7-13v ac to 5v dc constant?

Discussion in 'The Projects Forum' started by oddballmotorsports, May 24, 2016.

  1. oddballmotorsports

    Thread Starter New Member

    May 23, 2016
    Hello everyone! let me just start this off by saying, I know enough to get me into trouble, maybe a little more, when it comes to electronics. but that doesn't stop me :) anywho, I am working on a usb charger for an old 3 wheeler that doesn't have a voltage regulator, just a stator, and a light bulb. for those of you who don't know, the usual set up for a motorcycles / atv's is a permanent magnet generator producing over voltage, then a bridge rectifier, than a shunt to ground regulator. on mine its kick start, with just a headlight to run, so the lighting coil impedance is matched to the light bulb, and its done. but I want a speedometer, and some other doodads, loaded onto a smart phone, and I want to keep the phone charged. so thus the need to get a constant 5v. I would like to build a power supply that doesn't use a shunt to ground regulator, as thats just a waste of energy. So can anyone recommend a circuit I could build that would provide a constant clean dc 5v? I can solder it all together and read schematics, but as far as designing the circuit, and which components I would need thats where I'm lost. its going to be pulling off the lighting circuit, so it needs to be as efficient as it can be, as the stator output isn't that high (75w). so oh wise wizards of wires, what would you recommend?
  2. Papabravo


    Feb 24, 2006
  3. ronv

    AAC Fanatic!

    Nov 12, 2008
    You may need a cap on the input depending on how many phases your dynamo has. Then one of these would do it for the 5 volts.