Author Topic: LED Rear Light Project  (Read 37402 times)

RCE

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Re: LED Rear Light Project
« Reply #45 on: March 01, 2010, 12:14:40 AM »
Aw, come on Martin, I'm sure a 50mH inductor in there somewhere could totally eliminate!  ;)


On a serious note though,  any clues as to the origin of the spike shown up while you've been testing?


I would be interested to know if it is coming back from the modulator or forward through the brake switches, my gut instinct would be coming back from the modulator. The bike hasn't got ABS or anything has it ?

martin999

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Re: LED Rear Light Project
« Reply #46 on: March 01, 2010, 01:27:37 PM »
Aw, come on Martin, I'm sure a 50mH inductor in there somewhere could totally eliminate!  ;)
DON'T TEMPT ME!!  ;D
On a serious note though,  any clues as to the origin of the spike shown up while you've been testing?
I would be interested to know if it is coming back from the modulator or forward through the brake switches, my gut instinct would be coming back from the modulator. The bike hasn't got ABS or anything has it ?
I reckon it is radiated EMI coming from either the ignition system or the generator.  The spikes are random on idle, but when you blip the throttle the scope will always trigger on a fresh spike.  When the engine is not running there are no spikes.

zeuter

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Re: LED Rear Light Project
« Reply #47 on: March 01, 2010, 04:33:48 PM »
Martin, is she Fuel Injected?

martin999

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Re: LED Rear Light Project
« Reply #48 on: March 01, 2010, 06:08:01 PM »
Martin, is she Fuel Injected?

Nope, drip fed into four lovely carbs!

The ignition timing is by way of a signal generator rotor and pickup coil on the end of the crank.  This signal is fed together with the throttle position into a digital ignitor, then out to the coils and on to the plugs.

The generator is pretty standard with a built in IC regulator.

zeuter

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Re: LED Rear Light Project
« Reply #49 on: March 02, 2010, 04:00:56 PM »
Could be as the alternator comes on load as you blip the throttle and maybe at tick over it can't quite make up its mind and is going on and off load randomly.  especially when engine is cold and running a bit lumpy.  It'd be nice to know for sure.