Headlights blink when I wear heated vest on motorcycle

I bought a heated vest from Gerbings which draws about 77 wats or 7amps
of 12V power. It has this low tech thermostat that keeps turning on and
off every second or twice a second to regulate the power that goes to
the vest and thereby the heat. There is an LED tha blinks on and off
that is the indicator. If you turn it up it just blinks faster until it
goes full solid (no on/off).

The problem is that when it is going on/off my headlights lose and then
gain brightness. Its probably the shock or surge when the circuit is
turned on off on and so forth repeatedly.

What kind of circuit could I use to prevent this? I am pluggin into the
cigarette lighter called a BMW power outlet.

Do you think this would damage the alternator or battery if I leave it
like this?

This is the vest: http://www.gerbing.com/divmc/clothing/jl.html

This is the temp controller.
http://www.gerbing.com/divmc/tempcontroller/port.html

Any ideas would be appreciated.

 

What model of motorcycle are you riding? My BMW 1995 R1100R has a 50
amp alternator that regulates the battery voltage very precisely, in
spite of load changes. If you are overloading the alternator with the
7 amp load, you must expect the voltage to fall when the heater is on
and return to normal when it is off. But a 7 amp load would be a non
event on my bike after a few milliseconds. Perhaps your alternator
needs new brushes.

 

Low-tech solution: wire the outlet via a more direct route to to the altenator.

hi-tech solution: dump the low tech thermostat and go with one that does
pulse-width modulation or similar, although at 11A that'd be non-trivial
(not a beginners project anyway)

it's using about as much power as your headlight probably uses, so on a
well-egineered machine like the BMW i'd say no.

 

Im riding a Triumph Bonneville America 2004. I doubt the alternator is
bad.

But if you had something flickering on and off every second drawing 7
amps wouldnt you be noticing it on your bike?

Do you think a plain old variable resistor would work. Like the ones
they have in houses for dimming lights?

Thanks

 

<<Low-tech solution: wire the outlet via a more direct route to to the
altenator. >>

I have to look at the schematic to see how this thing is routed. But
that may be something to try.

Thanks

 

Yes, unlikely for such a new bike.

I wear heated clothing all winter and have never noticed any effect.
My vest has an electronic on off control based on temperature at one
point in the vest, but the cycle time is in the 10s of seconds. Same
with the gloves. My helmet heater is continuously regulated besed on
PTC thermistor heater elements. No cycle from them. But then, my
alternator is large enough to run 4 halogen headlights and more. BMW
finally faced the fact that people want to add all kinds of electric
gear to their bikes and designed in a capable alternator.

I think you should first check up on the alternator spec. It may be
designed for the current the bike uses, and little else. If this is
the case, you could look into a switching regulator that converts high
volts at low amperes into lower volts at higher amperes with an
adjustable output voltage. That would eliminate the visible cycles and
also reduce the current load, once the heat reached equilibrium and you
turned the control down from maximum. But even if you just altered the
present design (assuming it uses a mosfet switch to control the
current, not a contact) to make the timing cycle very short (a few
milliseconds per cycle, say, for 100 or so cycles per second) you could
eliminate the visible flicker pretty well. The LED would appear to be
on all the time, but with varying brightness.

 

Wire a heavy load to get its power as directly as possible from the
battery, as when installing a headlight relay on an old car.

 

You need a new, higher capacity battery and a more powerful regulator
to handle the added load of your jacket. Or, you could be stoic and
consider that you've added a headlight modulator at no extra cost.

Ride safe.

 

Ah. A Triumph. Did you know you can buy smoke in a jar for Triumph
motorcycles? It's for putting back into the electrics after the
original smoke escapes. Seriously, get the bike checked out, you
might have a dying battery, or some other malfunction of the
electrics. FWIW, I ride (perhaps I should say "store") a '98 Triumph
Tiger, so I feel your pain.

 

Wow, that's pretty stout for a motorcycle. 32A is common for a modern
geezer glide Harley, AIUI my Sportster only has a 22A system. That's at
max output, not what you get at idle speeds. I could see where a 7A
load toggling on and off might be noticable.

Hmm, brushes? I don't know how yours works, but mine has a multipole
stator with a permanent magnet rotor that surrounds the stator sort of
like a brake drum. That part operates in scalding hot oil. The wires
come out of the engine and lead to an external voltage regulator that
contains, I assume, a bridge rectifier amongst other goodies. Perhaps
you have a generator?

 

variable resistors aren't used for dimming lights, and those dimmers don't
work with DC.

Bye.
Jasen

 

Many Japanese bikes and Harleys have the permanent magnet AC generator
you describe, so the regulator has to deal with the full output current.

The BMW has an ordinary looking automotive alternator sitting on top
of the engine driven by a multi groove belt. Look at the alternator
on top of any Subaru engine and you will see what it looks like. In
fact, the two cylinder engine looks like the front two cylinders of
the Subaru engine. The brushes connect the excitation current from
the regulator (solid state, inside the alternator, in the case of the
alternator) to the wound rotor through a pair of slip rings, just like
in most modern automotive alternators. It is rated 35 amps at idle,
50 amps maximum.

My wife's Suzuki alternator is a permanent magnet, crank shaft mounted
type like you describe, and it has a big, external, heat sink mounted
regulator, that rectifies and SCR phase controls the output to the
electrical system. It is designed such that the bike's electrical
system just about uses all the current it produces at speed, and a bi
less than the bike uses at idle. If this is similar to the Triumph in
question, then, at idle, at least, the vest is bound to sag the
battery when it comes on.

 

Haven't seen your original post, but wonder where the take off point for
your vest is - eg if it and the lights were on a common wire, then you
might be getting a voltage drop across that feeder.

Perhaps as an experiment you could try attaching the vest directly to your
battery instead of where it is now, (couple of battery clips or such) and
see if the problem persists.

David

 

Better yet, as close to the alternator output as possible. that,
after all is where the current comes from.

 

That is my plan to try it on the battery directly. It came with its own
battery clips, but I figured it would be easier to plug in to the power
outlet of course.

 

I dont have any problems with the Triumph nor any pain (except from
riding it too much and too fast). You are perhaps thinking of the old
Lucas stuff. Long and gone.

This machine is superb compared to similar machines out there.
Everything works fine, including running lights, car horns, headlights.
Even the jacket works fine at full power (always on). The problem is
the low tech system Gerbing uses (on/off every second to control the
temperature). 7A is a lot of power to draw on and off constantly
without a momentary brownout.

Anyway, the generator is rated at 27Amps. I dont think I am using all
that.

 

When I rode a motorbike in the UK all I had was a couple of extra pairs of
trousers and some gloves! My helmet was a WW2 tank hat with holes all over
it!

R

 

You have my sympathy. Electric heat is lovely on a bike in winter. I
ride all winter in the state of Virginia, except when there is snow on
the roads (and sometimes I get caught on that).