ceiling fan generator current problem

Discussion in 'The Projects Forum' started by keithg, Jun 25, 2009.

  1. keithg

    Thread Starter Active Member

    Jan 17, 2009
    40
    0
    I have an LM317 regulating voltage from a bridge rectifying circuit to charge a 12v motorcycle battery. Voltage measures about 14 but current is only .03 amps. Can I simply change the 240 ohm resistor from the out pin or is this more complicated? Would a Darlington transistor increase current. Not very experienced unfortunately. Would appreciate any advise.
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    Do you have any filtering caps?
     
  3. keithg

    Thread Starter Active Member

    Jan 17, 2009
    40
    0
    Yes, 2200 50V for each coil. Output seems to be smooth. I am trying to make a pedal generator to charge a lead acid 4v battery for remote villages without power for lighting. The generator is putting out about .4 amps and 60 volts dc after rectifying. I chose a typical LM317 regulating circuit instead of something specifically for lead acid battery charging. I brought many components from the States but don't have the exact parts for several possible circuits. Would you please advise if there is a substitute for BC547?


    file:///Users/keithgum1/Desktop/lead%20acid%20Battery%20charger.webarchive

    ------BC 547

    or, please suggest another circuit.

    Last question: Is there such a thing as a current doubler? I tried a Darlington transistor to boost current but was not successful (yet). It appears we need more current and less voltage?
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    That is a transformer. A step down transformer will output a lower voltage than the input, but at a higher current.
     
  5. keithg

    Thread Starter Active Member

    Jan 17, 2009
    40
    0
    I am ten hours from the nearest electronics shop in Manila. Is there any commonly used transformer (radio,etc) I might adapt for this purpose? Would the leads of the generator be soldered directly to the transformer?
     
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