[HomeBrew] Re: RE: Homebrew Equiv. of Ameritron ALS-500M?

[DavidE Benedict]

bcromwell at michonline.net writes:
>** Please do NOT cross-post messages when posting to HOMEBREW **
>
>Hi David,
>
>Automotive alternators do not have the output voltage determined by
>windings but by the drive applied to the rotor windings through the
>regulator...up to the physical capacity limits of the hardware used.
>Automotive alternators have been used for welding and for powering tools
>like electric drill motors for years. If you want to consider a 50 volt
>application you can buy a 'replacement' alternator designed for use with
>an external regulator and then make your own regulator.
>
>I would not recommend driving very far on just the battery in any
>electronically controlled, fuel injected car. The auto industry has
>considered a move to 42 volt systems to help with the huge electric load
>in these cars. Maybe they can be convinced to go all the way to 48 volts
>(really 50).
>
>Bill KU8H
>
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Hi Bill, thank you. 
I am answering a number of folks at once here....

Presently I use a diode isolator from SurePower...simple diode and simple
hook-up to help supply my IC-706 MKII-G. (Hope to go to a IC-7000 one day
soon)

I like to home-build, so I will build my mobile amplifier. The transistors
using 30-60 volts are both cheaper and much easier with which to design &
build, and, additionally the power/supply wires can be a much smaller
copper wire, which is cheaper and easier to handle & route. So that's the
big reasons for wanting to use 50 VDC. 
--Too, for some of these same reasons vehicle manufacturers are looking
seriously at going to 36, 42, or 48 Volt batteries and electrical systems
(all of which can be used directly and handily for mobile amp
designs)...I'll be ahead of the curve a bit.

But with the dual voltage scheme which I am thinking of, I would parallel
my 2 batteries for the car's use (for longer carry-thru when they're not
being charged), and use the regulator's 2nd voltage (48-50 VDC) direct to
the amplifier, but buffered by a massive capacitor bank.

--The alternator is slave to the regulator's control, so I'd be switching
both the regulator's steering voltage and the regulator's DC output
simultaneously when I would transmit. That is, switching away from the
default, the 12 VDC steer and the 12VDC output to the batteries, and over
to 50 VDC steer and outputting the 50 VDC to the amplifier's input
capacitor bank; I might use 4 motorcycle batteries in series instead of
the capacitor bank, but I hope the capacitors will do it alone.

FYI, pulling the guts from the older 80's Subaru alternator I found at the
junkyard is impossible, as it is all both physically/mechanically and
electrically integrated with the innards of the alternator. But I did
manage to electrically isolate all the stuff, and, with much difficulty,
brought out the individual wires for my crude R&D efforts. 

David B.
W7DBH