Rear light problem,Help required

Dodgy Kips motor? CDI? battery? diode? reg/rect? its all gobbledygook to me but some people understand it ask tham a question here
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marksim
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Joined: Sat Oct 13, 2012 10:32 pm
Location: York

Rear light problem,Help required

Post by marksim »

Hi guys,
really could do with some help here.
Ive a different seat unit fit on my KR1 and therefore have a small LED Stop & Tail rear light.
My problem is they dont last very long and after 3 different ones im at a loss what to do next.
It seems after a while several of the LEDs stop working and when ive taken the lights apart it seems as though some of the small resistors have burnt outr.
Have any of you got any ideas why ?
Thanks in advance
KR1S Special
Aprilia RS 270
Suzuki RGV VJ 21
Yam RD400F
KTM SDR 990
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500bernie
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Re: Rear light problem,Help required

Post by 500bernie »

Hi Mark,
Sounds like you need to sort out the correct value resistors to suit your leds and your supply voltage.
You can calculate this using the following formula:

R = (V1 - V2) / I

Where;

V1 = power supply voltage
V2 = LED voltage
I = LED current (usually 20mA which is .02A - check the spec of the ones you are using)

Cheers
Bernie
Firecracker Red and Grey C3 300
marksim
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Posts: 77
Joined: Sat Oct 13, 2012 10:32 pm
Location: York

Re: Rear light problem,Help required

Post by marksim »

Cheers Bernie,
the problem is the 3 different units ive tried have had various amounts of LEDs and the resistors are built into their circuit boards.
Just checked the info with the adverts and it says they come with the correct resistors for the flash rate
Ive also fit these to other bikes and had no problems ?
KR1S Special
Aprilia RS 270
Suzuki RGV VJ 21
Yam RD400F
KTM SDR 990
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500bernie
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Re: Rear light problem,Help required

Post by 500bernie »

Hi Mark,
You should check the supply voltage to the units (and the integrity of the earths while you are at it).
Normally LEDs and their circuits are quite forgiving in relation to fluctuation in supply voltages (within reason).

It is most likely something daft like a poor earth, causing you to draw excess current through one or more of the units (i.e. when you are braking with your lights/indicators on). A fun way to spend a few evenings #-o

Good luck [-o<
Firecracker Red and Grey C3 300
marksim
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Posts: 77
Joined: Sat Oct 13, 2012 10:32 pm
Location: York

Re: Rear light problem,Help required

Post by marksim »

Cheers Bernie :(
I also run a LED headlight if that helps you anyway in sorting the problem LOL
KR1S Special
Aprilia RS 270
Suzuki RGV VJ 21
Yam RD400F
KTM SDR 990
BradfordWebster

Re: Rear light problem,Help required

Post by BradfordWebster »

marksim wrote:Hi guys,
really could do with some help here.
Ive a different seat unit fit on my KR1 and therefore have a small LED Stop & Tail rear light.
My problem is they dont last very long and after 3 different ones im at a loss what to do next.
It seems after a while several of the LEDs stop working and when ive taken the lights apart it seems as though some of the small resistors have burnt outr.
Have any of you got any ideas why ?
Thanks in advance
There is some issue with resistors..Just get correct ohm resistors for proper functioning of these lights..
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