Isn’t that something. I quit reading after the switch.

I think I’m pro VW now.

 

https://www.google.com/search?q=hea...=utf-8&oe=utf-8#q=headlight+modulator+circuit

thanks for the link, shortbus

 

Welcome to AAC!
1) Assuming the common terminal of the twin-filament light is presently grounded, can you isolate it from ground? This would enable an easily-obtainable N-channel MOSFET to be used for switching both filaments.
2) Are you prepared to accept a reduced life for the light? Filaments don't take kindly to being repeatedly switched on and off.
3) Be aware that flash rates of about 7Hz can trigger epileptic seizures in susceptible people.

Hi Alec:
Thanks for the thoughtful reply. Yes, the ground wire to the female plug is easily interrupted. Also I have acquired a new aftermarket headlight that has two amber "half-halos" built into it, seperately wired. These can be use to mirror/augment t/signals, or can be left on as running lights (which is what I am gonna do). It came with a halogen bulb, but that's a pretty serious watt-sucker and these old bikes don't generate a lot of juice from the simple 3pole stator assembly. So, I am thinking of installing an LED headlight bulb. I tested it on the bench and it seems like a winner, but actually function on the road remains to be seen. Are there any differences when using an LED regarding your ground-interrupt idea? Thanks
s

 

The flash rate and intensity for a modulator in the US as listed here are:

• The rate of modulation shall be 240 ±40 cycles per minute.

• The headlamp shall be operated at maximum power for 50 to 70 percent of each cycle.

• The lowest intensity at any test point shall be not less than 17 percent of the maximum intensity measured at the same point.

Thanks for the reference. I wonder where webbikeworld got this info. Gonna go fish about in the DOT guide... if I can find one on line. In any case, then I just need to figure out what sort of device I can rig up that will follow these regulations... even with these parameters it still seems like I oughta be able to DImyself as opposed to plunking $70+

 

They got it from the US Code as they referenced it on their webpage.

 

Having regard to posts 14 and 19, it looks like controlling the ground connection is a non-starter .

 

Having regard to posts 14 and 19, it looks like controlling the ground connection is a non-starter .

That may be an official "requirement" but no one is going to examine your circuit to make sure it does not switch the ground, if you are building it only for your own use.
As it appears to be some bureaucratic requirement, I wouldn't worry about it.

 

yes. it seems they don't want your headlight to go black if an added-on component fails... Which isn't inherently a bad idea. One of the companies making this plug/play component prices it at $109. It's made in the USA, which I wholly support. I don't wanna "steal" their idea and market products... I don't want to buy a 30% cheaper chinese copy of their idea. I would love to make my own component just because I like that sort of thing (and do that readily with non-electronic components for which, as is I am sure already obvious to you experts, I have no training). Anyway, they describe the product that would fit my bike as follows. Note that they have it hard-wired to the highbeam circuit only - so WORST CASE/total fault tolerance would be that it fails and leaves you with full/normal low beam functionality. Downside is being hella annoying to other drivers by flashing brights at them. That said, i often run with brights on during daylight hours unless I am following someone in traffic and don't wanna fry their eyes via the mirror. I also switch to low beams when stopped at long lights etc. SO given that, what would be wrong with a (perhaps simpler?) ground-interrupt modulator for the high beam line only, for which I can splice an inline cutout switch manually or attach it to a remote mounted daylight sensor:

P115W-S unit is totally self-contained. There are no hidden boxes or switches. There are no wires to cut or splice.

P115W-S unit is designed for 3-pin H4 or a Japanese H7 2-pin style headlamps. It's 1.25" (32mm) round, and requires NO ADDITIONAL SPACE after it's plugged on the back of the bulb.

pathBlazer circuit modulates the hi-beam current - from 100% ON to about 17% OFF. This is accomplished by using a p-channel MOSFET, which is inherently safe. The MOSFET is designed to fail in the ON state. For additional safety, the circuits DO NOT utilize the lo-beam whatsoever!

MAX power rating is 115 watts. DO NOT EXCEED!

P115W-S comes with a detachable daylight sensor, which simply plugs into the pathBlazer. The daylight sensor functions as a switch; it stops modulation when it cannot see enough daylight. Since the internal circuitry is controlled by a microprocessor, it allows for customizable features.

Programmable Daylight Sensor

If you turn the high beam on and then turn the ignition on three times quickly, the sequence is interpreted as an active command to change the sensitivity.

Current software version v.823A allows 8 linear steps between the high and low end.

The daylight sensor has a low frequency filter to avoid false triggering. Please note that florescent lamps may not trigger the sensor - it needs constant incandescent light.

pathBlazer uses a soft-switching technique. It throttles the current flow through the bulb filament, so that there's no "thermal shock" due to a sudden inrush of current, which can damage the bulb filament or shorten its life considerably. This is far superior than maintaining a small voltage!

Select hi-beam to modulate - as long as there's sufficient daylight. If you enter a tunnel or if it gets dark, it will stop the modulation of the hi-beam and stay ON steady. Select lo-beam to end modulation.

You have complete control.

 

They got it from the US Code as they referenced it on their webpage.

Yes, sorry. You're right JoeJester... I missed that reading small text on my phone with old eyes.

 

Isn’t that something. I quit reading after the switch.

I think I’m pro VW now.

Hi Br-549. I am curious as to what you meant here? thanks

 

Howdy Steve,

That was my feeble attempt at sarcasm. I couldn’t believe those regs on modulating a headlight.

I can just imagine trying to cope with regs involving a combustion process.

It’s no wonder that company's like VW, and individuals cheat on regulations.

Or hire lawyers to argue definitions when caught and fined.

It’s such a parasitic waste.

 

Howdy Steve,

That was my feeble attempt at sarcasm. I couldn’t believe those regs on modulating a headlight.

I can just imagine trying to cope with regs involving a combustion process.

It’s no wonder that company's like VW, and individuals cheat on regulations.

Or hire lawyers to argue definitions when caught and fined.

It’s such a parasitic waste.

Well... maybe. This is anecdotal but I think it is also a good template for what happens when it all "works." I lived in LA when I was a little kid... the air was brown and I was sick with asthma at least half the year. We moved to Northern California and suddenly little Steve was pretty good at sports. I came back to LA to go to UCLA when the air was still brown, and was sick half the year again. There were smog alerts a few times a year and I remember (literally) being unable to climb the hill from campus to dorm because I was sucking wind like a 90 year old emphysema patient. I transferred to UCBerkeley, and suddenly, I was hiking, running, playing soccer and baseball. Hell, I even joined the boxing club. In 1992 I moved back to LA and you know what? The brown air had turned blue. It's even better today. It has been many years since there was a smog alert... and several at least since there has been any kind of smog warning at all on the west side of town (near UCLA) where I live. This amazing transformation didn't happen because industry (auto in particular) volunteered to change things. The market didn't force it to happen. There are some regs that are ludicrous, for sure. There are all sorts of victimless crimes that shouldn't be crimes, for example. But it was clear that short-sighted corps were poisoning us because it helped their bottomlines, and the pushback against them that has directly resulted in citizens suffering less is, imho, kind of a good use of our gov't.

 

....................
I can just imagine trying to cope with regs involving a combustion process.

It’s no wonder that company's like VW, and individuals cheat on regulations.

Or hire lawyers to argue definitions when caught and fined.

It’s such a parasitic waste.

The waste would be having no regulations, as Steve noted.

VW and others don't cheat because the regulations are too complex, they cheat because they figure out how to game the regulations to increase their bottom line, even if it means polluting the environment.
The complexity wasn't the problem, it's that they weren't complex enough to prevent VW from cheating.
I'll take government regulations to improve the environment over letting corporate greed control it anytime.

 

what would be wrong with a (perhaps simpler?) ground-interrupt modulator for the high beam line only

The complication is that the ground terminal of the sealed beam unit is common to both filaments. The existing wiring switches 12V (6V?) selectively to the non-grounded terminals, so a rewire would be needed to 'turn the unit upside down' (electrically, not physically).

 

The complication is that the ground terminal of the sealed beam unit is common to both filaments. The existing wiring switches 12V (6V?) selectively to the non-grounded terminals, so a rewire would be needed to 'turn the unit upside down' (electrically, not physically).

Don't see why that's a problem.
If you interrupt the ground, only the high beam will be modulated if only the high beam is on.
For night driving the modulator needs to be shorted (continuously on) anyway, which is legally required for a modulator.
On my cycle I modulate the low beam. The flickering can still be readily seen but it doesn't have the annoying glare that a high beam has (I want the oncoming cars to notice me, not be angry at me).

 

Do you feel safer now? That's the excuse for this intrusion.

10th Amendment is ignored.

Oh, good. We have the constitution involved. Drivers all over the country are feeling better already. Please start talking about guns and abortion next - that will certainly help the OP with his circuit.

 

Don't see why that's a problem.
If you interrupt the ground, only the high beam will be modulated if only the high beam is on.

True. Brain not in gear .