12v trickle charger

T

TheMotheMan

Member
Just wondering if anyone has tried to use the 6v output input into a dc boost converter to trickle charge a 12v sealed battery? I have come into about a dozen 12v sealed batteries used in backup lighting systems and backup systems for repeaters we use at work. I would think that when I'm not running my lights the 6v output could trickle charge up a battery long as I kept the current draw under 300mA on the 6v side. Any thoughts on this?
 
been thinking the same thing myself although i am planning on using a 6V/4Ah sla battery. got mine from radio shack for 12 bucks Yuasa Enersys™ NP4-6 6V/4Ah Sealed Lead-Acid Battery - RadioShack.com Make sure you use a Schottky blocking diode on the white wire before you connect it to anything that way current from the battery does not go back into you magneto. and you are gonna have to use a rectifier to convert the motors ac current into dc current (i think its ac coming out, should be) and then while i am at it i might as well put a capacitor or two inline so as to smooth out the charging current. as far as boosting 6v to 12v i never really do that i always just use whatever fits better with my source voltage :) although im sure google will turn up some schematics of 6vdc to 12vdc circuts. (i have a LARGE box of 12vdc sla batteries also :)
 
No need for schematics, I am just using a converter we use in a product we build where I work. I was just wondering if anyone has tried it, I would think the 6v would work just fine, I just like using 12v for the convenience that auto LEDS are 12v modules. I got the circuit built and working with current limit to limit the amt of current being pulled from the mag to an acceptable amount, thus trickle charging the battery when the current pull from the lights is below the current supplied by the converter. We'll see how it goes this spring after I get this all on the bike. Hope it all turns out looking decent :)
 
aspireonescs said:
... Make sure you use a Schottky blocking diode on the white wire before you connect it to anything that way current from the battery does not go back into you magneto. and you are gonna have to use a rectifier to convert the motors ac current into dc current (i think its ac coming out, should be) and then while i am at it i might as well put a capacitor or two inline so as to smooth out the charging current...
Click to expand...

I believe that a single rectifier diode will adequately block the reverse flow of voltage into the coil. There is no need for an additional blocking diode. What would you have? Two different rated diodes in series? Seems redundant.

No need for the smoothing capacitor in a battery charging circuit.

to TheMotheMan-
I like the idea of the 6v-12v converter in order to allow the use of the more common 12v components. Even so, I went with all 6v components for my first build in order to use the built in 6v capability. Someone on eBay is selling a 12v output coil for the HT engine. The 6v-12v converter may or may not be a cheaper/better option for a 12v solution. Let us know how it works.
 
I've got wire and a winding machine built. I'd like to know how to wind a 12 volt coil
or one that will put out 6 volts.
The coils I've made will put out 50 to 100 volt ac it will light 12 volt dc LED trailer
lights very brightly with out harming them still won't light an incandescent bulb bright enough to use. I've played around with diodes, caps, resistors etc. Not knowing much about these
things I'd like to know what needs to be made to work.
I've rewound the mag coil I can get them to run the engine but have not improved the white wire
out put. Seems the white wire has to have no more than 2.20 ohms reading over that it effects the ignition way to much kills the thing.
I've found that by using 28 gauge wire for the white wire winding it will allow the engine to idle
real slow with the lights on, but the light is dim even at higher rpms.
I've completed one coil with 26 gauge wire to test so far only on the testing rig I made it will make the head light brighter but I don't know how it will work on the engine seems to have good spark at the slower rpms. Its snowed here so running the bike will have to wait, 3' drifts in the driveway will make it way too tough to try.LOL. I hate snow!!!
any idea how the ebay coil is made? core, wire size, amounts etc.
 
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Norman said:
I've got wire and a winding machine built. I'd like to know how to wind a 12 volt coil
or one that will put out 6 volts.
The coils I've made will put out 50 to 100 volt ac it will light 12 volt dc LED trailer
lights very brightly with out harming them still won't light an incandescent bulb bright enough to use. I've played around with diodes, caps, resistors etc. Not knowing much about these
things I'd like to know what needs to be made to work.
I've rewound the mag coil I can get them to run the engine but have not improved the white wire
out put. Seems the white wire has to have no more than 2.20 ohms reading over that it effects the ignition way to much kills the thing.
I've found that by using 28 gauge wire for the white wire winding it will allow the engine to idle
real slow with the lights on, but the light is dim even at higher rpms.
I've completed one coil with 26 gauge wire to test so far only on the testing rig I made it will make the head light brighter but I don't know how it will work on the engine seems to have good spark at the slower rpms. Its snowed here so running the bike will have to wait, 3' drifts in the driveway will make it way too tough to try.LOL. I hate snow!!!
any idea how the ebay coil is made? core wire size amounts etc.
Click to expand...

To Norman-
Are you trying to create a system with a stable 6v or 12v output? If so, a battery with a rectified charging circuit is the best way to go. You are never going to get a very stable AC output without some fancy circuitry.

So you get 50-100vac off your custom lighting coil? I’m not sure how your measuring it, RMS, average, peak, etc? But that is where the problems often comes in. Try this instead: Put a diode on the output wire and run it to a capacitor positive pole. Ground the negative capacitor pole and run the engine up to operating rpm briefly. Measure the DC voltage on the capacitor. That will give you the AC peak voltage. Try the same thing with the polarity of the diode and capacitor reversed. The readings may not be symmetrical. Do not have any other lights or load connected during the test.

To determine the correct direction to use, hook the diode to the output wire and short the other end of the diode to ground after starting the engine. If the motor dies, reverse the diode and try again. If the motor just slows down a small amount, that is the direction to use.

Try a heavier gauge wire with fewer windings and see what the output voltage is.
 
6 volt would be what I'd like to make.
I use a ohm meter on ac volts to measure the voltage out of the coil that is the way I've been doing it nothing fancy might even be doing it wrong. Meter set on ac I put one lead on the wire coming out of the coil and one lead on the frame of the coil.
I wind the coils with the start of the wire soldered to the frame of the coil and wind on the windings. I've used 36 gauge,28 gauge, and 36 gauge wire. Seems to be the finer the wire the more it will put out in ac voltage.
The diodes I have are from radio shack they have a assortment pack part #276-1653
25 assorted diodes supposed to be 1 amp ? they are numbered
IN4001 to IN4007 I have no idea what the difference in them are.
the bridge rectifier I have has the IN4001 diodes in it with a 6 volt regulator.
As for capacitors I do not know which size, or rating it should be.
So I'm whizzing into the wind it looks like.
I wanted to be able to improve the magneto coil if its weak and will not idle with a light
on it. Some will and some won't but if I could change the winding where the engine will idle and run good with the lights on or off thats what I've been trying to do by rewinding the magneto coil.
I have numerous failures so far.
The extra coils I've made I did for seeing just what it would put out. Or if I could make a 6 volt
incandescent light bulb light up good enough to use with out messing with the white wire on
the engine.
I have the tools to wind a coil and wire to do it with I just need someone that knows
electronics. I haven't gave much thought to using a battery in the system . If you wanted to try one of the coils I've made I'd ship you one so you could check it out. Making the fame or core for them is a real pain so I don't think I'll be making many more.
I'm still messing with the magneto coil trying to figure out if they could be made better. If you have any ideas let me know I can wind it up and see just what it will do.
One thing I do know is any load you put on the white wire it really takes away the out put to the ignition side. I've tried more winding on the white wire and that seems to kill the ignition side. Seems that if the 36 gauge wire has more winding added to it it helps keep the engine running at idle or if you use 28 gauge wire instead of 26 gauge, but then the lights are not as bright with the 28 gauge wire.
I've found that too much 36 gauge wire will cause the ignition to go sour at high rpms.
You do not want to wind 26 or 28 gauge wire over the 36 gauge wire either it will make the engine very hateful.
I haven't tried any wire larger than 26 gauge so I might have to order some and see if it will help make the lights bright and idle good when the lights are on.
Guess I'd better stop I've high jacked this post enough.
 
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The heavier gauge wire will provide more current but it is still just a transformer for the white wire, it's still an induced voltage on the white wire (secondary winding) so you'll still need at least the same number of wraps, a larger wire just provides more current.

to Norman: I've thought about winding my own coil but I would think that the primary coil is putting out somewhere around 200V+ and this would be hundreds of turns if not close to 1000? the secondary I thought I read somewhere on this forum was in the hundreds, the heavier wire will be thicker so trying to get the same number of windings will be tougher as the magnet on the engine may need to be modified to be a bit smaller to allow for the clearance of the new windings.
 
Hey if you want to take a look at the magneto coil winding I've been trying look here.
http://motorbicycling.com/f39/winding-coil-new-wire-14619.html

I've also been messing with a coil that mounts to the back of the magneto coils frame.
Scotchmo said to try heavier dia wire less turns. I took a 8' length of 22 gauge wire and added 4 lengths of 28 gauge along side of the 22 gauge wire wound the bundle of wire onto a coil frame made from 1/8" dia steel. started up the bike and attached the 2 leads from the coil to a 3 volt light it lit up never could get it to light up that bright with a bunch of 36 gauge wire wound on as a single stand , but it would put out the high ac voltage 50ac volts at idle and 100 volts ac revved up. With the 36 gauge wire I could light the 12 volt 2 LED red light.
With the bundle of wires on this coil I can't get the LED to do anything. I didn't put a meter in it, I can later. That was one sorry looking coil.
But if I was to wind that coil frame with bundled 22 gauge wire do it neatly and wind on all I can it might be more for what we want in the way of low voltage with enough current?? to light incandescent 6 volt bulbs or trickle charge a 6 volt battery with a bridge rectifier I just don't know? I'll have to look into the heavier 22 gauge wire. I had just the one chunk of 22 gauge wire and a bunch of the smaller sizes so I used what I had on hand.
 
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