|
I think this might be a good place to ask. I'm getting a lot of "intereference" for lack of a better word on the front ports of my computer case. Right now I can hear this noise from my MP3 player syncing, and I cant talk to anyone when I have the receiver for my XBOX controller plugged in. Is there an easy enough fix for this I could do? The receiver doesn't work when plugged into the back so that's out.
|
#
?
Aug 15, 2012 03:31
|
|
|
|
| # ? May 30, 2024 14:20 |
|
|
Fooley posted:I think this might be a good place to ask. I'm getting a lot of "intereference" for lack of a better word on the front ports of my computer case. Right now I can hear this noise from my MP3 player syncing, and I cant talk to anyone when I have the receiver for my XBOX controller plugged in. Is there an easy enough fix for this I could do? The receiver doesn't work when plugged into the back so that's out. I take it you've got a headset plugged in you're hearing this in? It's ground noise, caused by either poor quality wiring or poor ground layout in the case/motherboard, combined with a lot of EMI from the computer parts. Probably all of the above, in my experience. Really there's no easy fix, aside from not using the front ports, the best solution is to get a USB sound card to drive your headset and put it as far away from the computer as possible. Alternately a hi-fi receiver connected via optical will be ideal since there's no ground to fault. If you built it yourself you can check that there's a solid connection for the USB port headers internally, if for example the ground pin on the usb header were loose, that would force ground return current through the audio-ground wire, making your problems much worse. If there's little or no noise on the rear ports, you can get a cheap stereo jack extension lead and run that somewhere away from the case and to your headset.
|
|
#
?
Aug 15, 2012 09:26
|
|
|
CapnBry posted:Has no one responded to this? Your math is somewhat cocked up .... Use a LED calculator like: That is really helpful, thanks. I appreciate it. Funnily enough, 6 Ohm seemed wrong to me and I was going to pick 680 Ohm as a random starting point and the calculator suggested 680 exactly. I guess my subconscious is better than my conscious thoughts. Slanderer posted:
I have a breadboard and a bag of resistors, so I was thinking of trying a range of different resistors and seeing what works best. quote:This is written based on replacing very similar indicator lamps in audio equipment. Maybe it'll help you a little, or give you some ideas. Interesting, thanks. It's an odd fitting: it looks like the bulb is slid into a funnel that directs/diffuses the light to the display. It may be that enough escapes the side of the LED to successfully illuminate the display. It's a sod of a construction: the scanner easily opens up, but the ciruit board is hard wired to a smaller board which is screwed into the front panel. You can't unscrew the smaller board as the main board is in the way - so I have to desolder an earthing braid to release the main board. Then, there is a big metal shield on the reverse of the main board that covers the solder points of the lamp and I don't think I can remove that - so I'll have to attach the bulb from the wrong side. Nothing's ever bloody simple, is it? quote:Lastly, if you want to avoid this hassle, try going to radio shack in person and see if they can order you that part #. It isn't on their website, but their website is utter poo poo, and half of their stuff isn't. They may be able to order it for you. Unfortunately, I am in the UK and Radio Shack closed up many years ago. We don't do clever hobbies anymore, or repair stuff. Buy it, use it, dump it. That's our ethos now.
|
|
#
?
Aug 15, 2012 13:42
|
|
|
Slanderer posted:A load of cool xbox info I apologize, but I think I may have wasted your time a bit. After posting here I found a good xbox modding forum and a bloke on there has answered with such detail that I doubt I'll have any further problems. As far as duplicating the buttons go, its really simple. You just attach wires to the existing switch and run them to one elsewhere. Its nowhere near as complicated as I had first read. People have done custom pads from scratch, using only the xbox circuit pad, theres no real complications to modifying any button as long as you have the soldering skills.  Oh yeah, and all of the buttons use a common ground! So for my LB+A/RB+A toggle switch all I need is a DPDT switch with A on one side and RB/LB on the other, no resistors, relays or diodes needed. He even corrected ALOT of my incorrect knowledge of the standard analogue stick Potentiometers. Apparently my assumption of them having 300 degrees of travel was incorrect, they only have about 90. That means the actual resistance of them is identical to any pot. This is great news for me as I can do away with the complicated gearing system and simply fit a 300 degree pot with the wheel directly attached. I could even go mad and bridge the outer legs of the steering wheel pot with a trim potentiometer, so I could fine-tune the "deadzone" of the wheel when it reachs full lock. The guy who explained this to me (RDC I think was his handle) is an expert imo, the tutorials and FAQ section is full of his work. He's done full wire traces on all the pads AND on the xboxs themselves. He's even prototyping his own xbox controller pad circuitboard so that its easily moddable. Great bloke and he helped me alot.
|
|
#
?
Aug 16, 2012 02:00
|
|
|
Does anyone here have any experience with metal clad or metal core PCBs? I'm looking at trying them out for a RF power amp, but none of my usual fab houses really offer it, let alone in prototype batches.
|
|
#
?
Aug 16, 2012 05:09
|
|
|
ANIME AKBAR posted:Does anyone here have any experience with metal clad or metal core PCBs? I'm looking at trying them out for a RF power amp, but none of my usual fab houses really offer it, let alone in prototype batches. No experience with metal core/Al PCBs, but are you sure you really need that? How much heat are you trying to dissipate, and what's your max rise over ambient? A couple of continuous 1 oz or 2 oz Cu planes will do a pretty good job of moving heat away from components, and pretty much any reasonable board house should be able to do those thicknesses. Most can even go to 3 oz without much trouble. If that doesn't work, I'd really recommend increasing the airflow or heat sinking before moving to a metal core. It will be much easier to deal with a PCB house you know than trying to find someone new, especially for RF applications. Also, are you sure your package won't be the dominating factor in the heat transfer? fake edit: Nat-Semi has a pretty decent app note on thermal design, if you haven't seen it: http://www.ti.com/lit/an/snva419b/snva419b.pdf
|
|
#
?
Aug 16, 2012 08:07
|
|
|
SnoPuppy posted:No experience with metal core/Al PCBs, but are you sure you really need that? How much heat are you trying to dissipate, and what's your max rise over ambient? And at this point I still have no idea what kind of ambient temperatures this thing will need to work at (apparently that information is privileged or some bullshit), but I know it will be in a very confined space and convection may not be an option. Right now I'm just trying to look at all my options, and MCPCB seems to be a worthwhile one.
|
|
#
?
Aug 16, 2012 14:11
|
|
|
I've got an old (late 70s, early 80s) and it has ... a thing in it I don't understand:  That block has C849 printed on it.... ideas? PS: Thanks to this thread I'm now under the impression that I can fix EVERYTHING by replacing bad caps  (worked for my ASUS P5B mainboard and my Syncmaster 226 display)
|
|
#
?
Aug 16, 2012 17:59
|
|
|
Can anyone remind me of the name for the digital encoding system where adjacent states differ by exactly one bit? For example, a two-bit system would have the sequence 00 01 11 10 It's used for motor control systems so that you can tell where you are and which direction the motor is turning by observing which bit was the last to change.
|
|
#
?
Aug 16, 2012 20:23
|
|
|
quadrature. IIRC.
|
|
#
?
Aug 16, 2012 20:32
|
|
|
Gray Code http://en.wikipedia.org/wiki/Gray_code
|
|
#
?
Aug 16, 2012 20:51
|
|
|
That's the one! Thanks a ton, it's been on the tip of my tongue all morning but I just couldn't quite remember the term. Googling for variations of 'binary code' isn't exactly helpful in this case either. And yeah, I think quadrature also applies for simple two-bit cases too. I should have specified that I was looking for the more general Gray code case.
|
|
#
?
Aug 16, 2012 21:39
|
|
|
Quick silly question: Does an analog multiplexer chip ( CD4067BE ) work with digital signals too? edit: It's for an Arduino project. a_pineapple fucked around with this message at 20:28 on Aug 17, 2012 |
|
#
?
Aug 17, 2012 20:25
|
|
|
vas0line posted:Quick silly question: If I understand your question correctly, using that chip to just pass TTL/CMOS level signals at some incredibly slow speed (i.e., not a digital bus that is clocked), then the only thing you have to worry about is the max voltage allowed by the mux; analog bandwidth/etc can be ignored.
|
|
#
?
Aug 17, 2012 20:43
|
|
|
movax posted:If I understand your question correctly, using that chip to just pass TTL/CMOS level signals at some incredibly slow speed (i.e., not a digital bus that is clocked), then the only thing you have to worry about is the max voltage allowed by the mux; analog bandwidth/etc can be ignored. It's like [16 momentary buttons] -> [mux chip] -> [an Arduino input]
|
|
#
?
Aug 17, 2012 20:45
|
|
|
Anybody have experience with the Tektronix 2246 'scope? I'm looking to pick up an old analog scope for projects at home since I won't be able to just use the stuff in the lab at my university soon. I've found that in a few projects having more than two channels is a big plus, and the 100MHz is very nice headroom but not strictly necessary. I looked through the Craigslist and a guy is selling one of these locally for a pretty reasonable price compared to ebay, and he claims to have calibrated it already. I'm going to go check it out tomorrow, but anybody have any advice beforehand? Also, anybody got any recommendations for a variable power supply, preferably with two outputs) or function generator that are easy to get in the US? Preferably fairly cheap, $100-$200 is my preferred max, although if I need to go higher I'll just save up for a while.
|
|
#
?
Aug 19, 2012 04:38
|
|
|
Arcsech posted:Anybody have experience with the Tektronix 2246 'scope?
|
|
#
?
Aug 19, 2012 09:32
|
|
|
Arcsech posted:Also, anybody got any recommendations for a variable power supply, preferably with two outputs) or function generator that are easy to get in the US? Preferably fairly cheap, $100-$200 is my preferred max, although if I need to go higher I'll just save up for a while.
|
|
#
?
Aug 19, 2012 22:12
|
|
|
FSMC posted:I have a Tek 2445A. It's quite good for what it does but it has the limitations of being an analogue scope. Although four channels are nice, four monochrome signals on the small screen just got confusing. I found that I needed fancier triggering, the ability to freeze the frame, etc, so I ended up getting a digital scope. So it really comes down to what you are going to use the scope for. Thanks! It turned out the guy was a guy who got old electronics tech and fixed it as a hobby, then sold it on eBay/CL. I looked through his stuff and found one that he hadn't listed yet, a 2230, which is a dual-function digital-analog scope. Only two channels, but oh well, it's worth it. I also picked up a function generator, a 1MHz Simpson 420 (hurr  ) for a pretty reasonable price off him.taqueso posted:We have a couple supplies from Mastech at work and have been happy with them. http://www.mastechpowersupply.com/ Thanks! I was actually kind of looking at those, but I wasn't sure. I'll probably pick one up once my poor college student wallet recovers from the scope + function generator. Next up on the list after that is a non-poo poo soldering iron, xacto knife set, hot glue gun, and bigger/better component & tool boxes, probably in that order. I already managed to get a Fluke 87V for free, which is rather nice.
|
|
#
?
Aug 20, 2012 00:39
|
|
|
Warthog posted:I've got an old (late 70s, early 80s) and it has ... a thing in it I don't understand: I might be wrong, but it looks like some kind of inductor or transformer. It's hard to tell without having a larger picture. Capacitors are pretty standard, but a lot of companies wind their own coils when it comes to high-wattage stuff. There's a good chance that it's a custom coil, but it's also pretty unlikely to have failed if that's what it is.
|
|
#
?
Aug 22, 2012 08:44
|
|
|
Just getting some opinions. I do some electrical repair work for my job (nothing crazy, mainly terminations and the occasional component replacement on a power supply or whatever. I've always wanted to get into more component-level and signal diagnostic stuff, and I'm trying to get my gear in order. I have a nice soldering station, a bunch of tips, and a hot-air rework station at work. I'd like to get a scope and a bench meter (I'm sick of my DMM running out of batteries). A local guy is selling: Textronix 2213A, with 2 new leads Ideal 61-795 and a Fluke 8840A bench meter (I'm finding out what options is has, mainly the -09 True RMS option) The Ideal is needed for work, I do a lot of HV cable testing, and need a decent digital megohmeter. He wants $100 for the scope, $100 for the bench meter, and $200 for the megger. I'm going to offer him $300 for the bundle, and see what he says. Am I crazy, is this a good deal, etc...
|
|
#
?
Aug 23, 2012 04:04
|
|
|
sharkytm posted:A local guy is selling: I bought a new scope just recently - what I found in my research is that the Tek 2213 is a pretty decent entry-level analog scope. Make sure you know the difference between analog and digital going in - if you want to look at digital communication signals or logic circuits, an analog scope probably isn't what you want. Otherwise, it's probably just fine for whatever you're doing. $100 is a pretty good price for that one, I saw a couple going for about $150. Assuming it's in good condition, with everything working properly, of course. Find a good signal generator to check that it's still calibrated, too if you can. They aren't too hard to calibrate, just open the cover and tweak a few pots, but it's nice if it's at least reasonably close. Fake edit: this episode of the eevblog is a pretty good example of what to look for when you're examining a used analog scope. Don't know anything about the Ideal. I used one of those Fluke bench meters at school my first year and it was really good to me. Looks to be going for about $200 on ebay, so I'd say that's a pretty reasonable price. Fluke stuff in general is pretty drat awesome too.
|
|
#
?
Aug 23, 2012 05:07
|
|
|
Anyone know of a good USB-to-serial chip like the FT230 series that works as a USB CDC device without a driver install?
|
|
#
?
Aug 23, 2012 17:07
|
|
|
Otto Skorzeny posted:Anyone know of a good USB-to-serial chip like the FT230 series that works as a USB CDC device without a driver install? FT23x series won't work for you? I know TI makes a very similar part, they use it on the MSP430 Launchpads to great effect (TUSB3410 I think).
|
|
#
?
Aug 23, 2012 18:11
|
|
|
USBUART component in your PSoC5?
|
|
#
?
Aug 23, 2012 18:39
|
|
|
Dielectric posted:USBUART component in your PSoC5? The USBFS component in the PSoC requires a design-time master clock >=33 MHz which induces ~120 LSBs of bistability in the ADC when we switch to 6 MHz for low power operation. We're going with an external USB-to-serial because the efforts of several Cypress app engineers haven't been able to fix this. Re: movax - At this point we probably will go with an FT230X of some sort(not sure if our board layout guy would prefer the QFN or SSOP package) and eat the fact that end users will have to do a driver install, since other products that can work with the default USB-CDC driver that ships with Windows still require the user to put a .inf file we supply in the right folder, and a driver installer really isn't more complex than that. The other chips I evaluated (Microchip MCP2200, Exar XR21B1411, Freescale USB2SER) all look inferior. PS - have you gotten a chance to read any of Poul Anderson's Flandry books since last I mentioned them? 
Blotto Skorzany fucked around with this message at 20:50 on Aug 23, 2012 |
|
#
?
Aug 23, 2012 20:48
|
|
|
So I finally pulled out my Arduino board that I bought a long time ago to see what the hype was all about. I programmed it and then went to wire it up only to find out that it operates at 5V logic. What the hell? Who uses 5V for logic these days?
|
|
#
?
Aug 23, 2012 23:21
|
|
|
People who use Arduinos, basically.
|
|
#
?
Aug 24, 2012 01:01
|
|
|
Krenzo posted:So I finally pulled out my Arduino board that I bought a long time ago to see what the hype was all about. I programmed it and then went to wire it up only to find out that it operates at 5V logic. What the hell? Who uses 5V for logic these days? If they ran it at 3.3V, they would have to change the hardware (regulators + crystal) and the libraries (because you'd have to lower the clock speed), which apparently takes them years. Not to mention, they are terrified are interfering with precious "backwards compatibility"
|
|
#
?
Aug 24, 2012 01:06
|
|
|
Well, thankfully, I removed the regulator and am able to feed it 3.3v. I was really just looking for a CPLD with a bit more versatility, something with SPI to control 3.3v logic. Any recommendations?
|
|
#
?
Aug 24, 2012 01:43
|
|
|
Krenzo posted:Well, thankfully, I removed the regulator and am able to feed it 3.3v. I was really just looking for a CPLD with a bit more versatility, something with SPI to control 3.3v logic. Any recommendations? The 16MHz crystal can't, or shouldn't, be used at 3.3 Volts (unless I'm misremembering the datasheet).
|
|
#
?
Aug 24, 2012 01:49
|
|
|
Krenzo posted:So I finally pulled out my Arduino board that I bought a long time ago to see what the hype was all about. I programmed it and then went to wire it up only to find out that it operates at 5V logic. What the hell? Who uses 5V for logic these days? USB uses 5V.
|
|
#
?
Aug 24, 2012 02:17
|
|
|
Trabisnikof posted:USB uses 5V. No, USB provides a nominal 5V rail for device power. The logic levels are nowhere close to 5V. Slanderer posted:The 16MHz crystal can't, or shouldn't, be used at 3.3 Volts (unless I'm misremembering the datasheet). psh, any XO can be a VCXO if you change the bias  !It probably won't be a big deal because the the inverter in the MCU will likely behave just fine at 3.3V. SnoPuppy fucked around with this message at 02:56 on Aug 24, 2012 |
|
#
?
Aug 24, 2012 02:46
|
|
|
Trabisnikof posted:USB uses 5V. From Wikipedia: "Transmitted signal levels are 0.0 to 0.3 volts for low and 2.8 to 3.6 volts for high in full-bandwidth and low-bandwidth modes, and −10 to 10 mV for low and 360 to 440 mV for high in hi-bandwidth mode."
|
|
#
?
Aug 24, 2012 02:48
|
|
|
SnoPuppy posted:No, USB provides a nominal 5V rail for device power. But the reason Arduino uses 5V is because USB provides 5V power.
|
|
#
?
Aug 24, 2012 03:06
|
|
|
SnoPuppy posted:psh, any XO can be a VCXO if you change the bias Looking at the datasheet, the safe operating frequency @ 3.3V is ~13.3MHz. The isn't isn't the built in inverter, it's the rest of the logic that isn't guaranteed to respond quickly enough at 3.3V.
|
|
#
?
Aug 24, 2012 03:13
|
|
|
BEHOLD, I AM AN ELECTRONICS GOD For I've fixed my LCD monitor and its blown capacitors and am using it to post right now. Two of the caps were just large enough to cause some fitting issues with the back plate, but I think I will drill some holes in it tomorrow to make it fit right. Lord, this is great. Thanks for the help, thread. [...] I think I might read some of that textbook in the first post, see if I can figure out what a microfarad is.
|
|
#
?
Aug 24, 2012 03:21
|
|
|
Nebakenezzer posted:BEHOLD, I AM AN ELECTRONICS GOD duh, it's 10^-6 amp-seconds per volt.
|
|
#
?
Aug 24, 2012 03:51
|
|
|
Otto Skorzeny posted:The USBFS component in the PSoC requires a design-time master clock >=33 MHz which induces ~120 LSBs of bistability in the ADC when we switch to 6 MHz for low power operation. We're going with an external USB-to-serial because the efforts of several Cypress app engineers haven't been able to fix this. I would like to find a cheaper replacement for the FTDI stuff. But as you say, the offerings from other manufacturers seem pretty sketchy.
|
|
#
?
Aug 24, 2012 13:54
|
|
|
|
| # ? May 30, 2024 14:20 |
|
|
Nebakenezzer posted:For I've fixed my LCD monitor and its blown capacitors and am using it to post right now. Two of the caps were just large enough to cause some fitting issues with the back plate, but I think I will drill some holes in it tomorrow to make it fit right. This is what I've been doing at work for the last year. They bought a slew of dell flatscreen monitors. And they're all reaching that point where their filter caps are crapping out. I've got a big baggie of 1000uf 16v caps for making these things work again. Cheap damned power supplies. :-/
|
|
#
?
Aug 24, 2012 14:49
|
|