Jump to content
Electronics-Lab.com Community

Hero999

Members
  • Posts

    2,433
  • Joined

  • Last visited

  • Days Won

    1

Posts posted by Hero999

  1. Here are a few products which should do what you want.
    http://www.grundyagricultural.com/products/energisers/hotline_p80s_helios_solar_electric_fence_energiser_-_0.8j?utm_source=google&utm_medium=merchant&utm_campaign=merchant
    http://www.google.co.uk/products/catalog?q=solar+electric+fence&hl=en&client=opera&hs=wbH&rls=en&channel=suggest&prmd=imvns&bav=on.2,or.r_gc.r_pw.&biw=1920&bih=927&um=1&ie=UTF-8&tbm=shop&cid=10988486057481285151&sa=X&ei=AsNaUJZEws7RBeuPgaAE&ved=0CG8Q8wIwAg
    http://www.agrisellex.co.uk/electric-fence-energisers/solar-fence-energisers/farmer-1000s.html


  2. Good Day!
    I assembled the original schematic.My problem is that the rectifier out turns to be more than 24V, around50V (unusual because the secondary output of transformer I had is 24V

    Why is that unusual?

    It's what you should expect.

    24V is the RMS voltage, when fully loaded, the peak will be 34V, fully loaded, but when open circuit the voltage will be up to 20% higher so 50V sounds reasonable.
  3. Sorry, I'm not sure what you're asking for.

    You don't need the relay? Simple just omit it and connect the load in the relay coil's place.

    What load are you planning to drive?

    You should consider using a CMOS 555 or replacing it with a CMOS IC (e.g. CD4011) or MOSFETs ( e.g. 2N7000) as the 555 draws too much current to run off such a small battery so it won't last very long.

  4. There's an error in the information. You'll need 1.5A to get 5W with a forward voltage drop of 3.3V.

    You don't have to worry about the voltage which is self-limited by the LED. The current just has to be limited so a constant current source is all that's required.

    The LM317 won't really cut it and is only something one would use if they had nothing else to spare. The efficiency at 12V with a 3.3W LED is a pitiful 27.5% and asking it to dissipate >8.7W is a lot, even with a good heat sink.

    You can buy purpose made ICs and modules for this. Here a few parts which would do what you want:

    http://www.luxdrive.com/products/buckblock-a009-led-driver/
    http://www.luxdrive.com/products/buckpuck-3021-3023-led-driver/
    http://www.recom-international.com/pdf/Lightline/RCD-24.pdf
    http://www.xppower.com/pdfs/SF_LDU08-48.pdf
    http://www.xppower.com/pdfs/SF_LDU05-14.pdf

  5. It looks fine, although I'd say C1 is probably a bit undersized to expect a ripple free output at 3A. I'd recommend increasing C1 to 68,000uF or more.

    The regulator will probably overheat and shut down, if you attempt to draw the full 3A, at lower voltage settings. A possible solution is to use a centre tapped transformer and tap changer to reduce the voltage to the regulator, at lower voltage settings.

  6. There are plenty of schematics available. You need to learn how to use a search engine.

    https://www.google.co.uk/search?q=metal+detector+schematic&hl=en&client=opera&hs=iMn&rls=en-GB&channel=suggest&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=JGkzULTLOcqw0QWaoIDwDg&ved=0CFIQsAQ&biw=1024&bih=608

    As you're obviously having difficulty with that. My advice would be to buy an inductive proximity sensor which can give an analogue or logic signal to the microcontroller. Again, a search engine is your friend.
    https://www.google.co.uk/search?client=opera&rls=en-GB&q=inductive+proximity+sensor&sourceid=opera&ie=utf-8&oe=utf-8&channel=suggest

  7. The transistors driving the LEDs form a divide by two counter which changes state on every clap. The counter is triggered by a pulse AC-coupled to the emitters via a 100nF capacitor. All you need to do is add another pair of transistors in the same divide by two counter configuration before the transistor which drives the relay.

    It would make it easier to explain if all of the components were numbered i.e. Tr1, Tr2, C1, C2 etc.

    Here are a couple of links to other websites showing a similar circuit.
    http://www.electronics-tutorials.ws/waveforms/bistable.html
    http://ch00ftech.com/2012/07/10/transistor-clock-part-2-prescaler/

  8. It's possible to do that.

    What output voltage do you require?

    A 12V transformer will only give you a maximum of 8V out.

    The full scale voltage is set by altering the values of R5 and R6 but other modifications will be necessary. You need to understand the circuit before making such changes. The original circuit contained many errors which have been corrected by audioguru, in the thread linked below:
    http://www.electronics-lab.com/forum/index.php?topic=19066.0

×
  • Create New...