Any EEs Here? School me on Relays?

[OzzyRob]

Yep.

Std headlight has 2 filaments think of two globes in one, brake\tail lights are similar. Say 45W for low and 60W for high. The power is switched between the two. They shouldn't be on at the same time.

Just in case anyone hasn't mentioned it if you use a dimmer the excess power will get converted into heat and will need to be ventilated\cooled properly.

And make sure you have the correct angles for the hi & Lo beams. Cos it can be annoying to almost dangerous to oncoming drivers if they aren't. After having done quite a few night runs between Syd & Brisbane and Syd & Melbourne (1000k trip one way) a badly adjusted oncoming headlight is a make the beast with two backsen pregnant dog.

[Dry Martini]

If the alternator was is like the type used in cars or some touring motorcycles (field winding rather than a permanent magnet rotor) where the regulator controls output by field current) you would be correct.  In the case of our Ducatis and most motorcycles tuxicle and Speeddog are correct, excess current turns to heat.  Too much heat makes smoke, and we all remember what happens when the smoke gets out:

Regardless of whether the current is supplied to various loads, or it is shed as heat,the regulator and rectifier diodes will still see the same amount of current. Where excess heat becomes a problem is poor design and placement of the reg/rect to get rid of that heat. Yes, under the seat is not the best place for one.

[tuxicle]

I believe on the classic Monsters, anyway, that the low beam is shut off when the high beam is engaged. One way around this is to use a diode on the high beam signal. This would make things work properly even when using the passing switch.



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I showed the "control" line with a dashed line to indicate that you can use the high beam signal to control the LED light brightness through some other means (perhaps a relay, etc), the diode will "isolate" the line from the voltage that appears at the LED lamp input when the H4 connector's LO BEAM signal is active.

I indicated an 1N4007, this is a cheap 1A diode that should be available at any Radio Shack or local component vendor. Other variants change the last digit (1N4004, for example), for this application they're all equivalent. You could also use a higher current diode like a 1N5401, these are rated for up to 3A average current. The diode should be connected as indicated, the "arrow" points to the side of the diode with a silver band. Use some heat-shrink tubing to wrap up all the connections and you should be done.

I believe Kui (aka He Man) also wrote about this in his HID tutorial.

[tuxicle]

Regardless of whether the current is supplied to various loads, or it is shed as heat,the regulator and rectifier diodes will still see the same amount of current. Where excess heat becomes a problem is poor design and placement of the reg/rect to get rid of that heat. Yes, under the seat is not the best place for one.

While placement is an issue, the way the shunt regulators work is they short-circuit the stator for part of the cycle. By adjusting how much of the cycle they short out, they achieve voltage regulation. The OEM regulators use SCRs to short out the stator, while the Shindengen units use MOSFETs. SCRs have a higher "ON" resistance than MOSFETs, so for the same short circuit current, they generate more heat.

[xsephirot]

And make sure you have the correct angles for the hi & Lo beams. Cos it can be annoying to almost dangerous to oncoming drivers if they aren't. After having done quite a few night runs between Syd & Brisbane and Syd & Melbourne (1000k trip one way) a badly adjusted oncoming headlight is a make the beast with two backsen pregnant dog.

Yeah, true that.

Regardless of whether the current is supplied to various loads, or it is shed as heat,the regulator and rectifier diodes will still see the same amount of current. Where excess heat becomes a problem is poor design and placement of the reg/rect to get rid of that heat. Yes, under the seat is not the best place for one.

Heh.. I have my mosfet regulator under my seat. I couldn't think of any better place to mount it that would get enough air on it.

I believe on the classic Monsters, anyway, that the low beam is shut off when the high beam is engaged. One way around this is to use a diode on the high beam signal. This would make things work properly even when using the passing switch.



Uploaded with ImageShack.us


I showed the "control" line with a dashed line to indicate that you can use the high beam signal to control the LED light brightness through some other means (perhaps a relay, etc), the diode will "isolate" the line from the voltage that appears at the LED lamp input when the H4 connector's LO BEAM signal is active.

I indicated an 1N4007, this is a cheap 1A diode that should be available at any Radio Shack or local component vendor. Other variants change the last digit (1N4004, for example), for this application they're all equivalent. You could also use a higher current diode like a 1N5401, these are rated for up to 3A average current. The diode should be connected as indicated, the "arrow" points to the side of the diode with a silver band. Use some heat-shrink tubing to wrap up all the connections and you should be done.

I believe Kui (aka He Man) also wrote about this in his HID tutorial.

Thank you so much for that diagram Jim! If I apply it to my application I believe the input goes to the control (dimmer relay) and then to the lo beam. So if I add a diode to the high beam, then wouldn't the hi beam be also dimmed (same output as lo beam)?

Or if I reversed the diagram and had the diode on the lo beam along with the control? Because the LED naturally is powered to 100% and the dimmer is there just to dim (waste energy/heat)

[tuxicle]

OK, that last diagram was not complete, that's why the "control" signal was marked with a dashed line. Here's something closer to what you'd actually end up with:



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Note that I've marked the relay terminals with generic names, automotive relay data sheets will tell you which terminals are coil (polarity usually does not matter, I used "+" and "-" since the CAD program I drew the figure with won't let me give two terminals the same name). The "NO" terminal is "normally open", which gets connected to the "COM" (common) terminal when the coil has 12V applied to it. This should be wired across the dimmer unit's switch. You'd probably have to crack it open to get access to the switch and solder in some wires. Then, wire the dimmer as recommended by the manufacturer. As shown, the yellow/green control wire from the LED light should go to the dimmer. The remaining should go to the battery, or some other source of +12V.

HTH.

[xsephirot]

So I just got the wiring harness and lights today. The harness is setup completely different than the picture with diodes and different what I imagined.

I suppose their way will work but I have a question:

The H4 low beam is going to power my dimmer but I also want to use the "parking" wires to also power the dimmer when I turn my key to 'park'. If I connect the positive of the parking wire and the low beam h4 into a butt slice that goes into the dimmer will there be any issues? I'm just assuming say if the bike is on and running that the positive current from the h4 won't affect and go in reverse (if that makes any sense) into the parking positive.

Or do I need a diode on both positives for the low and parking?

*edit* after much much more googling, i suppose my question should be: is the power from the h4 and the parking lights AC or DC? I'm sure it's XOR?

[tuxicle]

The main headlights and parking lights look like there shouldn't be a problem connecting them together. When the bike's running and the low-beam is turned on, the voltage at the H4 bulb's low beam filament should be +12, same as that at the parking bulb. Connecting them together should not cause any problems.

Also, all the loads on the bike are DC.