Need help with 12v charging system for motorcycle

Discussion in 'The Projects Forum' started by mazdarx7s2, Jul 13, 2010.

  1. mazdarx7s2

    Thread Starter New Member

    Jul 13, 2010
    2
    0
    Hi,

    im after some help building a 12v charging system on a honda fl250 odyssey (i know not a motorcycle but engine/electrics are the same)

    Over the past few months i have been restoring an 83 model odyssey, and i would like to add a set of HID lights, a battery and a thermo fan for the engine.
    Im more of a machanical person the electrical, so this has me stumped.

    I would like to use the lighting coil to charge the battery, and also give me a DC source for the dc fan that i have. Battery is needed for the initial current draw the HID lights will need on start up.

    I have tried using a bridge rectifier, and i can only seem to get about 1.8v dc. however the lighting coil will power a light using AC.

    Here is a link to the orignal wiring diagram
    http://www.spinreel.com/12-12.jpg

    The lighting coil normally powers a 75watt headlight and a 3 watt brake light.

    Using the bridge rectifier i 'floated' the earth on the lighting coil, to give me both ac feeds, however the voltage is low.
    The bridge rectifier is this one;

    http://www.jaycar.com.au/productView.asp?ID=ZR1324&CATID=33&form=CAT&SUBCATID=379


    Am i on the right track? or way off? please help this is doing my head in.

    Thanks in advance!
     
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    What do you mean by you 'floated' the earth?
    Does that mean you didnt connect it?

    This should be pretty straight forward.

    You will need the bridge rectifier to rectify the AC to DC, then a regulator would be nice.


    A battery charging IC should round out the major parts. A few resistors and caps to filter and decouple, and your off.
     
  3. mazdarx7s2

    Thread Starter New Member

    Jul 13, 2010
    2
    0
    By floating the earth i mean that one side of the coil is grounded to the engine/chassis. I dissconnected this and added a wire to give me 2 inputs for the bridge rectifier, i done this because i thought it might interfere with the ignition coil.

    Is it best to leave this wire grounded?
     
  4. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    no. You are going to want to connect both coil wires directly to the bridge rectifier AC pins

    The next step will be to decide if you want to regulate the resulting DC.

    As for interfering with the ignition coil, there should be no interference.

    They are physically and electrically separated.

    What voltage (AC) are you getting off the coil?
     
  5. enduro250z

    Member

    Jul 6, 2010
    69
    0
    Instead of feeding it into a bridge rectifier, you need to feed it into a motorcycle regulator/rectifier that has 2 yellows, a red and a black wire. How ever with a 75 watt AC outpu, if you convert to DC, your only going to be left with about 50 watts DC which wont be enough for HID. Although HID is 35 watts, they draw about 80 watts on start up for a short time before settling down to 35 watts, so i think you will be struggling. I would be looking at getting the coil rewound or fit a larger coil which may need a new stator plate. Yes you have done the right thing by floating the ground for DC. This works best. If you dont you have to run an above chassis negative wire to every component away from the AC chassis ground. When floating the ground, run both ends of the light coil into the 2 yellow wires in the reg/rect. Then rund the red/black to your battery. A fan will consume heaps of power. Even if you have a battery, you wont have enough power left in reserve to keep it topped up and it will go flat. i would look at some LED lighting. There are new LED lights out there now that are very very good now that rival HID. Check out www.bajadesigns.com also Google 'LED light bars'

    For 12 volt fans
    http://www.spalusa.com

    [​IMG]

    [​IMG]
    here some some usefull resources


    MOTORCYCLE ELECTRICAL RESOURCES



    STATORS – IGNITIONS – LIGHTING – COILS – REGULATORS – WIRING - CONNECTORS



    http://www.westcountrywindings.co.uk
    http://www.bettabikes.com
    http://www.rickystator.com
    http://www.rmstator.com
    http://www.ricksmotorsportelectrics.com
    http://www.electrexworld.co.uk
    http://www.electrosport.com
    http://www.trailtech.net
    http://www.trailtechproducts.co.uk
    http://www.powerdynamo.biz
    http://smallcoilrewinds.com.au
    http://www.statorsis.com
    http://www.rexcauntracing.com
    http://www.roadandraceignitions.co.uk
    http://www.uk-motoplat.com
    http://motoplatrepair.tripod.com
    http://www.norbsa02.freeuk.com
    http://www.pazon.com
    http://www.podtronics.net
    http://www.pvl-zuendungen.de
    http://www.trickdualsport.com
    http://www.classicandvintagebulbs.com
    http://www.vortexcdi.com
    http://www.hpi.be
    http://www.ignitech.cz
    http://www.zeeltronic.com
    http://www.boyerbransden.com
    http://www.pentonimports.com
    http://www.vintageconnections.com
    http://www.vehicle-wiring-products.eu
    http://www.motocicliveloci.it/inglese/catalogue/krober_uk.htm
    http://www.dynaonline.com
    http://www.dynatekuk.com
    http://www.dropbears.com/r/rewinds
    http://www.roadandrace.com.au/electrical_repairs.htm
    http://www.regulatorrectifier.com
    http://www.ktm495.mxbikes.com/motoplat.htm
    http://www.motorcyclehidlights.com
    http://www.kokusandenki.co.jp
    http://www.globaldenso.com/en
    http://www.bosch.com
    http://www.hella.com.au
    http://www.narva.com.au
    http://www.invisionsales.com
     
    Last edited: Jul 15, 2010
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