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voltage reduction????

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Did I say waaaay back on page 1 to get a 10 & a 15 & a 20 just in case?

Hate to say I told you so...

Tanner Electronics in Dallas will have what you need for pennies.

:-)
 
Ok I scrounged up a old dash light dimmer (variable resistor!) and these dual color LEDs have a working range where they are bright and don't cut off of 1 volt.
Below 13 volts the brightness drops off and they start to flicker at 14 volts and shut off at 14.1 volts.

Switching to plan B for right now, may fabricate up something like I did on the rear.


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focus frenzy said:
Ratsinfratzen bracken bah humbug!!! (insert image of hair being ripped out and objects smashed)

Well radio shack only had 10 ohm 10 watt, or 1 watt or smaller so I decided 1 10 watt 10 ohm for both would work and it does reduce running voltage to the lights down to 14.17 volts but the lights still cut off!!!
Turns out the cut out is at 14.1 volts at the light!!!!

They are going back!!!!


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Click to expand...

PLEASE RE-READ MY POST #12
 
Please note: as ohms goes up, voltage to led's goes down OR
as ohms go down, voltage to led's goes up
 
Ok using just a resistor is not going to work with the narrow usable voltage these light work with so I am making this voltage regulator.
LM7812_DIY.jpg



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Leon: I stayed away from that circuit but am glad you're not afraid to build it. You should do great with it as long as you don't exceed recommended power dissipation. Good luck, good wiring! As always in wiring electrical: neatness counts.
 
I haven't followed much of this thread, but it sounds like you only need to loose a volt or so, is that correct? When you pass current through a normal diode you have about 0.5 volt drop across the diode, so why not just connect 2 diodes in series and connect them between the positive supply and your circuit? That would drop the 14.5 volts to something around 13.5 volts, very little heat will be dissipated by the diodes and your circuit will be back in its normal operating voltage range? Why go to the complexity of adding a full regulator and having to mount it on a heat sink, etc?? Have i missed something? How much current does your circuit require (Less than an amp as you are looking at the 78xx family)?

Gary
 
Going the regulated route because these lights have a narrow operating range on voltage, enough resistance with engine running is to much resistance with engine off.

I thought I had found a way around the issue with a differant light from a different company but it had the exact same issue.
I will make this work if it kills me!!!!


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Are you sure REGULATED 12 volts is the level you want fed to the lights? Or is that as close as your design criteria will allow? Inquiring minds want to know;-)
 
Well, aint life wonderful! A fast google on + regulators shows 12v or 15v,nothing in between:tears:
 
BTW, I suggest those capacitors be polarized electrolytics with a 105 centigrade rating and also a low ESR. That will ensure high quality last almost forever components. You may also want to specify plastic tab on body so mounting wiring is easier. My .02, good luck!
 
Plastic tab on the capacitors?


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on the regulator. glad you asked as my research shows different specs for various regulator mounting configurations. have been reading customer reviews on your Radio Shack regulator per the part number you supplied. you should too. NTE posts[multiple specs] them. go here: http://www.nteinc.com/Web_pgs/Positive.html gud luk!!
 
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hmmmm it says it requires at least 2 volts higher input voltage to work and the 12 volts even output is actualy to low, 13-13.5 would be Ideal so I did some searching and found DC-DC adjustable regulators but they require 1.5 volts or higher input.

hmmmmmm gonna do some more thinking.
 
Leon: looks very promising! As long as the min input volts are met, shud work. Their specs say 3 volt min in, so GO FOR IT!!! Try it and see. You saw if run at max current[1Amp] or max power[10Watts] it requires air flow across it for cooling[or it WILL self-destruct]. Also, the adjustment is backwards as you have read. Should be cheap enuf to try. Great research!!!!!!!!!! Happy wiring!!:zen::sun::trust:
 
They also make one with the same voltage range but rated for 3 amps output so I ordered it instead so I can seal it up to keep water from getting in.
As low as the load will be it should stay nice and cool sealed up.


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EXCELLENTMUNDO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:clap:
 
You can use a simple voltage reg circuit. Seeing that you are trimming just a few volts, minimal sink is needed. I am at work so don't have my stuff with me but will post once I get home. You also don't want to over volt leds as their life drops exponentially. As to the current change with volt change, that is typical with leds as they are current controlled, not voltage controlled.

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You know what.. let make this easy. I am assuming you measured your bike at the battery, right? Try measuring at the bulb. I bet you get more than a volt drop by the time its there.

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Actually very little drop, I am powering the lights from the headlight circuit and the only load there is what little is needed to pull in the power relay for the HID headlight and when on high beam the led high beam indicator and the pull in high beam solenoid.

Admididly this is a whole lot of trouble just to add cool color changing running lights.


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Your not too far from me. When are you wanting to install these lights? I can make you a voltage regulator for like 2 bucks (covers parts) and all you need to do is wire it up. Or if you know how to solder I can send you a parts list. Up to you. Tell me what voltage you want on the end. I have parts right now for 11.8xx volts, plus or minus 5%. This is what I am running for my givi tail bag tail lights. Just let me know what ya want. I plan to be at hico if you wanna make it out there and can give it to you then


Dur, just realized you will be out there. Lol
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