Search results

  1. M

    VFD for front panel

    I'm not positive, because I know there are a wide variety of thermistors available, some with positive temp coeffecients (PTC), or negative (PTC), and they start out at different resistances at room temp as well. If the thermometer is calibratable, and your thermistor has the correct...
  2. M

    VFD for front panel

    It looks good at first glance. I would read it online at first, then decide if you need the added convenience of a paper copy. Here's a good place to buy microcontrollers, programmers, and misc components: Here are the rest of PIC links...
  3. M

    VFD for front panel

    If you want to do it independent of a PC, you will want to us a microcontroller. The two most common hobbyist microcontroller brands are Microchip's PIC microcontrollers, and AVR. I personally use PIC, but AVR is also just fine. Although I've never looked at it, Myke Predko wrote some...
  4. M

    LED strips

    About resistors, you definitely want to use them. A car's voltage is not stable, and if you don't use resistors then current increases exponentially as you go past the rated forward voltage of the LED. It probably won't kill them instantly, but it will definitely shorten their lifespan. You...
  5. M

    Variable resistor for LED mod

    Are you trying to find the LED's or the potentiometer? Ebay has pretty good prices on LED's, in the quantities you'll find there you'll end up paying about as much as you would from an online modding retailer, but you'll have a bunch of LED's left over. You can also get the potentiometer from...
  6. M

    Potentiometers to adjust the PSU output?

    Googling for "ATX pinout" will return plenty of results. In fact, this works for most major pinouts.
  7. M

    Wireless Internet Tweakable?

    Just FYI, this belongs in the Network and Security forum. The electronics forum is more for circuits and wiring things. The gains that you could realize from a software program, if such a thing existed, would be minimal at best. It would probably work by cacheing data, predictive...
  8. M

    Timer circuit

    fat-tony: I'm not exactly sure, I kind of pulled that circuit out of nowhere since I know I've seen similar RC timer circuits but couldn't find any schematics handy. But it seems like your way would indeed make more sense. Or you could use a mosfet instead of an NPN, and then just make sure...
  9. M

    Timer circuit

    It's not all that hard to give up your 555 for a genuine RC timer :) There are 4 resistors, 1 cap, 1 zener, and a transistor. If you buy in any reasonable quantity from a site like digikey or jameco, then it'll cost you about $0.04, $0.10, $0.05 and $0.05 respectively, for a total of about...
  10. M

    pcb making help

    You don't really *need* actual printer transfer paper, although it might be a bit easier. Just use a regular laser printer to print out your design (or a copy machine if you don't have a laser available), use an iron to transfer some toner to the board, touch it up with a sharpie, and dip it in...
  11. M

    Where to learn about electronics/digital circuits - A nice complete series of online books explaining just about everything you need to know - A very good basic intro to electronics if you want a slightly easier start.
  12. M

    Timer circuit

    There is an even easier solution that hasn't been mentioned yet, a simple RC (resistor and capacitor) timer. Incidentally, an RC timer is the basis of the 555, but if all you need to do is turn on an LED after a switch is flipped, you don't really need a 555, unless of course you want the LED...
  13. M

    I Plan On Buying An Electric Screwdriver In A Few Days, Which One Should I Get?

    SMPWorksForME: If you don't have anything useful to say, then it's generally better to keep quiet than to proclaim your ignorance in the open. People ask these kinds of questions so that they can get sound advice from people whose opinions they trust, so that they get the best value for their...
  14. M

    Wireless video link

    VNC is not going to provide you with a very satisfying solution. Even over over a 100mbit wired network, it can be laggy. It requires a decent amount of CPU time on either end, and not all of what is output to the monitor will be transmitted over VNC (at least this is how it was the last time...
  15. M

    Felling stupod about USb ports...

    Most regulators need I think about 2-3v higher on the input than you want on the output. They make low drop out regulators which would be better suited, but even those usually need at least 0.5v of headroom.
  16. M

    Felling stupod about USb ports...

    Plug in a meter while there's no load and measure the voltage. That'll at least tell you if the voltage is too high, though not if it's completely stable.
  17. M

    Favorite places to buy/types of soldering irons/solder etc

    This question has come up numerous times here (in other words use the search). Some people are satisfied with a cheap radio shack iron, others buy a soldering station. Based on previous threads, most people who have soldering stations like the Hakko 936.
  18. M

    Felling stupod about USb ports...

    The 3000ma rating is what it can output. What it actually outputs depends on the resistance of the circuit and the output voltage (in this case 5v). Since the ipod is designed for a 5v power supply, as long as your power supply is capable of supplying enough current, then it will work fine.
  19. M

    where can i get a cool "learn how to solder kit"

    I learned from this kit, which includes a soldering iron, solder, some wire cutters, and the kit itself (a siren). If you don't have any tools or solder it is a pretty good deal, but if you do, then just go through one of the above suggested routes.
  20. M

    soldering station

    I also have a Hakko 936 and am pleased with it.
  21. M

    PIC Microcontroller Proyect Ideas.

    Incidentally, why are you using the f84? The 16f628 seems to have taken the f84's place as the most popular hobbyist chip. It supports more things, and is cheaper. A few interesting uC projects I have seen or can think of include -A visual display with a grid of LED's -Something like this...
  22. M

    low voltage X10 fireplace

    I'd also go with the second option. It won't involve messing with the fireplace itself, and should work fine. The only change I'd make is a physical switch in series with the x10 controlled relay, so that you can turn that switch off, and the relay will not be able to turn the fireplace on.
  23. M

    DIY PSU Modulation Kit: How easy is it?

    I'm not sure "modulating" conveys precisely what they think it does, but it looks easy to do, it has instructions. It won't affect PSU operation unless that kit (or your assmembly) is of poor quality. Your specific PSU will probably be about the same as any other.
  24. M

    Electronics.. - A nice complete series of online books explaining just about everything you need to know - A very good basic intro to electronics.
  25. M

    Question about USB power

    Just don't exceed the current rating of 500ma. Depending on the voltage you might be able to put up to two LED's in series, and as many of these in parallel without going over 500ma. Since most LED's are rated for 20ma, that would be 25 LED's (or sets of two LED's) in parallel.
  26. M

    Get 7V from a molex...

    You do use the red wire in place of a black wire. However, black isn't a "-12v ground" or "-5v ground", it is simply a ground, which means 0 volts. With the swap, instead of yellow to black [12v - 0v = 12v], you do yellow to red [12v - 5v = 7v]. And this "7v trick" as it's sometimes called...
  27. M

    toner transfer pcb etching

    How is the 20psi in the chamber applied? Will it press the paper onto the copper clad board (which is what you want)? The only way I've tried the toner transfer method was with an iron, and I got best results when using a pretty heavy presure. If you want consistently good results though...
  28. M

    24v on an ATX Power Supply?

    There must be a common ground between the fan and the mobo if the fan's signal is to be understood by the mobo. This is accomplished by taking the (-) lead from you wall wart and connecting to a ground wire from your PSU, or even to the metal case.
  29. M

    Best way to light up my current keyboard.

    I use two high power red LED's mounted on top of extra keys from a dead keyboard at the top two corners of my keybaord. They connect to the 5v line from inside the keyboard and use a toggle switch on the side. It works well, it's cheap, and it will travel with your keyboard, unlike any changes...
  30. M

    Looking to buy a Dremel for only one thing...

    If all you're doing is cutting blowholes, you would do better to buy a drill and a set of hole saws (or a hole saw for just your specific size fan). They are easier to use, faster, and give good results. If you already have a drill (which is handy for many things besides modding) then the...
  31. M

    Disconnecting LEDs

    It depends how they are connected. If you're talking about power/hdd case LEDs, just unplug from the mobo. If it's some seperate case lighting, it has to connect to power somewhere, and you can unplug it. Failing that, cut the wires and resolder when you sell it.
  32. M

    Using Solid state relays for motor control

    Ah, it is an H bridge. I though you were using 4 relays total, not for each motor. Your problem is almost definitely that you have the wrong two SSR's, or more than two, conducting at the same time, that way instead of current flowing one direction or the other through the motor, most of it...
  33. M

    Using Solid state relays for motor control

    You might start by telling us how you connected it. I'm not quite sure why you'd want two relays on each motor, you can use one for simple on/off control and four for an h-bridge (forward and reverse), and I can't think of a useful way to use two relays. If you want any of the schematics I...
  34. M

    educate me on NiMH AA batteries, and mah

    With less reputable brands (or nonbranded), they may measure under conditions to give the highest mah possible, even if it doesn't represent typical conditions. Or they may massage the advertised value a bit.
  35. M

    24v on an ATX Power Supply?

    If it's a beast as you say, you definitely shouldn't run it using the -12v line (btw, that rail is used for signals in older tech, I believe serial ports and ISA slots). Inverter? It sounds like you're describing a regular 120vac to 24vdc wall transformer, but inverter refers to a DC to AC...
  36. M

    DIY USB/Charger for PSP

    Diodes are a bad solution, their voltage drop can change significantly with current. I had the "bright" idea of using diodes as a form of regulation in a power supply once, and after spending about 10 minutes assembling it on a breadboard, I realized that it simply doesn't work well. Now...
  37. M

    I didn't know what to search for.

    You can use any ground (black wire), not just the one next to it. In the unlikely event that your power supply has nonstandard wire colors, simply look at an atx pinout to orient yourself, and short pin 14 to any of the ground pins. By the way, this is all in the Case Modding FAQ.
  38. M

    Qestion about power buttons

    You could also theoretically get a non-momentary switch, but instead of flipping it on and leaving it on, you then flip it off. I can't think of a very good reason to do that, but it's an option.
  39. M

    rust/oxidation free metal?

    Would aluminum be strong enough for you? It does readily oxidize, but it doesn't change the look of it or weaken it.
  40. M

    So I want to make my own LED flashlight.... is a forum dedicated to flashlights, so I'm sure they'd be able to respond better than I, but here goes anyway. A) Luxeons are pretty common in higher power LED flashlights, I'm not familiar with the other options though. B) The best way is with a switching...