedback through the sub and it will cut out also. I know the wiring is a cluster fudge and this was just a "going to wire it up to see if it works then protect it all later" kinda job. Do you think non insulated wire could be the culprit? Any input is appreciated. Def a newb when it comes to custom audio. I know car audio but this is def different. And on another note, I was thinking about just getting another amp to simplify it. Any suggestions?

Question by Argmeister    |  last reply

I need an air moisture meter and possibly a thermometer in one.

Good day,I am trying to find a moisture and temperature meter (possibly in one). It will be a used in a beehive. During the winter the bees cluster together to keep warm. Warm air rises up and gets in contact with the cold ceiling. It cools off and releases moisture. The water then starts dripping down and creates a mess of wet bees and mold. Opening the hive during the winter is not recommended till temperatures get back over 40F. Proper ventilation is possible to achieve through the design of the beehive but i would like to know the level of moisture and temperature if i was to just walk next to the beehive. I have seen a few instructibles about moisture meters but they are geared more toward soil moisture. I need it for the air. The system could be powered by a rechargeable battery and a solar panel - i can take care of that myself. Thanks.

Topic by PavelA12    |  last reply

Fading LED Circuit

GOAL- My goal is to light up a small model I have using an LED circuit that will automatically fade in and out. DESCRIPTION - I will be using 19 blue LEDs (3-3.2V fwd voltage, 20mA fwd current) and would like them to fade in and out on their own very slowly. I am thinking that this will be powered using a phone charger or other household transformer since batteries don't seem to be a feasible option for this (too many batteries clustered together and/or too short a life span). I have a transformer on hand that runs 5 volts at up to 850mA, so if that works then perfect, if not then I could try to find another transformer. For the sake of simplicity I could add one more LED to make it an even 20, though I would have to drill another hole in my model. TASK - I need the circuit to make these LEDs do their fading. Simple as that. Fading circuits are easy to find on the internet, but I have been having trouble finding anything to meet my project criteria. Any help with this would be immensely appreciated!

Topic by Andrew Wiggin  

I need some advice with a transistor in a turn signal circuit. Answered

I am working on a turn signal system for a recumbent trike and it isn't working correctly. It's based on your basic 555 timer to provide the flashing. An on-off-on toggle switch will select left or right. I didn't want to be running the 555 timer all the time so I thought I would power it through the switch. D1 and D2 ensure the timer is powered when left or right is selected while only energizing the correct transistor. The visible LEDs will be dash panel indicators and external light clusters will be connected to the jacks. The problem I am having is that both left and right lights flash with the switch in either position. I'm pretty sure that the 555 is actually powering both indicator LEDs on it's own through the bases of Q1 and Q2, instead of just switching them on and letting the current from the switch do the work. I only had generic transistors hanging around and I'm wondering if using MOSFETs would solve this problem? My understanding is that they would not conduct enough Gate to Drain current to power the LEDs.

Question by AnotherBrian    |  last reply

Motorcycle Modification, what kind of data might I want?

Hey all, I'm working on a rather complicated modification on one of my motorcycles, and I think I might be using both a rasberry pi and an arduino to drive it. I intend to include some kind of display to use in selecting mod modes. I don't think I'm going to use all of the processing power of either. Since I believe I'll have a digital display to show information to myself, I am wondering what kinds of data I might want to think about including on the screen when I'm not selecting a different mode. I currently have a fuel gauge and a clock, a digital speedometer and a tachometer on my OEM cluster. I was thinking that maybe Heading and or GPS location might be cool. Maybe outside temperature? Or connecting the system to my phone to transmit text/call information? If I had data, maybe I could do something more complicated, but I only pay for text messaging because it's cheap. If I thought of something cool, I maybe would buy some data too. Any ideas?

Question by disturbed1035    |  last reply

What motors to use?

Hi, I was looking for some advise on how many rocket motors I should use for my rocket. The main fuselage/engine mount weighs 150g, and the payload weighs 50. The main engine will be an Estes D12-3, and I also have some C6-7s to use as boosters. I built it to support up to a cluster of 8 around the outside, but I think if I filled it, it would be too much power and it would break apart or be unrecoverable due to the altitude reached. I can either have 0, 2, 4, or the full 8 boosters. From simulations, I will get about 33m from the D12 on it's own, and roughly an extra 15m from each C6 engine added. It is only a simulation though, so I was hoping someone could make a sensible recommendation on how many to use. One more question, how many engines can I simultaneously ignite with the estes igniter (with the igniters in series). I don't have any spare ignition wire, so I can't really test it. I need to be sure that the igniter can supply enough current to fire all the engines, or it will be unstable.

Question by andy70707  

Adding a Buzzer to the Turn Signal Circuit on Ford Pickup

I have a 1990 Ford F150. The turn indicator lights are extremely small and well below the line of sight to the instrument cluster. More often than I like to admit, I will indicate a lane change or turn not great enough to cancel the switch; and the turn signal will stay on because I forget to cancel it. I don't like to see people like me driving with a turn signal on because it's unsafe. I need to fix this. I've checked parts houses for an indicator replacement switch that makes a louder sound and found none. I'm thinking about adding a 70-80 db buzzer to the circuit such that the buzzer will sound when the turn signal is active. In shopping around for a buzzer, I've found widely varying prices and widely varying ranges of voltage that they will require. I'm looking to keep this very inexpensive in case the idea doesn't work out (besides, I'm cheap!). I found a package of 12 buzzers for $7.00 designed for circuit boards that will give me 85 db sound pressure, but they take a 5VDC feed. The truck circuit is 12VDC. I have no idea how many amps they draw but it can't be much. I have very limited knowledge about electronics but assume that a 12v supply will burn these buzzers out if I don't lower it. I'm thinking that I could find the 'hot-on-indicator-on' wire, splice into it and run a wire through something to reduce the voltage (an old automobile cell phone charger, maybe?) then to the buzzer.Is my idea feasible? Am I using a cannon to shoot a flea? I'd greatly appreciate, and be very grateful for, any and all suggestions and comments.cb

Question by Cueball21  

Flickering LED's like a firefly effect?

I got this message over an e-mail, I cant help the guy and hope that yall can help him for me: "Hey guys, wondering if I could get your help with a project for my daughters school play. The effect I want to do is a led sort of fire fly or even a flicker candle effect with about 100 led's. I would like to possibly have control over the amount of time they are off or at times just keep it on steady as a regular flicker effect. The led's would all hang individually above the set, so any resistors would be at the top where you do not see them. I would like this to be powered by a transformer, not battery and plug it in the wall. So to have about a 100 or more random flickering little led's is the goal and executed in the most logical (and clean) way. I have seen long lengths of copper tape and then solder to that or whatever you think. I know this is just a play, but woud mean a lot to my daughter. I can put it all together with a plan and a good source to get the various elements. soooo the idea is have the led's suspended by the cable hanging down maybe 6' from above where I would have a 1 x 4 grid to hang everything from. The led's would either have random flickers on a slow (hopefully) adjustable sequence. Out of 100 led's you would only want maybe 3, 4, 5 (who knows how many yet) on at one time. So just quick little flashes of pulsed light like the flicker candles do. So you would have little clusters of 2 or 3 leds hanging down and I would use black heat shrink to bind it up and the cable (22 guage?) would be black as well. The other idea may be to just have a constant candle flicker effect to each "drop" and leave it at that. Would be great to know how to do both. any sugestions?

Question by HM-Innovations    |  last reply

universe expanding forever?

I saw this article on the BBC news site: which has some astronomers apparently claiming that they have now worked out the fate of the universe from measurements on distant stars magnified through a galactic cluster. The final quote is: Professor Priyamvada Natarajan of Yale University, a leading cosmologist and co-author of this study, said that the findings finally proved "exactly what the fate of the Universe will be". This seems like a pretty bold claim to me - I was thinking that even if we had a lot of such measurements then we would still only be working out the geometry of space/time in the region of our universe that we are capable of seeing. This is likely to be only a small part of the whole universe due to the galactic horizon imposed by the age of the universe against the speed of light. Also, even assuming that the whole universe of 3D space and time that we live in behaved the way they are saying, this is still only working out what would happen due to the universe's own internal dynamics - there are ideas coming out now about our universe being part of a wider multiverse outside the realm that we experience as normal space and time, so even if the universe did expand into a "cold dead wasteland", then something could possibly infringe upon it from outside space/time and make something different happen at any time in the future. Some of what's going on here is just bad journalism - there's a longer article here: which gives a fuller version of the same quote: "The geometry, the content and the fate of the Universe are all intricately linked," says Natarajan. "If you know two, you can deduce the third. We already have a pretty good knowledge of the Universe's mass-energy content, so if we can get a handle on its geometry then we will be able to work out exactly what the fate of the Universe will be." This is a bit more cautious but there's still this idea that by making measurements like this from just one point in space and time we can work out the fate of the whole universe, which I don't really believe. So I reckon these sort of predictions should be taken with a massive pinch of salt, rather than definite statements of what we know. Which may be obvious, but I wanted to say it and see what anyone else thinks?

Topic by ganglion    |  last reply