Bridge Rectifiers

Discussion in 'Electrical' started by 570rm47, Jun 22, 2014.

  1. 570rm47

    570rm47 Member

    Over engineering??????

    I have been playing with my bike lots to stupid amounts but my lights still suck!

    There was the diode bridge rectifier hooked up to my NZ$3 led headlamp, it then became 2 headlamps with old cell ph batteries it was close but not quite there. Its brightness just didnt quite cut it at max speed when there was the tiniest bit of fog rain etc and I am required to have a tail light now. The batteries also caught fire when someone kindly turned off my lights at the library while parked, i just started riding without something to use the power the lithium polymer batteries um got real hot. lithium polymers dont like extra charging.

    So options
    1. Continue using dolphin torch with incandescent bulb wired directly to white wire
    2. Expand on old diode bridge rectifier circuit and use some zeners and caps to stop fire
    3. Make Light Emitting Diode bridge rectifier and dump leftover electron flow to battery for tail light
    4. Mosfet Bridge Rectifier for real low voltage drop
    5. Build total electrics from scratch including rectifier for both coils and dc-dc cdi.

    1. It is crazy that the odd person notices that the light runs off the engine and is amazed they think its awesome. However I had better lights much better and they were not quite good enough.

    2. I am tempted just for the experience but well the voltage drop is as high as 3 volts sometimes, I only have a DMM but this is crazy considering the most i have seen come put of the white wire is 7.96 volts and that was with it ringing out to the limit of engine vibration i can handle while riding top speed.

    3. Must do who cares about voltage drop if my diodes are lighting, comments pointers please. I dont think all the voltage drop is a consideration and near as i can tell reverse breakdown voltage in leds is more than enough for what our white wire provides when chosen correctly. Has anyone tried this i have seen reference to it but not a mention of any one trying for real, will leftover electron flow be enough to charge a battery/

    4. This is one of the over engineered options but im doing it just because i think its cool and it shouldn't cost much anyway that voltage drop can mean so much more if you are into the extra electrical mile.

    5. Oh YEAHHH!!!!! how to combine that aftermarket add in coil idea with the standard coil to make a 3 phase magneto then mosfet bridge rectifier and dc-dc digital cdi If only . if i did figure this out would totaly sell this along with my imaginary fuel injection for the ht engine.

    Anybody have any other solutions i got an awesome aeg battery drill with dead batteries !

  2. jaguar

    jaguar Well-Known Member

    don't rely on the white wire to supply enough juice for decent lighting
  3. Sgt. Howard

    Sgt. Howard Member

    Read "the $5 headlight revisited" sticky- I am currently experimenting with cheap rechargable penlight batteries with good results, and give all the particulrs for a bridge rectifyer operation (which I call a 'hotbox'). Works just dandy
  4. 570rm47

    570rm47 Member

    Jaguar hard advice to ignore

    Title says it all out of all the info i have been able to devour the jaguar CDI is hands down the most appreciated motorized bike device who can argue with results, I am however funds disabled when it comes to my bike (the boss/accountant/wife is still a little touchy about the $1000 of brewing equipment that we purchased so I can make my own fuel the bourbon by product does however have a very calming affect) so I am yet to experience it for myself
  5. KCvale

    KCvale Motorized Bicycle Vendor

    Well, the white wire is not your friend, and you don't get 'free' power from it, in fact it is very expensive in power loss.

    You could just quit dinking around trying to pull juice from your little 2-stroke motor and just get a real light for under $18 delivered.

    1200 Lumen Cree T6 LED with a 8.4V lithium pack, mounts and charger.

    Lights like this are a staple around the shop, not so much for night riding but for test riding, nothing besides maybe a helmet is gonna help more than a bright daytime strobe light to prevent injury but really lights up the road.

    That particular light is good for about 3-4 hours on highest intensity but for just flashing the thing will go all day.

    I went down your road a few years back and learned the hard way.
    There is no 'free' power'.
  6. Sgt. Howard

    Sgt. Howard Member

    I have four bikes currently running head/tail/brake lights off the white wire, one with head/tail/TURN/brake full function (battery used on that one, white wire charges it through a bridge rectifier). There has been no noticeable power loss. Great visibility and reliability as well. All done on the cheap. I believe I even included my source of electronics in the sticky- I stand no profit in this information. I have proven it can be done... I have proven it can be done cheaply. One bike has been running for four years, most of that time with head/tail/brake lights. All LEDs.
    I don't doubt that the CREE T6 is an awesome headlight, but it is not your only choice... and, what I have designed includes more than a headlight.
    I recently upgraded to a 10 LED head for the headlight... big difference.
  7. HeadSmess

    HeadSmess Well-Known Member

    me be using two MR16 4W led downlight fittings, took out the internal circuit and wired em up in series(6v each, these things were my path lights for a year before, retired when internal switchmode PS fried due to weather etc, otherwise no need to remove, and then wire in parallel and run on 6-12v)

    i discovered that they do not need the fancy finned heatsink they come fitted into, the flat alloy disc they are mounted on is more than adequate. doesnt even get warm. has convenient screw hole too.

    small 2ah 12v gel cell, stays lit up for about 3 days.

    they make people flash me if pointing too high because they are BRIGHT. seeing things is not an issue. thats 8X 1W leds, with 60`angle lenses

    coupla multiple LED strips down each seat stay, red of course for the rear

    night riding, other than the temperature, is now extremely enjoyable :)

    probably cost me less than $20 if i bought everything new this time round... finding the mounts for the lights that can take the abuse (vibration) and be pointed the right way is the hard part. (i didnt simply put a screw through the lens, alloy mounting disc and into something like timber or another piece of alloy, im only thinking of doing that now!)

    P.S. i had success with one magneto using the LED directly on the white wire, and the light strobed with the speed one did, quite nifty. but every other magneto, no go. i believe something to do with direction of windings therefore polarity of back emf, is all rather complex and i simply shrugged and fitted the gel cell...
  8. HeadSmess

    HeadSmess Well-Known Member

    throw the lions and lipos in the bin where they belong.

    great for model planes and cars, phones, whatever.

    they have finnicky charging/discharging demands, the voltage must remain at EXACTLY 4.2 per cell at charging. and go no lower than 3.6 or something else they explode... and lithium is a bit like sodium...BOOM! (the resistors/capacitors required to make high accuracy chargers are quite expensive...0.5 %? not commonly stocked. else you use an expanded scale DMM and select your own from the handful you bought)

    noticed the resurgance of nicad packs for trade-use cordless tools? tradies are sick and tired of liion technology...expensive and they dont last. nicad may wear out but they allow one to drain every last drop out of the battery (great when youre up 4 stories and the spare battery is down there on the ute and theres only two screws left to go...) and nicad is relatively cheap. can also be easily repacked with hi quality cells that double, even triple the Ah rating of the standard cells...

    and nimh is another kettle of fish entirely.

    lead acid is my choice. charging is dead simple, and they be cheap cheap :)
  9. Sgt. Howard

    Sgt. Howard Member

    Yea, SLA is what I started with because it is cheap, reliable and a known quality. I am trying NiCad for the bulk/weight factor. I have one system that is three years old and as robust as ever, complete with turn signals. I find the demands of the flasher require a battery operate, so that's why it is there- other systems that are head/tail/brake only work off the magneto alone- no switch for the head/tail, if the motor is running they are on.
  10. butre

    butre Well-Known Member


    I haven't had any problems with visibility. it's a 4 LED headlamp of unknown brand I got from the flea market for $8, the tail light is a red clearance light from auto zone that was $6, and it's powered by a 12v motorcycle battery that I got off a wrecked honda for $15. I've had that setup since February and the battery hasn't lost a hundredth of a volt yet. I've also got 2 round clearance lights for turn signals, a turn signal flasher unit, and a motorcycle horn off that same honda. total investment is $54 and I couldn't ask for a better system
  11. HeadSmess

    HeadSmess Well-Known Member

    grrrrr..... having issues with not only TAKING pics of lights, but uploading(this is my 3rd attempt)....hmmmskies.

    i tried my best!


    this ones just so you can see why theres so much light BEHIND the front lights... tis made from finned extrusion for heatsink purposes... just the way they come!

    yeah :)

    oooh, ill find a link...

    the ones i bought cost about 1/4 of this, just the first ones i find this time round ;)
  12. HeadSmess

    HeadSmess Well-Known Member

    actually... i really should start making mounts as that is the hardest part to get RELIABLE. you know, nice solid clamps, not flimsy plastic or cable ties... anyone interested? id do twin heads (8W) for, lets see now...$30 for starters. (ill probably be losing out, but hey) all cnc alloy, of course ;) pm me :)
  13. 570rm47

    570rm47 Member

    I wonder how hard it would be to wire up something that ignores a second pulse at the cdi kind of like the ecu in this thing and just install a second magnet in the flywheel a second pulse worth of extra juice what would this do to our poor little engines could we scavenge that much extra??