load / resistance spec for aux / 12v circuit

[schwankl]

Can anyone share the 12v circuit spec (or findings) for a redshift mxr? probably for ip67 rating they have some load / resistance band for operation.
I can power baja 4-led system at 11 or 37w fine, but when I try to use an incandescent (from a dot certified polisport mmx) which only uses 30w the circuit gets shutoff. Its fine using the 5w running-light incandescent - just doesnt like the load/resistance when a 30w main incandescent is used. Tested the harness with a 12v lead-acid battery and verified its only using 30w.

 

[datadog]

I don't know the specs, but the deciding factor is inrush current. The ACM detects inrush overcurrent and shuts off the circuit. Google inrush limiting there's a few different methods.

 

[schwankl]

Thanks @datadog

Any overall power guidance / max wattage of this 12v aux circuit ? I did have the circuit fused at 3amp, but sounds like the ACM is quicker/smarter for inrush current.

Would a fuse ever make a difference / safer circuit? Or the ACM is robust in keeping the circuit within bounds?

Do you have a paypal account so I can buy you lunch/beers or something?

 

[Philip]

but when I try to use an incandescent (from a dot certified polisport mmx) which only uses 30w the circuit gets shutoff.

And does the circuit then restore itself back to normal operation after you key cycle the bike? So is it safe to fiddle with the AUX connector without having to go to a dealer to reset anything or clear fault codes?

Yes, I am also curious if a fuse may be needed.

 

[schwankl]

Ya it resets with key cycle

 

[bluefxstc]

I don't know the specs, but the deciding factor is inrush current. The ACM detects inrush overcurrent and shuts off the circuit. Google inrush limiting there's a few different methods.

I wonder if you could use a inrush current limiter to limit the inrush current and keep the circuit happy while still using the circuit for something other than the light bulb?

 

[Gertech]

@schwankl have you had any luck playing with the 12v circuit? Curious as I'm either going to use it to power some lights or build a stand-alone harness with a separate battery for lights. Thanks!

 

[schwankl]

It powers the Baja 37watt led lights fine ... they are just not dot certified ... was thinking about using my exr light to pass inspection then put the baja back on. Winter has hit here and riding snowboard now. Adding an inrush limiting curcuit has not been a priority or blocker.

 

[schwankl]

All the other lights, turn signals and horn are powered fine by the 12v circuit - it was just that incandescent polisport pos

 

[privateer703]

Do the baja lights have the ability to select an individual LED? By that I'm wondering if I could use the baja lights with a hi/lo beam switch. I'm looking at making a complete stand alone harness for my MXR and would like to use the baja lights but need some type of hi/lo switch to pass inspection. The guy who does my inspection won't care that they're super bright LED's, so long as I can show a low and high beam and I really don't want to buy some crappy halogen light just to pass inspection.

 

[schwankl]

Ya the Bajas do hi/lo - 11watts lo, 37 hi. These are the ones ULTIMATE Kit - 2014-16 KTM

 

[rayivers]

so long as I can show a low and high beam

Jumpering the light on/off switch with a resistor or series diode string would turn it into a hi/lo beam switch (larger-value resistor or more diodes = less lo-beam brightness).

 

[Gertech]

Sweet, thanks for that @schwankl

 

[schwankl]

I verified a simple ntc themistor (3amp and 5amp) works to limit inrush current for the incandescent dot certified headlight. 4pcs NTC 47D-15 Inrush Current Limiter Thermistor NTC 3Amp 47 Ohm (CL-80) | eBay ... I am only using this to pass safety inspection for a street legal mxr then will put back on the bajas. The themistor does get too hot to touch, but i guess thats normal and this is only temporary. Using a capacitor to minimize the voltage drop / current spike might be another way, I took the simple route as it will be used only for a few hours. Still would be nice to get the specs on the 12v aux circuit to know the limits ... that still top secret / under nda?

 

[Motophyllic]

By any chance did you consider trying a PTC thermistor? I’m considering trying that with a bypass. Not my area of expertise, looking for help here.

 

[schwankl]

it will not work, you need to use ntc. ptc is opposite of ntc - it will effectively turn off/open circuit via high resistance when it gets hot after a few sec. https://www.ametherm.com/wp-content/uploads/2015/10/resistance-temperature-curve-graph.png

 

[Motophyllic]

I am trying to put an inline switch on my headlight so I can turn it off. I worry about the heat burning something. Do you know of any other ways to limit the inrush current that won’t get so hot?

 

[bluefxstc]

I am trying to put an inline switch on my headlight so I can turn it off. I worry about the heat burning something. Do you know of any other ways to limit the inrush current that won’t get so hot?

Unless you have a bad switch you shouldn't generate any heat, you are turning power off. No current, no heat. From my experience you may lose your tail light if you turn it off, but that should come back on when you cycle the key.

 

[Redwolf]

I think the goal is to be able to switch the lights on and off and back on without cycling the key switch...

 

[Motophyllic]

It’ll probably be 50/50 with the light off/on. For the time the light is turned on, I worry about generating heat. I’ve spent so many hours trying to figure this out. I know someone out must have done this before.