Later this year, for an electronics course I´m taking, we´ll be given a ¨black box¨ circuit containing various passive elements - resistors, capacitors, and inductors - and asked to design a pre-emphasis circuit that will negate its effect. I´d like to draw up a plan of attack, so: does anyone have any suggestions for experiments to run on the black box to determine the circuit within´s construction? I´ve got access to a function generator and an oscilloscope, of course.
posted on Sep 3, 2008 - 5 answers

Wiring/music equipment question: I have a fairly cheap 30WVox guitar amplifier with a phone/line out jack on the back. When I plug something into the jack, sounds stops coming from the amp's speaker and starts coming out of whatever I plugged in instead. However, I would like it if the sound would come out of both at the same time. How easy or difficult would it be to rewire the amp so that it works this way? I'm good with a soldering iron, but not too great with circuit analysis.
posted on Aug 30, 2008 - 4 answers

My out-of-warranty Samsung DLP has been plagued with issues for the last 6 weeks. Routine issues, or do I have recourse? [more inside]
posted on Aug 23, 2008 - 2 answers

Have you seen the Staples big red button you can press and you get a loud "That was easy"? A co-worker has one and uses it sometimes. But what about a programmable maybe 4 X 4 or 5 X 5 button grid that you can put sound bites on and play at will? Could potentially make a great office toy, given the right type of office environment, and some tact. Hasn't anyone created something like this? I'd like to buy one. (Everything I search for, like "Sound board", bring up the popular flash-based sound boards.)
posted on Aug 22, 2008 - 7 answers

Should I eat – er, solder – this? I'm building a preamp and I just discovered that I'm low on 0.1μF 50v ceramic disc capacitors. My question is about whether it's worth trying to salvage more from another (already disassembled) piece of equipment. [more inside]
posted on Aug 22, 2008 - 10 answers

Anyone know of any non-Radio-Shack retail outlets for electronic components near Philadelphia? I know there are tons of online outlets, but I'm looking for a brick and mortar supplier, and I need more variety than Radio Shack can offer.
posted on Aug 21, 2008 - 2 answers

A probably-out-of-his-depth n00b asks: Weatherproof, "high" wattage electronics power supply? [more inside]
posted on Aug 21, 2008 - 11 answers

I am an algebra teacher and am interested in demonstrating problems by recording them onto my computer using some type of drawing pad input device (so that I can post the solution to my web page for easy out of class access by my students). I also would like to narrate my 'recordings' What drawing pad should I buy? [more inside]
posted on Aug 11, 2008 - 6 answers

DoesorwhydoesntthisexistFilter: A very simple guitar synth. [more inside]
posted on Aug 10, 2008 - 19 answers

Pinpointing gunshot locations by triangulating sound waves: Would this be technically feasible? Would it be legal? [more inside]
posted on Aug 10, 2008 - 18 answers

1. I'd like to take on a portable-electronics-building project. 2. I have none of the required knowledge. 3. ...? [more inside]
posted on Aug 8, 2008 - 3 answers

can you help me locate a circuit diagram of a gps module on internet? [more inside]
posted on Aug 5, 2008 - 5 answers

Anyone know any Chicago retail locations for jewelry supply and electronic components? [more inside]
posted on Aug 4, 2008 - 3 answers

Where can I buy fiber optic cable in a brick-and-mortar store in NYC? Small quantities only. Thanks.
posted on Aug 1, 2008 - 5 answers

I want to buy a 2-pronged figure-8 cable (IEC 320 type c7) with a Japanese plug to work in Japan with my MacBook power adapter. Where should I look for this in Japan, or even better is there somewhere online where I can buy it and have it shipped to Japan? [more inside]
posted on Jul 30, 2008 - 7 answers

Where to buy electronic scrolling LED message sign ... in person? [more inside]
posted on Jul 22, 2008 - 4 answers

I need a turntable to spin. That's it. [more inside]
posted on Jul 20, 2008 - 3 answers

Where around socal can I meet other aspiring electronic do-it-yourselfers? [backyard imagineering] [more inside]
posted on Jul 19, 2008 - 6 answers

ElectronicsHobbyistFilter: Where can I browse around for and buy small electronic components (microswitches, capacitors, etc.) in New York City? Radio Shack no longer appears to carry this kind of stuff (in New York anyway) [more inside]
posted on Jul 16, 2008 - 10 answers

I bought the POWER TOUR Amp and it's really awesome. However I want to modify it and I don't know much at all about electronics. [more inside]
posted on Jul 5, 2008 - 8 answers

Electronics filter. Game show buzzer+. There are tons of simple game show buzzer layouts on the google. What I can't seem to find is an idiots guide to something that would allow you to take an input more complicated that a simple yes/no. i.e. interrupt + [string]. Any pointers?
posted on Jun 26, 2008 - 3 answers

Help me diagnose repeated failure of my lighting dimmers. [more inside]
posted on Jun 26, 2008 - 20 answers

How can I build my own A/B/A+B speaker selector box? [more inside]
posted on Jun 17, 2008 - 10 answers

How can I learn some basic electronics? [more inside]
posted on Jun 15, 2008 - 17 answers

Know of any good resources "out there" specific to information covering the salvaging, repurposing, and/or cannibalizing of cell phone electronics? [more inside]
posted on Jun 9, 2008 - 4 answers

I'm looking for a site that lists the resale value for used electronics. [more inside]
posted on Jun 9, 2008 - 6 answers

What is the purpose of this random noise my electronics are making? [more inside]
posted on Jun 4, 2008 - 11 answers

Where can I find a 50-300µh adjustable coil? I have searched the obvious sites; ie mouser, google, all electronics. [more inside]
posted on May 31, 2008 - 8 answers

I need a manual for a Panasonic VP-8121B AM-FM Stereo Signal Generator. [more inside]
posted on May 29, 2008 - 2 answers

Why doesn't Moore's Law apply to graphing calculators? [more inside]
posted on May 28, 2008 - 21 answers

Help me build a simple intervalometer! [more inside]
posted on May 27, 2008 - 5 answers

I'm interested in learning how to wire LEDs and program/control them. [more inside]
posted on May 26, 2008 - 10 answers

It's not a feature, it's a bug or why do they impair my equipment when not asked to? [more inside]
posted on May 24, 2008 - 28 answers

I am trying to decide which to (learn) to use, The Arduino or The Make Controller Kit. Which should I choose as a first buy / entry level controller? [more inside]
posted on May 18, 2008 - 8 answers

I am charging at least 20, but up to 30 electronic components. Each will draw 300mA at 5-7VDC. What sort of power supply do I need? [more inside]
posted on May 1, 2008 - 10 answers

Help me figure out what to do with some travel money! Specifically interested in arts / electronics / performance festivals, but any suggestions are welcome. [more inside]
posted on Apr 30, 2008 - 16 answers

(Electronics) Is Static Electricity frying my garage door opener, and can a partial Faraday Cage protect it? [more inside]
posted on Apr 26, 2008 - 3 answers

Is my mp3 player frying my headphones? Is this even possible; if so, how? [more inside]
posted on Apr 24, 2008 - 5 answers

How can I use the speakers in my TV as the "center" speaker on my receiver? [more inside]
posted on Apr 7, 2008 - 11 answers

How do I get rid of visual static/noise when using American electronics with my TV in India? Most notably, with my Nintendo Wii? [more inside]
posted on Apr 4, 2008 - 2 answers

We've got an Onkyo receiver for our new home theater that is running really hot....how can I best place a fan to maximize cooling? [more inside]
posted on Mar 31, 2008 - 5 answers

Why does my cellular phone cause my home stereo speakers to make strange noises? Sometimes it happens when a call is about to come in, but mostly it just happens periodically for seemingly no reason. It sounds like strange beepy static and it happpens much more frequently now that I switched to an iPhone. Is there a way to stop this besides throwing my iPhone across the room?
posted on Mar 29, 2008 - 11 answers

So, on lap top power cables, and USB cables, what is that cylindrical object near the end? Kind of like if the cable was a snake, the snake had gotten hungry and just swallowed a plump, unfortunate hamster. (Or a thirsty, unfortunate snake had swallowed a can of soda.) What is it? What's it called? And what does it do? - Digest electrons?
posted on Mar 26, 2008 - 17 answers

I'm trying to get into building electronics and I need some advice. What would be a good place to start? [more inside]
posted on Mar 23, 2008 - 14 answers

I built this mini guitar amp based on this circuit. But I used a 4 watt speaker rather than the 8 watts specified. What are the consequences of that change? [more inside]
posted on Mar 17, 2008 - 8 answers

What sort of electronic device did this thing come from? More pics here, here and here. It was lying on my bedroom floor, and I have no idea where it came from. What is it, and were did it come from? Any ideas?
posted on Mar 2, 2008 - 10 answers

Help me clear up my understanding of how to ground myself when working on my computer. [more inside]
posted on Feb 28, 2008 - 14 answers

Given my love of building things, should I change my major from Computer Science to Computer Engineering? [more inside]
posted on Feb 22, 2008 - 16 answers

Flat TV's behind two-way mirrors? Good idea or no? [more inside]
posted on Feb 19, 2008 - 10 answers

My phone's power button has shifted internally. Help me figure out how to turn on the phone one last time. I need someone with knowledge of circuit boards and the inner workings of electronics or someone who knows about sidekicks. [more inside]
posted on Feb 17, 2008 - 3 answers