Today's Message Index:
----------------------
1. 06:56 AM - Re: Re: Switched voltage generator (Robert L. Nuckolls, III)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Switched voltage generator |
At 08:57 PM 6/14/2022, you wrote:
>
>Buy a type "J" thermocouple and attach it to the voltage regulator.
>https://www.omega.com/en-us/temperature-measurement/temperature-surface-sensors/wt/p/WTJ-6-60
>I attached a thermocouple using a regulator mounting bolt.
>Monitor the thermocouple temperature somehow. I connected mine to
>the Dynon D-180 in my plane.
>Go flying and monitor the regulator temperature with a heavy load,
>then a medium load, and then a very light load.
>If the temperature goes up with the load, the regulator is a switching type.
A cogent observation.
I would like to suggest a refinement of terms for the
rectifier/regulators common to permanent magnet
alternator installations. Early in this thread, a
writer expressed some confusion arising from his
search for sources on 'switching regulators' . . .
seems those little bits of plastic with a few connections
coming out of them were not applicable to managing
the energy available from an PM alternator . . .
He's right. In the broader world of electron herding,
SWITCHMODE regulators describe a class of devices common
to electronic energy management devices found in virtually
all consumer products. Things like the little 'wall warts'
that quick-charge our mobile phones up to sine-wave, DC to
AC inverters that might manage thousand of watts . . .
and everything in between. They are the core technology
of step-up, step-down converters and power suplies in our
computers with 'switching' frequencies on the order
of tens of thousands of Hz and higher.
In the PM alternator world, the smallest devices first
showed up in mini-bikes and garden tractors over 40
years ago. The simplest regulators took advantage of
a common design for small alternators that rendered
them impervious to damage to to 'dead shorting' of the
output windings. So the easiest regulator designs
would literally short out or SHUNT excess energy
when a battery was fully charged.
This produces a situation where the alternator is
essentially loaded to full capacity 100% of the time
with the regulator preventing battery overcharge
(or bus over voltage) by turning unneeded energy
into heat . . . both the alternator and regulator
needed design features that tolerated what in
other situations might be considered severe or
even catastrophic overload.
As magnet technology improved and electrical
demands on small machines grew, larger alternators
were developed . . . many configured with 3-phase
windings. Tossing off excess energy with a SHUNT
style rectifier/regulator became rather undesirable
from an efficiency and performance standpoint.
SERIES type regulators were crafted that controlled
excess energy by disconnecting the alternator from
the system during some portion of the AC output
waveform. This produced a situation where as demands
for engine driven energy went down (battery charged,
system load minimal), alternator and regulator
temperatures went DOWN.
Obviously, the generation of heat is directly
related to efficiency so the optimal design
works to minimize waste heat in both machine
and electronics.
Getting back to the core premise of this thread,
the Revmaster engine has a profound design flaw
in the alternator stator which promotes the
burning of windings.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|