Originally Posted by crypto666
Chris, can you explain the reduction in charging resistance? I don't quite understand that, I thought that was purely a product of the battery's internal resistance?
The only reason I thought it would work, while not being ideal, is that the xrr service manual shows some schematics that are similar; dc and ac system from the same coil. Or so I thought, looking at again there are two coils. However, these wiring diagrams are obviously not of an xrr so who knows what the hell thats all about?
I think in theory you could have an ac light, and still rectify it for a dc system. However, there wouldn't be a need for both ac reg and a reg/rectifier, because only one of the regs is going to be doing its job.
It would be simpler to just go all dc.
The battery is the source, the rectifier is the load (resistance). Anytime you add resistance in parallel (like the second regulator) it lowers total resistance increasing current. This
explains it with a calculator and shows the formula. Type in a few values into R1 & R2 and you'll see the loss of overall resistance, plug that new value into ohms law and you'll see the increase in circuit current I'm describing, it could easily double the current, not good!
I'm not telling the OP not to do it and I might be missing something here but in my expierence why add the complexity and the overhead associated with an extra reg? We want our systems to be as simple as can be and as robust as we can make them. Each componet will add some loss of output to the system by virtue of it's resistance in that circuit. Almost all headlight bulbs that run on AC will run on DC. The final product will end up being more complex, run hotter and have more potential for failure. I seriously doubt the headlight will be any brighter if it does work at all, it's hanging off a circuit in a very inefficient way.
I've worked on my share of MC electrical systems as well as plenty of other electric/electronic sircuits and have yet to see a system that is configured for 2 different voltage types off the same output in this manner. The closest thing I can think of is when they pull more than one tap off a source like a transformer or set of windings. In that situation, the way the windings are configured provides circuit isolation. Doesn't mean the OPs method isn't out there but typically at a min. there is some circuitry or design feature that minimizes ones influence on the other.