Maybe there is a way to make the Ducatti regulator much more reliable.
Going by the schematic on the Contrails website, there is nothing much
special about this regulator.
It is very similar to many other motorcycle regulators that operate without
a field control voltage.
At least it is similar to a regulator I made for my own motorcycle, about 5
years ago.
Similar to what someone explained a few emails ago:
The unit monitors the regulated DC output voltage. If it is too high, it
grounds the alternating current (AC) that is coming direct off the
alternator, until the DC output voltage is in range (probably something less
than about 15 volts). If the load of the aircraft is high, the alternator
voltage (AC) is low hence the DC output is less than 15V and the clamping
device need not fire. Hence, the clamping device (SCR, or the like) will
LAST LONGER with higher aircraft loads.
Then why are people seeing the regulator failing at high loads? Well, it
must be the rectifier diodes that are failing. They are the only high-power
devices that COULD fail, based on the schematic (which isn't drawn
perfectly, but good enough to tell what's happening).
Luckily, both sides of the diodes in the regulator are accessible by the
external terminals of the regulator itself. If one were to take two
high-current diodes (maybe use Schottkey's, which have a much smaller
turn-on voltage..that will almost guarantee complete bypass of the smaller
Ducatti diodes), with their cathodes connected to the 'R' terminal and each
one of the anodes connected to the 'G' terminal on the regulator (one for
each), the internal diodes would either be helped or mostly bypassed, as
long as the turn-on voltage for the power diodes was less than or equal to
the turn-on voltage for the Ducatti's internal diodes. Doesn't hurt to try
it either way..
Alternatively, one could connect the anode of one diode (lets call it diode
#1) to one of the 'G' terminals (on the Regulator) and the cathode to the
'R', while diode #2 anode would be connected to the other 'G', with its
cathode connected to the 'B+' terminal on the Regulator. This should be
do-able, since B+ and R are one and the same, according to the schematic.
Has anyone done this?....or maybe someone can try and report back any
success.
That's the way I see it anyway,
Greg
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