Stable Power Source

[moridin]

This will require the help of someone with a) a multi-meter, b) a KDX200, and most importantly c) nothing to do.

I just got my brake light setup tonight with the LED lights - and WOW is it bright! The LED only uses about 1.5 watts with the brakelight and .7 with the tail.

That leaves me a few extra watts for my GPS - but I am concerned that the voltage might fluctuate too much.

Can anyone with time - check the voltage extremes on the tail light power (or any power after the regulator) for me? Or easier - does anyone know off the top of their head how close to 12v the post regulator power is.

Cheers to all,

sean

 

[canyncarvr]

Your a US type? I presume from your location note.

The mention of a brake light gives pause......

The 'H' kdx runs on AC.

Doubt your GPS would like that much.

In any case, you notice how your lights stay nice'n bright all the time? Of course not.

I run my GPS on batteries when I carry it around. How about that?

 

[moridin]

After the rectifier/regulator - it is 12v - at least the bulbs are 12v front and rear. That is where my power is tapped from.

I checked the specs - and the LED tail/brake is .4/1.8 watts. Not bad for a light that blinds you from the rear.

The hyraulic pressure switches installed very easily - so I have a pretty factory feel.

FWIW - why does it give you pause?

I agree - will run the GPS of battery. I found some small 12v gel cell batteries that are rechargeable and only weight a pound. That would provide the kind of life I am looking for - and also eliminates using batteries - which causes blackout problems on my GPS. I think it would be easy to mount one of these setups int he headlight shroud and run my cigarette lighter right to it.

sn

 

[canyncarvr]

Your bulbs may well be 12v. Most are. Mine are.

That doesn't change the fact that your kdx (again, 'H' series/US anyway) are not, !NOT! DC (direct current).

They are AC (alternating current).

Lithium batteries are quite light (compared to alkaline for example).

The pause part comes from the brakelight mention. Such is common outside the US..but not so much IN the us. Yeah..dualsporters and some easterners nothwithstanding.

Your basic one-each dirtbike (kdx type) doesn't have a brakelight or the switch to run it.

Made me wonder if you were talking about an overseas kdx...and some of them have rectifiers (not regulators).

Something to keep in mind: The regulator is PAST (literally and electrically) the headlights. It's a possiblity that something 'tapped in' at the lights could well blow up if you lose (or disconnect) the red wire (again..in the 'H' model) wire that goes to the regulator on the way to the taillight.

Yeah...would still require a ground..but depending on how the 'after'part was wired in, you may have grounded it in the process. Unhook that red wire and P-O-O-F..there goes your (in this case) GPS.

 

[moridin]

Thanks for the info - I will stick with just the light.

I noticed when I used a stadard 1157 tail/brake light bulb that the headlight dimmed to nothing when I applied the brake. That is why I switched to the LED.

The LED draws next to nothing for power and is VERY bright.

This LED is the 1157 equivelant and seems to work well. Any reason why I cant make this work? Seems to be fine now.

I could always order the bigger stator and run a standard 1157 bulb (I think). This just seemed easier, cheaper and brighter.

Sean

 

[canyncarvr]

RE: 'Any reason why I cant make this work? Seems to be fine now.'

Thought it already was working....

As long as part of your brakeswitch add-on included a socket for a dual filament bulb (like the 1157 is), you just plug the thing in. Well, after you put on the associated parts.

OEM is a single filament. BTW, the oem headlight is a dual filament piece. If you blow out one, you can tag a piece of wire across the contacts and use the 'spare' filament.

Some have modified the headlight socket so they can merely turn the bulb 'around' to get to the other filament.

The led unit I used had to be modified a bit to fit the socket. The pins on the base were a bit 'off'...had to file 'em some.

It'll work fine. Well, if you refrain from a bit too much wheelie that tends to tear the rear fender off...along with the wires that go with it.

.......not that I'd know anything about that. ;)

 

[LIDODAVE]

What's up, mo'; greetings from sunny Long Island (15 degrees F)!! Curious as to what brake lite setup and general DS equip you're running. Always trying to improve my machine...
Dave

 

[kmccune]

If he has an LED light and it is NOT going poof then he has DC like he states and not AC! AC will blow an LED in less time then it takes to say poof!

Kevin

 

[G. Gearloose]

Originally posted by kmccune
If he has an LED light and it is NOT going poof then he has DC like he states and not AC! AC will blow an LED in less time then it takes to say poof!

Kevin

Wudjya mean? its a diode! its self-rectifying...and thre are current-limiting resistors in those things, its not a direct short when forward-biased.

 

[canyncarvr]

The led units you buy for such application have a voltage regulator (it's probably current limitation stuff you see, as G'loose says) in them, is my understanding. There's certainly more to them than some leds.

Besides, my bike is certainly ac (or, I run on no volts, cuz that's what I get when I measure it DC-wise...and my o'scope sure has a funny wiggle to it! ;) )..and the led unit I have works as long as I keep the wires connected to it.

So, poof! :)

...and there isn't enough poop on the reverse bias side of things to blow up anything.

 

[moridin]

What kind of peak volatge were you showing?

I am guessing these bulbs will hold out to 16ish volts before poofing. The headlight seems to do fine at whatever voltage. i am guessing the range is 11-16 - sound about right?

Seems to me that the LEDs would better at small excursions above 16v than a standard bulb would.

Correct me if I am wrong - but I am running a 30 watt bulb up front, a 1 or 2 watt tail/brake puts me at around 32 watts. If I recall - I read somewhere that if you are running sub what your stator is capable of producing - the liklihood of straying outside the voltage norms is much less. I am hoping this will keep things from going poof. Wonder how many times pook can be used in this thread.

 

[kmccune]

Originally posted by G. Gearloose


Wudjya mean? its a diode! its self-rectifying...and thre are current-limiting resistors in those things, its not a direct short when forward-biased.

your right I was thinking of higher voltage situations with-out a step down transformer. In the attached pic I have proven you correct, with the proper AC input diodes can be reverse biased with out poping.

Rats I hate being wrong :whiner:

 

Kevin

 

[canyncarvr]

This from what I recall (couple years back)..but the ac runs around 12v I tink. 'Peak'-ing isn't the issue if your regulator works.

The oem liting coil is good for about 40 watts. As long as you're running the oem lites you are fine. The problem comes in when you switch to a dual headlight shell, or want to add three amps of grip heat. ;)

....or an 8-track stereo setup.

re: 'I read somewhere that if you are running sub what your stator is capable of producing - the liklihood of straying outside the voltage norms is much less. '

Well, yeah. That's kind of a bonehead statement. Maybe they should have followed THAT with, 'Trying to run way over what your system is capable of putting out will increase the liklihood that the voltage will go below norms.'

Really??!!

But that 'straying' they are talking about is down not peaking, of course.

 

[canyncarvr]

Re: the gif

This brings to mind a thread of way back...and my complaint about a full wave rectifier 'wasting' a lot of power.

That's what the gif shows when only the + side of the bridge is used for anything.

You could use the whole thing. The - side of the bridge would work just as well for something like a lamp.

Might confuse electronic stuff (spark boxes and that 8-track setup) a tad. ;)

 

[G. Gearloose]

Hey no sweat, we all oops now & then!

In a related topic,
Since its an inductive world, wonder if it would be benificial to smartly apply a cap in the charging circuit somewhere, to do two things..
a) improve the power factor (minimize the current lagging the voltage)
b) harness(or minimize) the waste when current is dumped to ground (crude shunt regulation)

any thoughts?

 

[bleedngreen]

My apologies for not saying so sooner, seems my manners temporarily escaped me, but Hello my fellow KDXers, I've gotta say what an excellent site this! Been ridin a KDX since '85 (a 1980 kdx 175). That bike lasted 10 years with me and always gives me warm fuzzy thoughts when I recall our magical moments together. I have to wonder if it still lies on that hill somewhere in Northern NJ, third gear blown, piston fused to its muddy-finned cylinder, left to become one again with the earth from which its elements once sprang... Next was a 1990 200cc, rock solid reliable, which then gave way last summer to a virtually unridden '99 kdx220; still had the nibs on the knobbies. I came up with a home-brewed dual sport setup and did the Vermont reggy thing because NY no longer allows conversions of off road vehicles to street legal status. Got the carb and head RB'd and along with an FMF K-30 pipe and Dunlop D603 rubber and now I got me an extremely versatile 2-stroke I can ride just about anywhere without legal hassles, that is also rock solid reliable--and still absolutely rips!
Now that I got that off my chest, moridin, I too am using an LED stop/taillight
setup. It's lasted over 6 mos so far w/o going POOF and yes, it leaves much more juice to run other stuff. Only prob is that it IS AC current --unless you replace the stock regulator with some sort of rectifier. Had a chance to measure regulated voltage, maximum volts were 11.42, regardless of rpm.
Hope this helps some and all apologies for the long post.
Dave