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  1. Hero999

    Re: I need some help in electronics personal project...

    Start your own thread.
  2. Hero999

    power supply ircuit Help

    A lead acid battery will charge very slowly if charged to 13.8V. If it's charged to 14.5V and reduced to 13.8V when the current drops below a certain level, it will charge much quicker.
  3. Hero999

    hi !!!!!!

    A simple first order low pass filter will do that. Above twice the cut-off frequency, the roll-off will be 6dB/octave.
  4. Hero999

    Fm transmitter

    Why did you ask for a circuit that works, if you were only going to build a different one that doesn't work? I could be many things. Are you powering it from a mains adaptor? The internal capacitor might not be large enough so add a 1000
  5. Hero999

    Fm transmitter

    I should can this response. That circuit has, no RF buffer amplifier, so the frequency will drift if objects are placed near the antenna, no voltage regulator, so the frequency will change as the battery runs down and no pre-emphasis so it will sound like an AM radio.
  6. Hero999

    Fm transmitter

    http://www.silicontronics.com/index.php?action=ezportal;sa=page;p=15
  7. Hero999

    Capacitor help for a newbie

    Posting the schematic would help. Generally 100nF ceramic capacitors are used for decoupling but sometimes 2.2
  8. Hero999

    Electro Magnetic Pulse

    So its on YouTube so it must be true. ::) How about posting a link? It's probably fake.
  9. Hero999

    Re: high voltage meter problem

    The meter will have an impedance of 10M so to divide by 10, all you need to do is connect a 90M high voltage resistor in series with it. This can be made using nine 10M resistors in series, each resistor needs to be rated to 1/10th of voltage being measured.
  10. Hero999

    Inductor for FM Tx

    A super-hetrodyne receiver. You can buy one for a fraction of the cost of making one.
  11. Hero999

    Single PCB Production

    If you just want to one PCB, then it will cost a lot more per unit than if you wanted a large quantity. If the PCB is fairly simple, i.e. no solder resist or through hole plating and just single/double sided, you can make it yourself which is much cheaper than having it custom made for you...
  12. Hero999

    I want to Buy Sony LCD TV Online?

    Laugh out loud, the picture in my previous post has changed, oh well, here's another TV suggestion. Yes, this is weird, so the latest innovation is to have a spam signature and program the bot to post random bollocks.
  13. Hero999

    I want to Buy Sony LCD TV Online?

    http://bluebuddies.com/Smurfs_Musical_Toys.htm
  14. Hero999

    Inductor for FM Tx

    With the values shown the calculated frequency range is 85MHz to 225MHz. In practise it'll be lower, more like 80MHz to 160MHz.
  15. Hero999

    Choosing an Oscilloscope

    I wouldn't recommend a PC 'scope unless it's a really advanced one. PC 'scopes tend to lack features found in a simple analogue 'scope: they normally only have one channel and no external trigger input. Someone else bought this Chinese 'scope and they like it, order code: 85-2792. I've never...
  16. Hero999

    Inductor for FM Tx

    That circuit has, no RF buffer amplifier, so the frequency will drift if objects are placed near the antenna, no voltage regulator, so the frequency will change as the battery runs down and no pre-emphasis so it will sound like an AM radio. I'd recommend using this circuit which has all of the...
  17. Hero999

    hey guys

    Please translate this into English; sorry I don't understand gibberish.
  18. Hero999

    power led drivers circuits?

    Then buy a driver and bingo, you have a totally finished circuit. Yes, the datasheet says it's isolated so there will be a transformer. However, it's an SMPS so it'll have a small ferrite cored high frequency transformer, not a laminated iron 50/60H power line frequency transformer. Buy it...
  19. Hero999

    forum topic missing

    The are lots of threads that dealing with the 30V power supply and yes you're right some are missing. The thread linked on that page is missing. I also made some bugfix threads for various projects here (including the 30V power supply) which have all gone missing. This is looking a bit like...
  20. Hero999

    power led drivers circuits?

    That will work, it certainly has the advantages of being cheap and simple. However it's not regulated and is inefficient as the resistor will wate lots of power.
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