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Discussion Starter · #1 ·
Hi to all,

I am trying to convert the cbf125 to DC so I can use LED . The yellow wire coming of Honda's bridge rectifier has AC or DC pulsed ? I am not sure about it. When I connect a multimeter to the headlight connector when set on DC I get about 8V and drops when revving the engine slightly and when set on AC I get about 12v and rises up when revving.
I connected for test purposes a 4 diode bridge rectifier to the headlight connector and I get only DC.

Anyway I am planning to use the 4diode bridge rectifier after Honda's regulator so it converts the current to DC and then use a boost buck convert 8-40V to 12V10A which will keep the voltage at 12V stable.
My problem is that I am not sure about the wiring , if you could take a look at the diagrams and help would be great.

Stock wiring diagram
Product Schematic Rectangle Font Parallel


Diagram with the modificition
Rectangle Schematic Font Parallel Engineering
 

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See that thing at the top right labeled regulator rectifier (y) already has one.

Plus an LED is a light emitting diode, it illuminates due to reverse bias voltage and that can come from AC or DC. The diode doesn't know any different, all it needs is a load it can handle.
 

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Your bottom diagram is a waste of wiring.. any and all loads can be drawn off the battery voltages supplied to the keyed ignition switch.

The red/white dotted line coming out of the rectifier is a 12v line. your system is 12v, all bikes use an AC to generate power, then has a R/R to rectify it to DC and then regulates it.

You can do one or the other:

Run a direct "fused" power wire lead from the battery with a seperate on and off switch, and then just attach a ground to the frame. (you need a switch to turn off in this method)

or:

Tap into the power wire coming "out" of the ignition switch (this wire is direct battery voltages) and then run a ground to the frame. this method gives you the key to turn off the added accessory.
 

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Discussion Starter · #4 · (Edited)
See that thing at the top right labeled regulator rectifier (y) already has one.

Plus an LED is a light emitting diode, it illuminates due to reverse bias voltage and that can come from AC or DC. The diode doesn't know any different, all it needs is a load it can handle.
I dont understand ..When I put the additional rectifier I get ONLY DC ..not ac at all. Why honda's regulator doesnt provide only DC?
Also I have tried a few LEDS , they do not work ..they flicker like hell and burn out.
 

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Discussion Starter · #6 ·
Your bottom diagram is a waste of wiring.. any and all loads can be drawn off the battery voltages supplied to the keyed ignition switch.

The red/white dotted line coming out of the rectifier is a 12v line. your system is 12v, all bikes use an AC to generate power, then has a R/R to rectify it to DC and then regulates it.

You can do one or the other:

Run a direct "fused" power wire lead from the battery with a seperate on and off switch, and then just attach a ground to the frame. (you need a switch to turn off in this method)

or:

Tap into the power wire coming "out" of the ignition switch (this wire is direct battery voltages) and then run a ground to the frame. this method gives you the key to turn off the added accessory.
I already have a switch taking power from the fusebox using a "fuse thief" to power my "fog lights" . If I connect everything to the battery it will put a lot of stress , already when I am stopped and I use the turn signals with the fog lights I can see the fog light dim a bit .
But the red and white is for the battery I want to change the original harness as little as possible thats why I am trying to do it like this .
 

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I already have a switch taking power from the fusebox using a "fuse thief" to power my "fog lights" . If I connect everything to the battery it will put a lot of stress , already when I am stopped and I use the turn signals with the fog lights I can see the fog light dim a bit .
But the red and white is for the battery I want to change the original harness as little as possible thats why I am trying to do it like this .

If you take directly from the R/R, you will limit the amount of power going to your battery.

So you take the power from the battery as every other bike in known existance does so you dont prevent your battery from being under charged. this will leave you stranded likely from a low power battery.
 

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Honestly, if you want a motorcycle that is 100% LED buy a new motorcycle. You're chasing things you don't need, all an LED light needs is a resistor of the right size and the right size is dependent on the current draw of each of those custom LED's
 

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Discussion Starter · #11 ·
If you take directly from the R/R, you will limit the amount of power going to your battery.

So you take the power from the battery as every other bike in known existance does so you dont prevent your battery from being under charged. this will leave you stranded likely from a low power battery.
Why ? I will take from the yellow wire which is for the lights now and it has AC . The only difference will be that the current will be converted to DC , I dont see how this will limit the power going to the battery.
 

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Discussion Starter · #12 ·
Honestly, if you want a motorcycle that is 100% LED buy a new motorcycle. You're chasing things you don't need, all an LED light needs is a resistor of the right size and the right size is dependent on the current draw of each of those custom LED's
Thanks but you dont think I will achieve the lighting system to be 100% LED with the modifications I am planning to do?
 

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LED flickers because it has no latency it's a solid state device
and the power coming out of your coil is very inconsistent as it seems you have a single phase alternator.
If you power the LED devices off the battery the battery would regulate the DC or alternatively you might add a condenser to the circuit to smooth the power, because a condenser acts much like a battery in the most simple sense.

You can do it if you want to become an electronics geek, no problem.
... at the moment you are doing it all wrong you are adding diodes to power diodes.
 

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Discussion Starter · #14 ·
So do you think my modification diagram is correct ? I am mostly concerned about the grounding if its correct or should I use the green wire coming out of honda's regulator.
 

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You still have not answered the type of led you have question.

the yellow wire is the factory AC lighting wire. yes its for lights, but this is a single phase AC altinator. which means when your rpm drops, so does the power voltage.

The better step up version of your system has a seperate lighting coil. yours uses the same power generated to run the lights and the charge to the battery.

Notice the lower right "alternator" it only has one wire (white) this is the "only" output it has, the green is ground.

So you either have to use low voltage AC leds, or you have to use the 12v side and run new wires.
 

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Discussion Starter · #17 ·
You still have not answered the type of led you have question.

the yellow wire is the factory AC lighting wire. yes its for lights, but this is a single phase AC altinator. which means when your rpm drops, so does the power voltage.

The better step up version of your system has a seperate lighting coil. yours uses the same power generated to run the lights and the charge to the battery.

Notice the lower right "alternator" it only has one wire (green) this is the "only" output it has, the white is ground.

So you either have to use low voltage AC leds, or you have to use the 12v side and run new wires.
I think I did..anyway
I have some h4 nighteye 25w which I may use but my purpose is to use led lights everywhere ( position light,headlight, speedometer , rear ) .
"So you either have to use low voltage AC leds, or you have to use the 12v side and run new wires."
Would you mind explaining this better or show it to me on the diagram ? Thanks
 

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You bought a set of LED car headlight bulbs and plan to power it off a really dirty power supply. I can see why you had them flicker and burn out. All that black box stuff you are trying to add is a cleaner power supply. Your headlight has a reflector that was not designed for a car LED headlight bulb, it was designed to reflect a glowing chunk of carbon, it will never project right.
You're going to spend a ton of money you should be putting into chains brakes and tires.
 

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Ok, look at the altinator in your diagram (top one)... the green is ground... the white is AC voltage that when tested will not excede on this single phase alternator 20vAC (max rpm)

You see the curly thing in the middle.. thats a "single phase" AC coil.
See on the bottom the ground (green wire) this is the ground for the alternator/ststor mount base.

Font Parallel Circle Symbol Slope



This green wire is shared by all componets in the system. (follow the wire from here and you will see it goes to all lights)
as well as the R/R. again this is a ground.
the white wire here is the "single" power output. (most bikes today have a 3 phase/ 3 wire)

Notice how this white wire stops at the R/R... Now here is where you need to confirm with a voltage test. the wellow coming off the R/R is some times "pass thru" AC, meaning it just passes thru the r/r un changed. This wire will only go to "some" lights, notice how the rear signals do not share this wire just the tail/brake.


Following me so far?
 

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Discussion Starter · #20 ·
Ok, look at the altinator in your diagram (top one)... the green is ground... the white is AC voltage that when tested will not excede on this single phase alternator 20vAC (max rpm)

You see the curly thing in the middle.. thats a "single phase" AC coil.
See on the bottom the ground (green wire) this is the ground for the alternator/ststor mount base.

View attachment 70194


This green wire is shared by all componets in the system. (follow the wire from here and you will see it goes to all lights)
as well as the R/R. again this is a ground.
the white wire here is the "single" power output. (most bikes today have a 3 phase/ 3 wire)

Notice how this white wire stops at the R/R... Now here is where you need to confirm with a voltage test. the wellow coming off the R/R is some times "pass thru" AC, meaning it just passes thru tue r/r an changed. This wire will only go to "some" lights, notice how the rear signals do not share this wire just the tail/brake.


Following me so far?
Yes .. please continue ! By the way I understand that the turn signals and the rear brake light when is pressed is getting power from the battery...also the neutral bulb.
 
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