Lights Circuitry Modification

[Mexicano]

We have been discussing this a little bit in another thread (Capacitor), so I decide to open a new thread for this....

I have a friend with a Yamaha BW'S 100 (ZUMA), this scooter has two head lights, 30 watts each light bulb, as many other scooters, head lights and tail light only work when engine is running, the battery is 4 Ah, the head lights looks weak when the engine is idling, when you twist the throttle they go bright, my friend ask me to help him to connect the head lights and tail light to the battery, so he can have brighter head lights even when idling.

I thougt this was easy to do but, looking at the wiring, you can see this scooter has two resistors in paralell wired to the light master switch (on/off), when lights are "off" the wire coming from the stator goes to ground via the resistors, instead of the head lights, also goes to the bridge(or regulator) I guess this is intended for not over-charge the battery????

Look at the diagram:

We decide to modify the wiring and connect the head lights to a B+ wire coming from the key switch, this way, even if he forget to turn off the lights, once he turns off the key switch, the lights get off.

We were wondering what to do with the resistors, and we decide to connect them to the wire coming from the stator, the same way they were from factory when lights are off, before the modification.

Here you can see what we did:

We tested the "new" wiring and all seems to work properly, he drove home, about one hour away, when he got home the battery was discharged, he drove all the way with lights on (It's the fucking law!!), he told me that if he turn off the head lights and drive for a while the battery gets charged again.

I'm trying to figure out what is the problem here, my guess is that I have to pull away the resistors, and see what happends, but I'm afraid if I do this may I fried the battery beacuse to much charge?....I mean if he forget to turn on the lights for some reason, ALL the charge current is going to the battery, right?

Another issue is that I always thought that the stator 6 coils was divided into 2 "sets", 3 coils for lights and 3 coils for battery, BUT....NO!!!, look at the picture, this is the way they are connected:

As you can see, coils 1, 2, 3, 4 & 5 are connected to the bridge only (or regulator) but coils 1, 2, 3, 4 , 5 & 6 are connected to the lights AND to the bridge (or regulator)

What do you think?...do you think just to pull out the resistors is enough to make this work without discharging the battery??

Thanks for your inputs...

 

[adas]

aloha, Mexicano. I am thinking that the regulator will not regulate enough current to supply the battery charge, signal, horn, etc AND lights. That is why the lights are connected on the unregulated side..... correct me if I am wrong. frank

 

[Mexicano]

aloha, Mexicano. I am thinking that the regulator will not regulate enough current to supply the battery charge, signal, horn, etc AND lights. That is why the lights are connected on the unregulated side..... correct me if I am wrong. frank

Frank:

I made some test and these regulators looks like they are not a "regulator", looks like they are only a diode bridge to rectify the AC coming from the stator in to DC, something like this:

But....who knows????

 

[StepVino]

I'm with Frank on this one.

It's difficult, and probably risky doing anything without knowing
exactly the circuit in the regulator. Having said that, If you are
willing to take that risk, I would try keeping the changes you made,
but also switching the wires you have labeled 5 and 6 charging coils.

This "should" make available the extra current from the light
coil, but it would be regulated. Note that this would also mean
that a higher voltage is applied to the input of the regulator,
and could fry it.

 

[Eoin70]

the resistors are there to provide a load when the lights are not in use, if there was no current being drawn from the coils you can get a very high voltage built up from Back Emf etc,
my simple suggestion would be to buy higher wattage bulbs

the rectifier cant's charge your battery fast enough because of the huge load on the battery

 

[Mexicano]

I was looking at my Vento Triton R4i electric schematics and it doesn't use the resistors, so, in my Vento, when lights are not used, ALL the coils are charging the battery, it means that all the current is going to the bridge or regulator.

I will perform a simple test to a spare bridge I have, if it is NOT a "regulator" when I apply some 30 VAC it will only "convert" the 30 volts into DC, right?, if it is a regulator, it will bring the 30 VAC into some 13.5 VDC, right?

Will let you know later....

Thanks for the comments!

 

[StepVino]

I was looking at my Vento Triton R4i electric schematics and it doesn't use the resistors, so, in my Vento, when lights are not used, ALL the coils are charging the battery, it means that all the current is going to the bridge or regulator.

I will perform a simple test to a spare bridge I have, if it is NOT a "regulator" when I apply some 30 VAC it will only "convert" the 30 volts into DC, right?, if it is a regulator, it will bring the 30 VAC into some 13.5 VDC, right?

Will let you know later....

Thanks for the comments!

Right! But consider that it charges the battery, so it Has to be
a regulator. Have fun

Some other points to consider, if it is a regulator. I'm guessing,
from a wiring diagram we looked at the other day, that each output
of the generator puts out about 40v open circuit. You will be
doubling the input voltage, and adding about 5 amps to the
output current. The power it dissipates is directly proportional
to the voltage across it, and current through it. If you double
the voltage input, and qadruple the current, the required
power dissipation will go up by 8 times.

 

[StepVino]

Mexicano, this might work and be very simple.
Original wiring, but just add a diode going from
regular coils to light coil output. This bypasses
the regulator, and should only steel some current
at idle when light coil output is low. Don't know if the
battery would charge at idle, or what other effects might
be, but it's worth a try. Also, I "think" it's safe, but
of course can't be 100% sure. Diode should be at
least 5amps rating.

 

[Mexicano]

Stepvino:
What we want to do, is to be able of turn on the head lights even if the engine is not runing, and the only way to do this is wiring the head lights to the battery, isn't it?

I will make some test tomorrow and let you know.

My major concern is to verify this:

1) Two light bulbs x 30 watts each = 5 Ah, battery is 4 Ah.
2) Stator is 80 watts (?)= 6.6 Ah.

Theorically, the coils are able to run the lights and charge the battery at 1.6 Ah rate, right?

 

[adas]

Aloha, I run an aprillia engine (minarelli) and also one 55/60 blue headlight with an electric water pump. But I also have LED's for all my other lights, (signal, Brake Rear running light) With no problems keeping the battery charged.

frank

 

[StepVino]

Ok, sorry, I thought it was just the dimming at idle.

I wouldn't worry about the amp/hour spec too much.
I think that only means that it will supply 4amps for
one hour, 8amps for one hour.. etc. up to cranking amps.
I could be wrong though, 8amps for half hour seems like
a lot.

Anyway, I have designed many circuits over the years,
but this one has me stumped . Only way I can see so
far is a bit complicated, with 2 relays.

 

[str8dum]

why not just run the headlights straight from the battery then? Why even mess with 2 different circuits? Just unhook the AC line from the stator and the switch and rewire the switch from the battery.

 

[StepVino]

why not just run the headlights straight from the battery then? Why even mess with 2 different circuits? Just unhook the AC line from the stator and the switch and rewire the switch from the battery.

It might burn up the regulator. Don't know that for sure of course..
You'd also not be using the power from the light section of the coil,
which is needed. I think when Mexicano tried it, the battery
wouldn't charge.

I like tricky design/mod problems.

 

[Mexicano]

why not just run the headlights straight from the battery then? Why even mess with 2 different circuits? Just unhook the AC line from the stator and the switch and rewire the switch from the battery.

That is another way to do it, but my friend wants to run the lights thru the key switch, just in case he forgets to turn the lights off.

Anyways I can't unhook the AC wire from the stator, because I need it to charge the battery.
Regards,

 

[Mexicano]

It might burn up the regulator. Don't know that for sure of course..
You'd also not be using the power from the light section of the coil,
which is needed. I think when Mexicano tried it, the battery
wouldn't charge.

I like tricky design/mod problems.

That's right!, now the scooter is using the resistors, as you can see in diagram, and power from the stator is not enough to charge the battery, later today we will make some test to see voltage at battery with/without resistors, check for current, etc.

Will let you know later.

 

[Mexicano]

The Results....

O.K. this is what we found today:

When all the coils are connected as they came from factory and lights are connected to the six coil wire, the voltmeter at battery terminals is reading 13.02~13.06 vcd. at idle, lights off, at 4,250 r.pm.s the voltmeter is reading 14.5~14.8 vcd, lights off. If we turn on the lights battery drops off about 1.3~1.5 volts.

If we connect the lights direct to the battery, when we turn them on, the reading at the volt meter drops off very fast to 12.30~12.40 and keeps going down, even if we raise the r.p.m's at almost 5,000 the voltage never goes up with lights on.

We made a bench test to the diodes bridge and IT IS NOT a regulator, we applied 25 v.c.a. at the input terminals and we got out 23.5 vcd.

The reading from the voltmeter, taken direct from the coils is 15.0~17.6 vca. with no load, depending on the r.p.m's.

I have an spare coil crown, I will put on this spare crown new windings with heavier wire and more windings, let's say 30% more and will perform more test.

Regards,

 

[StepVino]

I can tell you are vey serious about this Mexicano
Hope it all works out, I'm sure it will.

 

[Mexicano]

Thanks StepVino!...will let you know about the results soon.

Regards,

 

[Mexicano]

Well, finaly today I did the re-winding to the crown (stator), also changed the wires for new ones, maybe friday my friend is coming and we can make some test.

Here you can see the crown as it was from factory, one coil is missing, I pulled this out to see how is made:

Another view, closer:

The new wire for the windings:

Almost finished:

Finished:

 

[MONZAV8]

nice job man. Looking forward to see the results of your test!