how to increase W of audio output ? Answered

Hello , i have a amp with output ~0.5W . I want to make a simple circuit to get a higher output (1w or higher). Please tell me what part i need and how i do it . Thanks! sorry for my bad English :(

Question by login721   |  last reply

help w/ transistors

Does anyone know a good experiment to teach what transistors do? I have read everything I can find about them and I still don’t understand what they do and how they do it. Can anyone help?

Topic by kendallickes   |  last reply

Gears of War Lancer Assault PISTOL. Semi-Auto, (well not yet)working saw.

I'll be posting a pic soon. By the description, tell me if I should post. Up-Update: The saw is crap! It sucks, bigtime! Up-Up-Update!: My semi-auto system wasn't reliable, so I have to use dutchj's mag, barrel, trigger, and system. I WILL ask permission.

Topic by DrWeird117   |  last reply

semi auto shotgun revolver or shotvolver!

Hi people! I'm working on a new semiauto! It's gonna be my first big knex gun i ever made with no instructions! Finished: Revolving part Needed: Rotating mech (for the revolving part) Trigger mech Body

Question by Jedi_man 

Tom Clancy's H.A.W.X error message: HELP! Answered

When I click the little icon to run the program an error message pops up that reads "This application has failed to start because file D3dx9_39.dll was not found. Reinstalling this application may fix the problem. I installed it again and again and still the message comes. P.S yes it is a legal copy, I bought it for £20!

Question by Lowney   |  last reply

Photography Tip (For W-burg)

Here's a good tip for you aspiring photographers!Check it out.

Topic by Bran   |  last reply

Raspberry Pi Zero W

I received a Raspberry Pi Zero W kit (from Adafruit) over the holidays, but it didn't come with any doco. And I haven't found much by Googling. Does anyone know of information that could help me get started? I haven't worked with any Raspberry Pi product.

Topic by arshag 

Knex 4wd w/ steering

I'm building my own 4wd truck with knex, and I want it to have steering. I found my own weird and not-always-reliable way, but I want to see if there is an easier way to build it, like using joints and axles. I can find 4wd cars and cars with steering, but none with both. Suggestions must be MOTORIZED, and WITHOUT MODIFYING PIECES. Thanks for the help!

Topic by Mr._Rodgers   |  last reply

Shocks w/ electro magnetics

Hello Every one this is my first post, and since I am a full time student, full time para legal and full time parent, I'm just going to throw this idea out there and let others build on it. Its just an idea that I have had for years. Concerning electro magnets and shock absorber for your average car. Let me know your thoughts. My main thought is that the magnets would be working with reverse polarity add in electricity and you have a pretty good repelling force for going over those bad Jersey roads. Let me know your thoughts.

Topic by arkburn   |  last reply

Sound Modification w/Arduino? Answered

Is it possible to distort, amplify, or otherwise modify sound using an Arduino in real-time? I was thinking of making a voice modulator that I connect my microphone to in order to change my voice. Quality isn't an issue, I just wondered if it was possible.

Question by ArduMir   |  last reply

Resistor power rating increase in parallel?

Let's say I need to have a resistor in a circuit rated for 10 Watts. If I had two resistors rated for 5 W, could I wire them in parallel to make the equivalent power rating 10 W? I know my resistance will be different but I'm not sure how the power rating would differ.

Question by ishmal1103   |  last reply

How does the num. of turns & voltage on the primary translate to an ideal voltage on the secondary?

In electronics, one of the things that has been the most confusing to me is the physics behind transformers. I have learned of that stupid formula a while back, where the ratio of turns is proportional to the voltage ratio and inversely proportional to the current, however, I know from reality that it is no where near that straight forward. As far as I can tell, it is a bunch of BS. Anyway, I want to know what the REAL story is, how the AC current going through the transformer is related to the magnetic flux through the core, and how that relates to the output of the secondary. What seems counterintuitive to me is that more windings on the primary should yield to a stronger magnetic field in the core for a given current, which means for magnetic flux (???) which seems like it should yield to more induced current in the secondary. Is the answer related to inductive reactance (more turns = more inductance = more inductive reactance = higher impedance at a given sinusoidal freq. = less current per unit of voltage?) Note: If you have a good physics and calc background and understand it to heart, pls do explain. However, I am currently only nearing the end of calc 2 w/ absolutely no formal education in physics, so I may have some difficulty with wank terms and vocab. (a.k.a. do not try to show off how many terms you know attempting to explain things in the most complicated and technical way possible.) Also, any good tutorials online that go into depth into the topic? ----------------------------------- The reason I want to know these things is that I wasn't to build a good 6A 0-+/-15V dual isolated channel linear power supply with many transformer tabs so I can keep the voltage drop on the pass elements as low as possible at variable output's so huge $$$ heatsinks are not necessary due to lower low power dissipation. (I have mostly figured out the LPS circuitry, but have not found a suitable Xformer online.) I can get the laminated magnetic cores needed relatively cheaply, however if I have to do some custom windings, I want to make sure I do not choose the wrong number of windings for the core. (obviously one turn on the secondary and 5 turns on the primary will pop a breaker @ 60Hz... )

Question by -max-   |  last reply

Need a cheap dual-output, center tapped, 180VA 18V 5A transformer?

I am trying to design a nice dual-rail lab power supply and need a cheap dual-output, center tapped, 180VA 18V 5A transformer. The outputs are as follows: Primary: 120V Secondary 1:  9V-0-9V, @ 5A max. Secondary 2:  9V-0-9V, @ 5A max. ======================OR==================== Primary 120V Secondary 1:  9V, @ 5A max. Secondary 2:  9V, @ 5A max. Secondary 3:  9V, @ 5A max. Secondary 4:  9V, @ 5A max. I prefer a transformer for the linear regulator over a switching preregulator, because a switching preregulator sort of defeats the whole purpose of making a nice, high precision, low-noise lab instrument. However, I also prefer to have more than just 2 separate 18V outputs, since that means when the output is shorted and constant current mode kicks in for either the positive or negative rail, I will have a voltage drop of 18V, at a maximum current of 5A, and thats over 90W of power dissipation!!! I think that I can deal with that if thats the only solution, since I am planning on using a large CPU active heatsink for cooling, but I prefer if I was not pushing a TO-247 device to it's thermal limits. I have found this: It is affordable, but it seems strangely cheaper than a lot of other toroidal Xformers on the market. Also, the 2 primaries are not center tapped. It is 200VA though! I have never heard of that company, and it seems like the description of it is written in chinglish. They act like the fact that they over-engineered and under-specced it is a feature (to me, thats how all ratings should be, that should be normal and standard, not a feature.). I have also found this: It would be perfect, but it is $80!!! Very expensive, Also, I do not think it is a nice toroidal transformer, not that that matters much to be, I just like the professional look of a beefy toroidal transformer inside a power supply. Lastly, I have found this: It seems to be very similar to the first find, and it is from a reputable distributor. At $70 it is still expensive, and I do not want to spend over $100 for a homemade power supply. I would just get a off-the-shelf solution for that! What about the possibility of modifying a MOT transformer? How many VA or watts can I expect from the output without active cooling? I know they are rated from upwards to 1000W, but I also know they cannot sustain that power output for a long time without overheating and requiring lots of active cooling, and from what I remember, I believe the core is really being pushed into saturation during normal operation, leading to LOTS of power loss in the transformer core, but can they output 180VA continuously and effectively? Approximately how many turns of wire would I need to achieve my requirements, and what gauge wire should I use? I am thinking 20AWG but someone who has done that before would know better than me.

Question by -max-   |  last reply

Where might one be able to acquire inexpensive IR laser goggles (<$40)?

I'm planning on getting a 905nm IR laser that's pretty powerful, and I don't want to spend a lot on the goggles (from my searching, they're normally pretty close to $200). Does anyone know where to get some decent ones on the cheap?

Question by The Ideanator   |  last reply

Wanted: Bicycle wheels w/ rims

I need bicycle tire for a fishing rod holder that i would like to sell (like the one below but without the pvc)

Topic by OutdoorManiac   |  last reply

Timed Shocker, or Shocker w/ a Timer

I was wondering if anyone knows how to build a shocker hooked up to a timer? Or at least how to hook up a timer to a shocker? If anyone can show me how to hook a good, strong shocker to an electronic timer, i'd be grateful. I already have a timer and i can post pics of it's insides if anyone wants a look, it's the one i plan to use. I was hoping to rig it up to the world's smallest shocker. Thanks in advance.

Topic by DeletedUser   |  last reply


 i am making a cleanser for someone who cannot use sodium or lye. if i sub baking soda for the Na Oh in my recipe would that be sufficient. i don't want to use the experiment i do on myself. thanx in advance

Question by kirstie   |  last reply

10-15 AMPs w/ potentiometer.

So, as a chemist I thought it would be fun to save some $ by making my own hot plate & magnetic stirrer. I am using Thermoelectric cooling device (TEC) to heat my stirrer, and a small DC motor to stir. Here's the problem - if you've ever taken highschool chemistry you will know that a hot plate with a stirrer has a potentiometer for Temp & Stirring speed - I'd like to do the same! Problem: the TEC takes anywhere from 5-20 amps in operation @ 12 volts DC. Adding a potetiometer to this in parallel is out of the question - I can't fine a potentiometer that can handle greater than 2 watts. ( i may just be looking in the wrong place)... So.. all in all I'm looking for nearly 140-170 watts of power for my heating plate. (The motor will be using much less, almost negligble to the heating plate) So, if I can't put a potentiometer in series for power regulation, how can I get my temperature to vary? If this is going to require a circuit board, I may need some help with a design :)

Topic by GreenD   |  last reply

1/8 w resistor for 12v?

Hi, I've been trying to add a LED light for my glove box, since it didn't come with any. I bought one radio shack led with built-in 1/8w 680ohm resistors to see how it was made. I read the 1/8w resistor wouldn't work and it would burn up? Using something like 1/2w would be better. I tested it with a 9v battery and I didn't feel it getting hotter. Maybe just warm? I got some LEDs off ebay many years ago and I have no idea what their specs are. They are 3mm led bulbs. I decided to make my own by using 5 1/8w 150ohms resistors. 150 ohms are the only resistors I have on hand. With the combined resistance of 750 ohms, how much voltage is going to the LED? Will I be fine with just using 4 150 ohms resistors? Will is be dangerous to use the 1/8w resistors? I don't want a fire. Will having more resistors also help spread out the heat among the resistors? I drive 4 hours a day, so the light will only be on for that duration. Thanks

Question by RoboRay   |  last reply

Joule Thief w/ 555 timer

Hello, I have a question about using a 555 timer with a joule thief. I'm trying to build a circuit for some solar powered bike lights but I have a couple of questions... 1. Am I correct in assuming that it's a bad idea to try to run a TLC555 timer chip from the output of the joule thief? Without a load, it seemed to be pumping out at almost 80 volts. 2. I tried building the circuit so that the two rechargeable 1.2V batteries would power the 555 directly, and then the output would sink and source two transistors alternately, which in turn would switch the LEDs alternately, using the output from the joule thief, which was also powered directly from the battery. That resulted in no LEDs lit and some very hot transistors... Bad idea. The TLC555 chip is supposed to run on a supply voltage of 2-18V, but when I tested it with the 2.4V coming from the batteries, it would source, but not sink... Is there any way to build this circuit so the 555 could blink 2 LEDs alternately while the LEDs are powered by the joule thief? The only alternative I can see that might work would be to power the joule thief from the output of the 555 and just blink all of the LEDs at the same time from the joule thief's output. Any help would be appreciated!

Topic by amklose   |  last reply

router bypass (/w toggle switch)

Hello, it's been a while. This problem requires someone with IT experience, and basic wiring. (the two go hand-in-hand really.) An ethernet cable is made up of 8 color-coded cables. the colors are brown, brown-white, blue, blue-white, orange, orange-white, green, and green-white.(for ease of coloring, I didn't differentiate between the mixed/solid wires) The principle works similar to that of a lag switch. The solid orange cable handles the data flow, and in lag switches it is "cut" by a  simple on/off switch. But here, Instead of the solid orange cable being "cut" by the switch, it simply switches the input. Hence the toggle switch.  **I realise you can do the same thing with port forwarding, but however hard I try, it does not work. Even software made to do it won't let me. Before i go out and by 4 ethernet cables that i don't need, i was wondering if this concept would work. From the modem out, the ethernet cable is spliced into two wires, which had two paths: path 1: directly to the router, out a router port and to the switch (red line picture 2) path 2: directly to the switch. (red line picture 3) from the switch, the cable goes directly into the computer tower. with a simple flick of the switch,  the input to the switch would either go through or bypass the router. although the green and blue current (amps) is split, the amperage is joined again at the switch because of Kirchoff's current (?) law. although the orange is split, it cannot flow through both wires at the same time because one will not have any place to flow. because the internal wires are twisted to reduce interference, I would use the required minimum of 2 feet for any segment. Q1: would this work? Q2: if so, would this effect the router because the power is split.  Q3: if so, would an 8-pole toggle switch be the solution? Q4: would this have any negative effects with the power going moving at different rates (destructive interference) Q5: would an alternate setup be more plausible? (see picture 4) Thanks in advance -Pyro

Topic by ich bin ein pyro   |  last reply

can you kill lice w/ proxcide ?

I just need to know if you can get rid of lice w/ proxcide .

Question by    |  last reply

Bumping old question w. insufficient responses?

I posted a question a year ago and got a few responses, but nobody quite answered in the way that would have been useful.  I did appreciate the replies (and expressed so), but none hit the nail on the head. The thread went dormant, you could say.  Is there a way to bump the thread up in the specific forum?  Thanks.

Topic by Joel_BC   |  last reply

How Bright is a 112 Lm/W LED? Answered

Hello, I am on a mission to find a very very bright led preferably in red. I have seen lots of bulbs with ranging prices but don't understand how bright they are. One led I have seen is the Luxeon Rebel LXM5-PD01 which comes in red and is 112 Lm/W, I understand that it means 112 lumens per watt but how bright actually is that? And what would be its power consumption? Thanks

Question by Boba Jett   |  last reply

Instructables Build Night w/ Sugru @ ENTS

Here at ENTS (Edmonton New Technology Society) we have weekly hacker nights on Tuesday. So last Tuesday we decided to turn our weekly hacker night into Sugru night. We had a modest turn out but it gave those interested a chance to play around with Sugru. We had a few people fixing some items around the space, to modifying some existing items, even some impromptu shoe repair. Someone was working on a toy dog and was going to make the lights blink. Big thanks to James Chaulk for helping out!  Here is a few photos of our majestic space on that night:  

Topic by neosamuri   |  last reply

Sound from computer TO midi w/ speakers?

I picked up guitar again, and found that my MIDI keyboard has a good set of speakers. I have a MIDI to USB cable currently, as well as some 1/4" and 3.5 mm jack cables. The ports on the back of the keyboard are Sustain, Headphones in,  Midi In/Out, and power supply. Computer has USB of course, mic in, and headphone out. This is my last resort, as there are no other good speakers that I can use. I want the sound live if possible, too. I'm totally stumped. Even vague answers will help.

Question by Fenderpony   |  last reply

Need help w/ IR Camera project

Ok, so i am working on building a pair of Infrared night vision goggles, I have a $0 budget, so am making this entirely from recycled materials and material i already own, so please no suggestions requiring me to make a purchase, please :) here is my issue: I already have a camera that i am modifying to view infrared only, and i want to have the LCD screen go further from the camera than its ribbon cable will allow. i have considered cutting the ribbon wire and splicing wires between the two ends, but im afraid that it won't work and then i will have no ribon cable at all, and thus of course no screen. so if anyone has any solutions, that would be great

Topic by DIYLemon   |  last reply

Led color control w rotary switch?

I am working on a project to rewire an old industry hair dryer into a funky floor lamp. It has a cool panel on the back that would fit some kind of a rotary switch.  I would like to use an existing product or products to emit blue light and yellow light from the bell of the dryer. The rotary switch would allow me to ramp it from the blue leds to the yellow leds with some cross over in the middle. my challenge is that, while I understand basic electrical circuits, I know very little when it gets into the more technical circuits and arduino stuff. I want to learn but this isn't the project for it. does anyone know of an easy way to set this up?  My  thought was a set of blue strips, a set of yellow strips and a rotary controller. But, I don't know what to search for online. thanks!

Question by mckeephoto   |  last reply

Rotary switch w/ direction based contacts??

I'm looking for a specific type of switch... I believe that it must exist, but I have never seen it... I need a rotary switch, where each clockwise "click" (partial turn) makes one circuit momentarily, and each counter-clockwise turn makes a different momentary conection... example with two light bulbs ( L1 and L2 ) connected to each direction of travel, respectively: If you rotate the knob one "click" (say 15 degrees) clockwise, L1 flashes for a moment, as the knob is in motion. if you continue clockwise, L1 will flash at each "click". If you rotate the knob one "click" counter-clockwise, L2 flashes for a moment. if you continue counter-clockwise, L2 will flash at each "click". There is no center-point, so any clockwise travel corresponds to L1, and any counter-clockwise travel corresponds to L2. does anyone know where I could get a couple of these??

Topic by gschoppe   |  last reply

DC motors w/o gearbox for a robot? Answered

Hi, I'm building a very small robot that uses (obviously) very small DC motors. There's no space for a gearbox to slow down the speed so I was thinking if is it possible to attach the wheels directly to the motors and then controlling them using PWM. What do you think? Has someone already tried this?

Question by giacky98   |  last reply

Using MP3 Player w/o LCD?

Ah, so my brother somehow manage to break the LCD on his [ Sandisk Sansa m200 series] and was going to trash it. I figured, what the hey, I might as well see what I can do. I opened the case up and lo and behold, the LCD was the only visibly broken component. My question is, is there any way to bypass the LCD and use the player as if it had never had a screen? I'd post pictures, but I got to sleep now. Thanks!

Topic by Bran   |  last reply

How can I identify the power rating (wattage) of my scavenged resistors? Answered

I am currently making a mini guitar amplifier, from this instructable,, and i need a 1kΩ resistor. I have accumulated a few components by de-soldering and scavenging parts from old, and broken electronic devices. When I found out i needed a 1kΩ resistor, I looked up the ring code for that value and scanned over my broken electronic circuit boards to see if i could find a match. Which i did, but i do not know how many watts the resistor is rated at. The resistor in question is no more than 3mm in length. I know that quite a lot of resistors are more like 5mm in length. Can you tell from the physical size what the resistor I have is?(I will include a couple of pictures)

Question by mdog93   |  last reply

How can I repurpose an upright base w/ a broken neck?

If I can repair the neck that would be great, if not, then what? I just cant see throwing this beauty in the garbage. So what can I make w/ it? A table, a shelf? Help!!!!

Question by andijo   |  last reply

50W amp 60W speakers? Answered

Ive got a 50w dual output Bluetooth only amp, I've also got Two 60w speakers would putting the max volume into the speakers damage them if played for a while. The speakers are 4" and slightly distort at max , could be from slight under power , the amp is rated at 8v to 24v and I am using a 19 v 3.16 amp laptop power supply Speakers 8ohm 60w  Amp dual output Bluetooth only 50w x2 Amp power 8v to 24v

Question by bonze77   |  last reply

how to hang kitchen cabinets, w/micromave attached?

I am trying to hang 3 kitchen cabinets one w/a microwave mounted underneith and attached to the middle cabniet above to stove

Question by david576   |  last reply

Anybody w/ a star wars costume idea for a female? Answered

My brother is being commander cody for halloween and I want to follow to suit(cheeky, i know).  Any ideas are much welcomed;).

Question by happi cat #71   |  last reply

Best way to accurately measure capacitance w/ osciloscope?

I am sure there are many ways to measure capacitance w/ an oscilloscope, and one of the annoying things is that some capacitors have different capacitance at different voltages and test frequencies. My original idea was to use the RC time constant and a known resistor, but I think this is probably the least accurate way to do this. Would using a sine wave function generator and figuring out capacitive reactance (and capacitance) be the better method? OR what about measuring resonant frequency of a LC tank circuit? Or some other method I have not mentioned? What's the best?

Question by -max-   |  last reply

12v underwater camera sys w/ monitor problems

I have 12v ir camera w 80' lead to a small handheld monitor (aquaview) switch is bad i need schematic or diagram info to fix, contacted dealer and was told no info or service option thru them other than a new monitor from them at $125 tot. have searched everywhere but cannot find this info anywhere, suggestions?had to "dremel" water proof case to access once in found switch is fine but several pwr/ground/vid wires disconnected at solder terminal no way to determine what/where, i need schematic info or suggestions.

Question by l7lushis   |  last reply

Connect timer w Rechargeable 9v to Solar panel?

I am using a rechargeable 9v battery in my irrigation timers.  I would think it would be easy to hook up a small solar panel to charge the batteries during the day and then I don't have to worry about them failing and me not noticing until my garden goes brown.  Two wires join in a pastic coated cap that hooks to the 9volts.  Can't I just take the cap apart and connect the leads from the little solar panel?

Question by solartimer   |  last reply

Instructables Build Night w/ Bare Conductive @ Noisebridge

Last night 5/22 we held a build night at Noisebridge with Bare Conductive paint. There was a great turn out with about 20-25 people including electronics beginners and experts. Some people worked on LED cards provided in Bare Conductive's Instructables. Others experimented with new projects - adding LEDs to sculptures and making pressure sensors. The big take away from the night is the paint is most conductive when it dries!! Special thanks to M.C. Langer for helping me organize and teach everyone and Mitch Altman for helping to coordinate the event.

Topic by Carleyy   |  last reply

Pro Subscription Cancelled w/out my request!?

I received a message from instructables robot & from paypal stating my request to cancel my pro subscription was received & completed. However, I did NOT make this request!! I don't understand what is going on.

Topic by 3monkiesdesigns   |  last reply