after market brakelights flashing too fast

[skip]

Hey I have a question for ya. My wife got me a a pair of streetfx elctro brake pods http://www.streetfxseries.com/brake-electropods.html for my bike.(2004 kawi zzr1200) they are little one inch rectangle pods that have 8 leds in each and flash when you apply your brake lights. Here is my problem . at 10 or 11 volts that i have at the brake light with the motor off they flash perfect. as soon as I start the motor and even at the same 11.8 volts ( I had everything on, heated vest, gloves, highbeams gps, satellite radio and brake lights) it now flashes way too fast, almost like a twinkle.. as soon as I shut the motor off it flashes normal. I called the manufacturer and they sent me a "noise filter" and when i put that inline it slowed the flashing down a tiny amount, but nowhere near enough . any idea of what i could put in line to slow the flashing down while the motor is running? ..........thanks .......skip

 

[Killer2600]

How good is your ground?

 

[tom203]

Head to Radio shack and get a pair of diodes ( 1 amp, 50 PIV ) and experiment. Put in series with wiring to your pod lights (observe forward polarity)- each diode will drop voltage by about .6 volts. One might be enough, but three might be required. But might flash real slow or not at all when engine ain't running.

 

[skip]

How good is your ground?

I grounded them right to the battery after using a frame ground the first time. same results

 

[skip]

Head to Radio shack and get a pair of diodes ( 1 amp, 50 PIV ) and experiment. Put in series with wiring to your pod lights (observe forward polarity)- each diode will drop voltage by about .6 volts. One might be enough, but three might be required. But might flash real slow or not at all when engine ain't running.

checke on their website found 1 amp diodes but could not find 50 PIV? whats it stand for?

 

[posplayr]

The device is suspect, but if it is good at 10.5V then maybe a simple regulator to keep the input voltage to the "pods" woudl work even when you rev the engine and the voltage goes up.

This is a simple device using also using a diode but it wll regulate to the specific voltage.

http://en.wikipedia.org/wiki/Zener_diode

BZX79C10
BZX79C11

pick something like the BZX79C10 or 11 (rated at 500mWatts)
and a 30 ohm (use at least a 1 Watt resistor)

I played with the values for voltage ranges between 10-15 volts and you will have to be careful with both the diode or the resistor getting hot.

using a 10V zener and 30 ohm resistor there should be enough current to the two flashers by 12.5 volts

@15.5V P_Diode is 0.8Watts and P_resistor is 1 Watt
@16.0V P_diode is 1.0Watts and P_resistor is 1.2 watts

if you make one device for each pod then the Power values drop in 1/2 and the referenced devices might just work.

http://www.fairchildsemi.com/ds/BZ/BZX79C5V6.pdf

 

[850GT_Rider]

Seems like a lot of work for devices that should be designed to work at a nominal 12-13v.

I'd say they're defective.....

 

[posplayr]

Seems like a lot of work for devices that should be designed to work at a nominal 12-13v.

I'd say they're defective.....

It is a gift from the wife.......

 

[tom203]

Well, putting two diodes in series just caused the lights to dim with no effect on flashing- science can be cruel. This gizmo must be picking up on charging pulses and getting upset. Does this bike have a car type alternator or just a permanent magnet rotor/stator system? In the good old days we used to put noise filters on power feed to radios to eliminate static from the charging system. You would think the Chinese might have tested it, but maybe this unit is defective.

 

[skip]

Well, putting two diodes in series just caused the lights to dim with no effect on flashing- science can be cruel. This gizmo must be picking up on charging pulses and getting upset. Does this bike have a car type alternator or just a permanent magnet rotor/stator system? In the good old days we used to put noise filters on power feed to radios to eliminate static from the charging system. You would think the Chinese might have tested it, but maybe this unit is defective.

its called a generator when you look up the parts for it, but it kinda looks like an alternator. the manufacturer sent me a tiny noise filter to slow the flashing but it did not help, if it slowed it at all it was a tiny bit. I saw radio shack had rectifiers that worked in the 12 volt range but now I am not convinced its a voltage problem. Today i am going to take my battery jump box and hook up the flashing brake pods to it directly. I know that can be charged up to 13.8 . if it flashes normal at 13.8 from the battery jump box then I have to rule voltage out as an issue and concentrate on interference or defective parts

 

[tom203]

Hey, I like your thinking! you could even add a D battery in series with the jump starter to boost voltage into the 15 volt range to test.

 

[skip]

its not a voltage issue, I had13.5 with the charger on the battery and they flashed normal. I un hooked the charger, started the bike, and at 12.7 they flash crazy fast . I am stumped

 

[UncleMike]

Never thought I'd hear Skip complain about something being TOO fast ...

 

[skip]

Never thought I'd hear Skip complain about something being TOO fast ...

so true

 

[UncleMike]

so true

If it's too fast, you're too bald ... I mean old!

 

[tom203]

My conclusion is.... this unit is defective- they said it would work on 11 to 15 volts.
Here's what we used to do for radios- the transformer (actually a choke) blocks the AC component and the capacitor sends it to ground
http://radioproshop.com/filters/cf2.htm

A more up to date version would be like this

http://radioproshop.com/filters/ns2.htm

But the lights should have been designed for this problem. get another

 

[posplayr]

The problems seems to be a sensitivity to voltage noise. The R/R's tend to create deep negative spikes (1-2 volts) at the 3 phase power rate.

The attached filter is actually a simple two stage device. The first diode/cap pair does a real good job at reducing the negative spikes. Depending upon the size of the cap you use and the current draw from the load you could be able to reduce negative spikes to less than 0.25 volts.

The zener shunt second stage provides active suppression of noise from what is left over because the zener adjusts it's current to maintain the output voltage at the 10V or 11V rating of the device. It is not a perfect regulation so you will still see some variation coming out.

Note the only reason I'm recommending this shunt zener regulator is because you only have an LED load of less than 100 mAmps. Anything requiring more current could use a 3 terminal regulator to supply up to 500 mAamps or more.

This simple device will be smaller and more effective at filtering the power than any choke or other linear filter

 

[posplayr]

My conclusion is.... this unit is defective- they said it would work on 11 to 15 volts.
Here's what we used to do for radios- the transformer (actually a choke) blocks the AC component and the capacitor sends it to ground
http://radioproshop.com/filters/cf2.htm

A more up to date version would be like this

http://radioproshop.com/filters/ns2.htm

But the lights should have been designed for this problem. get another

IIRC, the noise spikes are at RPM/10 Hz (18 pole stator)
So 5000 rpm ==> 500 Hz. This is not RF noise it is very low frequency.

 

[tom203]

IIRC, the noise spikes are at RPM/10 Hz (18 pole stator)
So 5000 rpm ==> 500 Hz. This is not RF noise it is very low frequency.

Yes, you are correct, but it was an example of filtering out the ripple AC current inherent in a charging system- most stuff would ignore it, but this flasher is responding to it.

 

[posplayr]

Yes, you are correct, but it was an example of filtering out the ripple AC current inherent in a charging system- most stuff would ignore it, but this flasher is responding to it.

The point I was making was that the frequencies are so low that the physical size of any linear componenets (e.f. a choke or r-c filter) that would provide significant filtering would be very large. Instead, the non-linear devices (i.e. diode, zener) are effective at these low frequencies.