Five blown lights -- one night; regulator stuffed?

[davereid]

Your alternator produces AC, which is passed through a diode pack (Rectifier) to convert it to a series of half-wave pulses.

Battery charging.
As all these pulses are positive going when compared to the ground of the frame, they are suitable for charging a battery.

DC power.
This "rectified AC" as it is called is not really DC though, as it goes from a value of zero, to its peak value (about 19 volts) and back to zero again, many times a second. (The exact rate depends on your engine rpm.)

The battery and capacitor.
If you have a battery installed, the battery will tend to charge during the period where the rectified ac wave is greater in voltage than the battery. The battery will discharge, but maintain system voltage when the rectified ac wave is at a lower value than the battery voltage. But the battery resists going much above its nominal voltage, and helps stabilise the system voltage, normally at about 70% of the peak voltage.

A capacitor on the other hand tends to charge to the peak of the applied rectified ac waveform. So bikes running a battery free system tend to run a bit high in voltage, and bulbs particularly become sensitive to vibration and like to fail at switch on, or at high rpm.

Your regulator, and the average life of your bulbs will improve if you can find a bit of extra load to add to the bike.

An extra 12-20 watts would help the problem go away. This is where the idea of the wire wound resistor comes from. Even increasing the wattage of the bulb you use for your headlight would help.

[smudge]

Didn't mean to upset you, apologies if I did. I don't know the history behind it all, just trying to help a fellow motorcyclist...

One thing I can tell you is that with these type of systems if it isn't all 'balanced' it will suffer from over voltage problems, as I said before I'm a sparky who has done this stuff to bikes before. You are getting some good advice here from the other guys so I'll butt out.

[xwhatsit]

Didn't mean to upset you, apologies if I did. I don't know the history behind it all, just trying to help a fellow motorcyclist...

One thing I can tell you is that with these type of systems if it isn't all 'balanced' it will suffer from over voltage problems, as I said before I'm a sparky who has done this stuff to bikes before. You are getting some good advice here from the other guys so I'll butt out.

Sorry mate, I misinterpreted what you were saying and over-reacted. I need to drink more coffee Oh well, at least I used up my weekly mindless rant.

@davereid: Cheers for that, very enlightening. I realised the DC was really a cut sine-wave (^^^^^^^), but I didn't understand the relevance for this when comparing batteries and capacitors. I'm sure I can find something that will sink 20W in my box of bits. I'm still leaning towards a `real voltage regulator' as it seems a more elegant solution, but that will probably come with its own set of difficulties.

Thanks guys.