Led front headlight goes off when revved

[savage sausage]

Ive wired up a new led bulb directly to the reg/rec it powers on when idling with a slight flicker, but when the engine is put under load it goes out.

What have i wired up wrong

 

[(F5)]

Try put a large capacitor as a faux battery, say 1000uf or ideally more and 25v rated. Or hook up to a battery to check. Regulation can go screwy if it sees an open.

 

[savage sausage]

Thanks for the reply
In short the 2 wires from external genetator are wired directly into a new Reg/Rec , and the headlight wired up directly to R/R (no switches wired in yet)

so where do i put the capacitor?

 

[Leo]

so where do i put the capacitor?

after reg/rec

 

[savage sausage]

after reg/rec

So that would be on the actual wire for the bulb +
correct?

Is a bigger uf capacitor better ? 2000/ 4000/ 10,000
buyong one is no problem just want to by the right one the 1st time

 

[(F5)]

2200uf 25v will be fine, and what I've used in similar setups.. A 16v will be too close to the line but would be OK for a test. They will be polarised so + to + power.

 

[savage sausage]

2200uf 25v will be fine, and what I've used in similar setups.. A 16v will be too close to the line but would be OK for a test. They will be polarised so + to + power.

forgive me for being stupid but is that 1 capicitor leg soldered on the reg/reg end and the other on the high beam of the bulb its self?

tell you what tommorow ill add some pictures so you or anyone else can see the setup, ive used bullet connectors
crimped and soldered them all.

on a side note i got the rear led brake to work off a 9v battery to test, but it only worked when the - was on the - part of the battery l, i assumed that it would just need grounding as is? but maybe it needs to be grounded to the input/output of the reg rec?

muck fe this electrical gubbins is harder than then carb adjusting or rebuilding a top end

 

[pscook]

muck fe this electrical gubbins is harder than then carb adjusting or rebuilding a top end

I have nothing to add except that a good friend always told me "just remember it's electrical theory."

I agree that sorting out the electrons is MUCH more difficult than anything mechanical. Good luck!

 

[Neil E.]

forgive me for being stupid but is that 1 capicitor leg soldered on the reg/reg end and the other on the high beam of the bulb its self?

Best to connect the capacitor across the rectifier output the same way a battery would be connected. Observe the correct polarity as F5 has mentioned.

 

[Neil E.]

on a side note i got the rear led brake to work off a 9v battery to test, but it only worked when the - was on the - part of the battery, i assumed that it would just need grounding as is? but maybe it needs to be grounded to the input/output of the reg rec?

Depends on how you wired the system. Assuming the output of the rectifier is ungrounded, plus goes to your brake switch and then to the plus of the light. Minus goes to the minus of the light.

 

[(F5)]

Yeah. So like a battery. The output of the reg is 12ish volts +. Cap+ here. The - of cap to earth . your light is earthed I assume.

 

[savage sausage]

Depends on how you wired the system. Assuming the output of the rectifier is ungrounded, plus goes to your brake switch and then to the plus of the light. Minus goes to the minus of the light.

The output is grounded

 

[Neil E.]

In a different topic you stated that you are using the Ducati stator that has two yellow wires and a red wire. Your grounded rectifier output is OK as long as your stator red is NOT grounded.

 

[savage sausage]

In a different topic you stated that you are using the Ducati stator that has two yellow wires and a red wire. Your grounded rectifier output is OK as long as your stator red is NOT grounded.

I used just 1 of the yellow wires and the red straight into the R/R is that wrong?

 

[Neil E.]

No, that's perfect. I'm just confirming that only one side of the reg/rect has been grounded. So basically the plus from the reg/rect output goes to various switches and then to your loads. The other side of the loads are connected to minus (which is grounded).

I have no explanation for lights turning off at high RPM if you have a battery (or capacitor) in the circuit. Without a battery (or cap) the reg/rect may do strange things. Maybe the r/r you have is faulty.

 

[Leo]

This happen with halogen lamp too?
Led ohms can be too small.

 

[(F5)]

Standard setup for a Honda CR or RS with digital ign is regulator and Cap.

 

[savage sausage]

Well thanks for all the replies fellas, i'll get a capacitor bought and wired in.

 

[(F5)]

Get down to the shop and knock on the doors till the slackers open up.