Today's Message Index:
----------------------
1. 04:33 AM - source for relay (Chris Hukill)
2. 08:01 AM - Re: source for relay (Robert L. Nuckolls, III)
3. 08:49 AM - Re: Re: Power Opti-Miser (Robert L. Nuckolls, III)
4. 10:58 AM - Re: Power Opti-Miser (Eric M. Jones)
5. 01:47 PM - Re: Re: Power Opti-Miser (Ed Anderson)
6. 03:16 PM - Re: Re: Power Opti-Miser (ray)
7. 07:52 PM - Re: Re: Power Opti-Miser (Jay Hyde)
8. 08:12 PM - Re: Re: Power Opti-Miser (Richard E. Tasker)
Message 1
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| Subject: | source for relay |
I'm back on the list after a couple of years building hiatus, and now am
wiring my RV10. I need a source for a high quality, low holding current,
20 amp or more rated, continuous duty relay. I need one for the avionics
master, and one for the alternate ebus source. I've checked the
archives, and couldn't find anything. Does anyone have a source for
these?
Chris Hukill
Message 2
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| Subject: | Re: source for relay |
At 06:12 AM 12/10/2009, you wrote:
>I'm back on the list after a couple of years building hiatus, and
>now am wiring my RV10. I need a source for a high quality, low
>holding current, 20 amp or more rated, continuous duty relay. I need
>one for the avionics master, and one for the alternate ebus source.
>I've checked the archives, and couldn't find anything. Does anyone
>have a source for these?
>Chris Hukill
Not sure what your criteria is for "low holding current".
The physics of relay construction are rather limiting when
trading off pull in voltage vs. holding current vs. meeting
specs over a wide temperature range.
For years we've recommended plastic, automotive relays
having fast-on tabs that are not unlike this . . .
http://aeroelectric.com/Pictures/Relays/Plastic_Relay_2.jpg
http://aeroelectric.com/Pictures/Relays/s704-1l.jpg
These are inexpensive and available from dozens of
suppliers.
However, given that electro-mechanical relays are the
LEAST reliable of all your power control devices,
they should be used in situations where loss of function
is either no big deal -OR- backed up with a Plan-B.
Before folks run out and start ripping relays out
of their airplanes, understand that the statement above
is comparative. Certainly our cars are fitted with
buckets full of relays. Nonetheless, most of us are
unaware of their presence because we're very seldom
faced with a need to replace one. But those are CARS
and not AIRPLANES. The rule of thumb for factoring
a relay into an airborne system design calls for due
consideration and mitigation of failure mode effects.
Bob . . .
Message 3
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| Subject: | re: Power Opti-Miser |
At 11:20 PM 12/9/2009, you wrote:
>Bob,
>I can't thank you enough for all the help you have given us. You
>have likely saved me (and no telling how many others) $1000 by fully
>explaining how this thing works and why we would be wasting our
>money. It just looked too good to be true and I could only think of
>one place to get an answer and you came through again!
>
What you're experiencing is the beneficial fall-out for
what scientists call perpetual skepticism. There is NO
idea, new, old, obscure or widely practiced that should be
shielded from questions. Good ideas offered by honorable people
welcome the opportunity to share. Some folks must resist
questions about bad ideas when the answers shine a bright
light on their ignorance/dishonesty. It's the
difference between being a teacher and a huckster.
For the limited times I subject myself to what
spews from contemporary television broadcasting,
I sometimes amuse myself with a fantasy about writing
to the advertisers of many products and services to
ask some questions. Obviously a waste of time. We KNOW
it's unlikely that any answer at all will be gratifying.
Their sales depends on how much folks DON'T know about
the product or service being offered. I would be simply
dismissed as a nuisance.
>Thanks! Bob.
No problem. Now YOU are armed with some concepts and
facts that qualify you to teach what you've learned.
Use it in good heath for the benefit of those who are
important to you.
Bob . . .
Message 4
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| Subject: | Re: Power Opti-Miser |
Yes, indeed it is possible and even money saving to use such a device. I was initially
puzzled how little technical stuff there was, but then I remembered that
NASA worked on, published and licensed everything in the early 1980s. (Patent
+ 20 years...hey!).
Power-Miser technology was a big deal then: Google "Power Miser NASA" and you will
get lots of info. Or search the old NASA archives or patents around 1980.
The way the thing works is er...ah...well...I think it might change the power factor
to match the load. I did a lot of work on power factor correction and I
can assure you saving money is possible. This works only on inductive loads as
far as I remember.
The product is real, and so is the money savings. How long it takes to pay off
the device varies.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones@charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=277034#277034
Message 5
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| Subject: | Re: Power Opti-Miser |
Just a wag, but from long ago, I seem to recall that an electric motor
(inductor) had the voltage lagging the current by 90 deg phase (or perhaps
it was the current lagging the voltage), in any case, you get the maximum
efficiency out of the juice if the voltage and current are in phase. I
can't recall the details, but seems I recall a capacitor was used to shift
the phase of the current to be in phase with the voltage.
Or perhaps something I dreamed as a youth {:>)
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Eric M.
Jones
Sent: Thursday, December 10, 2009 1:55 PM
Subject: AeroElectric-List: Re: Power Opti-Miser
<emjones@charter.net>
Yes, indeed it is possible and even money saving to use such a device. I was
initially puzzled how little technical stuff there was, but then I
remembered that NASA worked on, published and licensed everything in the
early 1980s. (Patent + 20 years...hey!).
Power-Miser technology was a big deal then: Google "Power Miser NASA" and
you will get lots of info. Or search the old NASA archives or patents around
1980.
The way the thing works is er...ah...well...I think it might change the
power factor to match the load. I did a lot of work on power factor
correction and I can assure you saving money is possible. This works only on
inductive loads as far as I remember.
The product is real, and so is the money savings. How long it takes to pay
off the device varies.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones@charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=277034#277034
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Message 6
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| Subject: | Re: re: Power Opti-Miser |
Bob,
I find that yelling the questions at the TV offers some satisfaction,
and is quicker than writing, but I'm typically stared at by those around me.
Raymond Julian
Kettle River, MN.
do not archive
Robert L. Nuckolls, III wrote:
> At 11:20 PM 12/9/2009, you wrote:
>> Bob,
>> I cant thank you enough for all the help you have given us. You have
>> likely saved me (and no telling how many others) $1000 by fully
>> explaining how this thing works and why we would be wasting our
>> money. It just looked too good to be true and I could only think of
>> one place to get an answer and you came through again!
>>
>
> What you're experiencing is the beneficial fall-out for
> what scientists call perpetual skepticism. There is NO
> idea, new, old, obscure or widely practiced that should be
> shielded from questions. Good ideas offered by honorable people
> welcome the opportunity to share. Some folks must resist
> questions about bad ideas when the answers shine a bright
> light on their ignorance/dishonesty. It's the
> difference between being a teacher and a huckster.
>
> For the limited times I subject myself to what
> spews from contemporary television broadcasting,
> I sometimes amuse myself with a fantasy about writing
> to the advertisers of many products and services to
> ask some questions. Obviously a waste of time. We KNOW
> it's unlikely that any answer at all will be gratifying.
> Their sales depends on how much folks DON'T know about
> the product or service being offered. I would be simply
> dismissed as a nuisance.
>
>> Thanks! Bob.
>
> No problem. Now YOU are armed with some concepts and
> facts that qualify you to teach what you've learned.
> Use it in good heath for the benefit of those who are
> important to you.
>
> Bob . . .
>
> *
>
>
> *
Message 7
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| Subject: | Re: Power Opti-Miser |
You are on the right track Ed, an inductive load, such as a motor, will
produce a lagging current (the current phase angle lags, or is 'behind', the
voltage phase angle). An ideal inductor will produce a lag angle of 90deg,
and an ideal capacitor will produce a lead angle of 90deg, hence they cancel
one another (should you have an ideal inductor and capacitor of the same
size connected to your system) and the current is thus in phase with the
voltage.
The angle between the voltage and current is called the phase relation angle
and is also termed 'phi' from the greek symbol used in diagrams to
illustrate it. The Cosine of phi is termed the power factor. The smaller
the angle the more cos phi tends to 1, which is what you want. Reactive
power, which is also called the 'non-real' component of power is the
bug-bear of AC systems and one tries to minimise this. Reactive power is
calculated by considering the sine of phi, viz: Q= VxIxsin phi where Q is
reactive power. Active power, P, is calculated by using P= VxIxcos phi.
That as background; in AC systems most loads are inductive but the 'phi'
angle is not 90deg (lagging), but more like 30deg. Similarly, capacitors
are also not perfect and do not have a 90deg leading angle.
When one attempts power factor correction it only really works well when
your load, and load angle (phi) is constant; then you can match capacitors
to the lagging load angle and get it as close to zero as possible. However,
in the real world loads are seldom constant; their actual load varies,
voltage conditions vary from the supplier, and also from other nearby loads
as they switch in and out. Thus a fixed size capacitor cannot keep the load
angle to a constant minimum. Some power factor correction systems switch
various capacitor sizes in and out but they are normally too slow to react
accurately. The cost of maintenance on capacitors and such switching
systems usually means that they seldom save the user costs in the long run;
a combination of the installation costs, maintenance and poor real savings
(as a result of how power is generally costed).
Newer systems employ a special transformer that can be 'driven' in and out
of saturation (which then controls its lagging power angle) and these,
together with switched capacitors, appear to be able to offer real savings
in the long term. Their capital cost ensures that they are only used in
fairly large installations- say 400kVA and larger.
Another power saving device that one wants to steer clear of is something
called the 'Magniwork' generator. It promises substantial power savings and
a search of the web will get many hits that appear to verify the claim. A
colleague of mine paid the $60 for the plans and asked me to evaluate them.
They appeared impressive at first glance but it soon became apparent that it
was absolute nonsense and that the author was working on the 'bullshit
baffles brains' principle.
At least the capacitors are based on real engineering knowledge...
Jay
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ed
Anderson
Sent: 10 December 2009 11:45 PM
Subject: RE: AeroElectric-List: Re: Power Opti-Miser
<eanderson@carolina.rr.com>
Just a wag, but from long ago, I seem to recall that an electric motor
(inductor) had the voltage lagging the current by 90 deg phase (or perhaps
it was the current lagging the voltage), in any case, you get the maximum
efficiency out of the juice if the voltage and current are in phase. I
can't recall the details, but seems I recall a capacitor was used to shift
the phase of the current to be in phase with the voltage.
Or perhaps something I dreamed as a youth {:>)
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Eric M.
Jones
Sent: Thursday, December 10, 2009 1:55 PM
Subject: AeroElectric-List: Re: Power Opti-Miser
<emjones@charter.net>
Yes, indeed it is possible and even money saving to use such a device. I was
initially puzzled how little technical stuff there was, but then I
remembered that NASA worked on, published and licensed everything in the
early 1980s. (Patent + 20 years...hey!).
Power-Miser technology was a big deal then: Google "Power Miser NASA" and
you will get lots of info. Or search the old NASA archives or patents around
1980.
The way the thing works is er...ah...well...I think it might change the
power factor to match the load. I did a lot of work on power factor
correction and I can assure you saving money is possible. This works only on
inductive loads as far as I remember.
The product is real, and so is the money savings. How long it takes to pay
off the device varies.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones@charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=277034#277034
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database 3267 (20080714) __________
The message was checked by ESET NOD32 Antivirus.
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 3267 (20080714) __________
The message was checked by ESET NOD32 Antivirus.
Message 8
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| Subject: | Re: re: Power Opti-Miser |
Yeah, my wife sometimes thinks I'm nuts when I start explaining how
stupid some of the claims are and how what they are saying is often
impossible. Fortunately, I don't watch much TV so she hasn't decided to
commit me yet.
Dick Tasker
ray wrote:
>
> Bob,
>
> I find that yelling the questions at the TV offers some satisfaction,
> and is quicker than writing, but I'm typically stared at by those
> around me.
>
> Raymond Julian
> Kettle River, MN.
> do not archive
>
> Robert L. Nuckolls, III wrote:
>> At 11:20 PM 12/9/2009, you wrote:
>>> Bob,
>>> I cant thank you enough for all the help you have given us. You
>>> have likely saved me (and no telling how many others) $1000 by fully
>>> explaining how this thing works and why we would be wasting our
>>> money. It just looked too good to be true and I could only think of
>>> one place to get an answer and you came through again!
>>>
>>
>> What you're experiencing is the beneficial fall-out for
>> what scientists call perpetual skepticism. There is NO
>> idea, new, old, obscure or widely practiced that should be
>> shielded from questions. Good ideas offered by honorable people
>> welcome the opportunity to share. Some folks must resist
>> questions about bad ideas when the answers shine a bright
>> light on their ignorance/dishonesty. It's the
>> difference between being a teacher and a huckster.
>>
>> For the limited times I subject myself to what
>> spews from contemporary television broadcasting,
>> I sometimes amuse myself with a fantasy about writing
>> to the advertisers of many products and services to
>> ask some questions. Obviously a waste of time. We KNOW
>> it's unlikely that any answer at all will be gratifying.
>> Their sales depends on how much folks DON'T know about
>> the product or service being offered. I would be simply
>> dismissed as a nuisance.
>>
>>> Thanks! Bob.
>>
>> No problem. Now YOU are armed with some concepts and
>> facts that qualify you to teach what you've learned.
>> Use it in good heath for the benefit of those who are
>> important to you.
>>
>> Bob . . .
>>
>> *
>>
>>
>> *
>
>
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