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  1. Hero999

    circuit distortion

    Look at the datasheets of the ICs listed by audioguru. Build an amplifier with a couple of transistors and compare its performance (in terms of distortion) to the op-amp equivalent and see for yourself. Study op-amp theory and negative feedback and you'll see that if an amplifier with a high...
  2. Hero999

    When asking for help: Post a link to the project!

    When you need help with a project on this site, please help us to help you by posting a link to the project. There are hundreds of projects on this site; most people aren't going to bother searching through them to find the one you're talking about, more often than not your post will be...
  3. Hero999

    where is transducer and transmitter in PCB Board in ultrasonic radar project

    Help us to help you by posting a link to the project you need help with.
  4. Hero999

    wireless LCD projector

    Please speak English, sorry we don't understand nonsense.
  5. Hero999

    novice

    Look at the datasheet or the bulb for a marking. Apart form that there is no other way to accurately determine the operating voltage for a bulb other than to do an experiment: connect the bulb to a a variable voltage source and increase the voltage until the light produced by the bulb, is the...
  6. Hero999

    AM Reciever (Reply please! as soon as possible)

    Please don't create duplicate threads and keep questions regarding the same project to one thread. I've merged the ferrite antenna question with this thread and deleted the duplicates. Moderator
  7. Hero999

    ir remote control switch board for light,fan etc

    http://www.amazon.com/Koolatron-IR-Remote-Switch-Socket/dp/B0006II7D8 http://www.tradekey.com/ks-remote-control-socket/
  8. Hero999

    There is a trojan pc virus here today.

    It still seems like there's some suspicious code on this site. Maybe the trojan has damaged some scripts so they crash IE and give errors in other browsers? Clicking on the reload button invariably clears the error and it loads properly. I haven't tried the home page yet. I can't get...
  9. Hero999

    power supply protection for car projects

    I thought the gate was driven from a PIC connected to the regulated 5V supply.? Please post a schematic, there's no way I can help you unless you tell me the full story. Yes the gate is the most sensitive part of the MOSFET and it's also highly likely that the TL084 will be killed by the high...
  10. Hero999

    power supply protection for car projects

    Do you have a diode in reverse parallel with the coil? MOSFETs can be pretty tough, most can happily breakdown and absorb a small amount of energy. without being destroyed. The MOSFET is rated for over 8 times the supply voltage so it should be fine as long as you have the free-wheeling diode...
  11. Hero999

    microwave crucible

    I don't know much about this but I imagine that if the crucible were made of a material with the right electrical impedance it could be done. If the material that's too good an insulator won't work because it won't absorb any energy and it'll just pass straight through, if it's too good a...
  12. Hero999

    There is a trojan pc virus here today.

    Got to love the joys of Windows and Internet Explorer. ;D Do you have all the updates installed and are you using Internet Explorer 8? I agree, next time you might not be so lucky.. I'm still getting the same error: this time I'm using Firefox 3.5.5 on Fedora Core 11 Linux.
  13. Hero999

    Looking for temperature sensor with +/- 0.5 degree accuracy at 25 degrees.

    You don't need a current source: use the power supply as the A/D reference and connect the the thermistor as part of a potential divider. Self heating won't be much of a problem as long as you keep the power dissipation low. I doubt you'll find an IC, high accuracy, low voltage and low cost are...
  14. Hero999

    There is a trojan pc virus here today.

    I've installed no script. https://addons.mozilla.org/en-US/firefox/addon/722 This extension blocks all scripts on all sites except the ones you white list which will prevent any malware from being installed, even if your antivirus program doesn't detect it and there's an exploit in Firefox...
  15. Hero999

    There is a trojan pc virus here today.

    This probably has something to do with the error I've been receiving occasionally, nothing bad happens, the site just stops loading. http://www.electronics-lab.com/forum/index.php?topic=19340.0 I don't use Internet Explorer because I don't trust it. I think I'll disable scripting for this...
  16. Hero999

    power supply protection for car projects

    Is the 3A load the field coil of the dynamo? You shouldn't need any surge protection - it's just a coil, adding an inductor would just increase its inductance and give you no benefit. The semiconductor regulator, is the only component that will require any protection.
  17. Hero999

    Project Assistance and help

    Follow the links below my previous post, pay most attention to the second one and you should know enough to do it. If there's anything you don't understand, don't hesitate to ask.
  18. Hero999

    Content Encoding Error

    I get the following error when downloading image attachments: Content Encoding Error The page you are trying to view cannot be shown because it uses an invalid or unsupported form of compression. I am using Firefox 3.5.4.
  19. Hero999

    Project Assistance and help

    What level are you studying? This is pretty simple: use a comparator such as the LM393 and a temperature IC or thermistor. http://www.google.co.uk/search?q=comparator&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-GB:official&client=firefox-a...
  20. Hero999

    power supply protection for car projects

    What do you want the inductor for? To connect to the 3A load? I don't see what adding an inductor to the low current regulator would achieve. The resistor just limits the surge current through the zener to a safe level, it just needs to be low enough to prevent the voltage loss from being too...
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