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I wonder if the emi from the pwm could cause some kind of data interference... seems like ram would be an area I would want to be as electrically noise free as possible.

I respectfully disagree. Old Kenwoods, Sansui and Marantz are high quality products that were built to high standards. My old 60 wpc Kenwood KA 7100 still sounds better to my ears than the majority of todays consumer crap. Personally, I don't think many kids today actually have a clue what...

Good god those things look old :) Is that a '79 date code?

I'm wondering what kind of light this is... And why is that most people like to post ambiguous questions? :) Things are so much easier when we know exactly what is trying to be done. I mean, I'm guessing this isn't an ordinary pc mod light, or it would already have a connector on it. Or...

Is that an XT? One thing about the older gear (and I don't consider anything from the Pentium era to be 'old')... I bet it still works. I think much of today's products have half that reliability.

Make sure you get the correct resistors - there are special types for high voltage applications, which may be what you need... I'm sure you have seen this thread. Plain old 1/4 watt carbon resistors just won't cut it if these are used where I think they are, they'll just fry. Be very...

Agent's Mother Of All Supply Links. I've ordered from many of those links at one time or another without issue. I tend to purchase from Digikey if I can't find something cheaper at a surplus place like ALL or BG. I don't know what you mean by 'large' resistor (100 megohms? 100 watts?)...

I guess that depends on perspective and experience... It seems to me that any of these cubes really are just multiple 'planes' of 2D led matrices, where each matrix is driven by addressed high-side / low-side methods. So the driving section is relatively straightforward, albeit laborious to...

A bit of Googling will reveal many sites on LED cubes. I actually purchased leds to build a 10 x 10 x 10 cube, but haven't had the time to sit down and put it all together... I don't think they are complicated so much as they are just time-consuming to assemble the led matrix.

The Arduino is a good suggestion, but it bears mentioning that as a microcontroller platform it is a bit different solution to the problem... Certainly it could be used to perform the task, but you have to create a firmware program for the hardware in addition to any pc software you want to...

I would deem an LED Cube a required accessory for that tabletop ;)

While I found some USB Servo controllers with Linux drivers, they appear less common and more expensive than the PC variety. Perhaps an alternative would be to use std RS232 serial rather than usb, but you would still need to locate a control program or create one yourself.

Unless I am missing something, the only difference here would be filtering of the pwm output to create the (potentially current amplified) analog voltage?

With all due respect, that doesn't mean the voltage follower method suggested above wouldn't work - it's just not going to be efficient. But I'd suggest that is more a compromise towards the technical ability of the OP than the best solution possible. Also, am I to infer that you work for or...

If I understand correctly, he is attempting to use the mobo controlled fan speed output to operate more devices than the 1 originally intended smal fan, and needs a buffer (amp) to provide the additional current. This is unrelated to the mobo fan speed monitoring input signal that has been...

So basically, this has little to do with the the Fanamp at all (because you're not scaling in v out, using a thermostat or the other features), and you just want a plain jane diy buffer-amp based on the mobo's fan speed signal? Mohonri's solution looks to be on the money for that. While...

Designed by Lawrence Welk, the Bubble Machine is an artistic device that creates spherical surface tension bodies that float through the air. This creates a visual representation of electrons passing through a dielectric substrate.

Bob Pease would be proud :)

Blasphemey ! :) I will say that I find a small qty of AVR's on hand can be just about anything you want it to be, eliminating the need to drive to the store to buy discrete ic's... so really I'm saving more in gas ;) Just curious, isn't it more common to use PNP for high-side switching...

While I'm sure you could come up with something like that, have you considered a Lan based remote power utility that uses Shutdown and WOL nettwork messages?

I think that actually might be your best bet... The only other thing that comes to mind would be to use a parallel or serial port pin for the same idea, but that would also require some kind of polling code running in the background that would send a keystroke msg when it detects the switch -...

I've got so lazy with ucontrollers, I don't even bother with asm unless there is some specific need - I paid my dues programming Z80 back in Sinclair days ;) Bascom AVR is an awesome Basic compiler for AVR's with a free demo capable of programming 4kb parts, which is more than enough for...

You could probably do this with a 555 timer circuit driving a relay to switch your load, but really my first choice for anything like this a probably a basic PIC or AVR ucontroller... By the time you calculate and source the couple of resistors and caps you need for the 555 to operate at your...

There are subtle differences between resistance and impedance, primarily in that impedance is ac oriented and will change value depending on frequency... The impedance rating of speakers is an average value over the audio frequency range and will actually be higher or lower at any given time...

I hear that - I recently started ARM7 for that exact reason. They are not much more expensive than many Avr and Pic chips, plus it's nice to have more speed and memory. Several flavors of ARM have onboard usb capability ;-) Be forewarned that ARM is a higher step of complexity in comparison...

Depending on your needs and desires, you may also consider a more conventional ucontroller using a std serial protocol and an inexpensive usb-serial adapter. I have not used Mircochip's usb capable chips, but it seems many of these type of controllers really emulate a serial port type of...

I understand electroshock is coming back into fashion ;)

We don't need no stinkin' metal boxes ;)

Blast from the past :cool: The answer is mentioned in post #8... The resistor rating doesn't reflect the entire circuit load, only what it is actually dissapating itself. At such a low value, most of the current flows right through. It's only a small percentage that is resisted (and...

I'm thinking RFID as well. Chip yourself ;)

The speed that the new chip heated up would make me think that the original damage was not limited to the ic amp chip, so the new chip may have lived a short life anyway. That, with the addition of shorting out the heatsink, would make me look very closely at the power supply before proceeding...

While the theory is 30 years old, the news of actual discovery seems only 3 weeks old... Perhaps I misunderstand.

The possibilites of this are pretty cool.

That really would have been a much better request. It is what you're after, isn't it? ;) And application makes all the difference in the world. There are usually several ways of arriving at a desired result, but not all of them are going to be economical or efficient. Many times when...

Well, I guess that sums things up. Good luck with your electronics career. I have a feeling you're gonna need it. I will also say that a good understanding of how to request help by providing as much information as possible regarding the issue is a useful tool for just about everything in...

I just mention that because I do a lot of prototyping, and it seems fairly rare you need any substantial current on a negative supply rail, unless you're working with amplifiers or something.

What are you trying to do? What needs that much negative current? Perchance you could use your available resources in a different manner? Maybe just hook something up backwards ;)

I got my dev board... this is one neat little chip. I'm just scratching the surface, but already it's cool to be able to drive a 512 x 384 VGA display (1024 x 768 mode) or composite video with just one chip and a couple of resistors. I can see this being potential mod material with some...

I don't care much for the GTA series, but I'll bitch slap a prostitute on my way home just for kicks.

I just ordered the $19.95 dev board to get a hand's on view of things... I'm sure it will be worth it but gawd knows I've blown $20 on more useless things if it's a wash. Looks like the preferred programming interface would be the $25 usb clip thingy, but if you've got a 25 cent max232 in...