Today's Message Index:
----------------------
1. 06:23 AM - Re: Over voltage with Z13/8 (Robert L. Nuckolls, III)
2. 09:12 AM - Re: com antenna problem (=?iso-8859-1?Q?Th=E9o_Celis?=)
3. 10:53 AM - Jabiru 3300 Schematic (Terry Phillips)
4. 11:55 AM - Re: Jabiru 3300 Schematic (Robert L. Nuckolls, III)
5. 12:32 PM - Re: com antenna problem (Robert L. Nuckolls, III)
6. 12:51 PM - Re: Jabiru 3300 Schematic (Terry Phillips)
7. 05:43 PM - 20 Amp Solid State Relay usage (Tony Gibson)
8. 08:49 PM - Re: 20 Amp Solid State Relay usage (Richard T. Schaefer)
9. 10:52 PM - Good deals on AMP T-head tools (Robert L. Nuckolls, III)
10. 10:54 PM - PIDG .25" Fast-On terminals (Robert L. Nuckolls, III)
Message 1
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Subject: | Re: Over voltage with Z13/8 |
At 11:26 PM 12/10/2007 -0500, you wrote:
>
>I expect that typically Z13/8 is normally run in flight with the SD-8
>alternator off.
yes
>If both alternators were on, I expect the current generated would be
>dependent on which regulator is set to the slightly lower voltage. So
>possibly the SD-8 would be at full output, with the main alternator
>picking up the slack. Although undesirable, I expect it would not
>actually damage anything. The opposite would be ideal really, with
>the SD-8 producing current only if the main alternator was not.
correct
>My real question though is:
>If an overvoltage spike occurs, would both overvoltage modules take
>both alternators offline ?
OV conditions are not properly described as spikes.
The term spike is used to describe fast risetime, short
duration, low energy events such as the transient that
develops in the magnetic field collapse within a
contactor coil.
>I expect yes, and I do not see any way around it. To do otherwise,
>would risk too long of a high voltage condition.
An OV condition is generated by loss of regulation in
a power generating device such as an alternator or
generator. In a OV runaway mode, the device goes into
a max effort attempt to push the bus voltage up.
If the bus is lightly loaded and there is no battery
present, then the resulting scenario can lift the
bus to some amazing and certainly damaging voltage
levels. See:
http://aeroelectric.com/articles/When_is_110V_not_Over_Voltage.pdf
IF a battery is present and in good shape, the
battery will willingly attempt to soak up as
much of the excess energy as its physics will
allow. When a 60A alternator is launches
for the moon, the battery will willingly
accept 60+ amps of excess output but at a
slightly elevated voltage. For example, some
tests I ran and plotted a couple of years ago
showed that a 17 a.h. battery with a 20A
over charge rose fairly fast (10 mS or so)
to 16 volts and then more slowly taking perhaps
500 milliseconds to rise to 17 volts.
Obviously, the greater the overcharge current,
the greater will be rate of rise. I'm still
planning on doing the full scale runaway experiments
when I get my alternator drive stand running.
In the mean time, know that a runaway condition
from ANY size alternator is not a heart-stopping
event as long as the battery is there to mitigate
the results. An OV protection system for a 14
volt system is generally set for 16.2 to 16.5
volts. Between the battery's willingness to slow
the rate-of-rise and the OV protection module's
ability to sense and bring the event to heel in
tens of milliseconds takes all the bite out
of what could be a serious failure.
The voltage plot of an OV even is a long duration,
very high energy surge which is not a concern
in the well maintained system (good battery)
and artfully crafted OV protection system.
>Should the maintenance switch option for the E-Mags that was
>previously depicted in deleted Z33 be added to Z13/8 ?
No. With the configuration shown, the Emag
products are in the maintenance mode every time
the bus is hot but the control switch is in
the NON-running or OFF condition.
Bob . . .
Message 2
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Subject: | Re: com antenna problem |
Connections on the ammeter: 4 studs (and 2 wires for the internal lt):
pwr, gnd, 2 from the shunt.
I reread the instructions (with diagram) and they refer to AC4313.13...
They mention the use of 18awg for all wires - exc the light.
Nothing is said about meter sensitivity or the use of shielded
wire.
I should mention that the checks were done in the workshop where
ceiling and floor contain rebars and the door is aluminum.
Reception of nearby Brussels app is excellent.
The tip-up canopy was removed for easy access.
Best regards,
Tho.
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
Sent: Saturday, December 08, 2007 11:29 PM
Subject: Re: AeroElectric-List: com antenna problem
> <nuckolls.bob@cox.net>
>
> At 06:11 PM 12/7/2007 +0100, you wrote:
>
>><theo.celis@skynet.be>
>>
>>Thank you Bob, Ralph & Bob F.,
>>
>>A few tests confirmed exactly what you said, Bob.
>>Just moving my body while txmitting resulted in large
>>needle deflections.
>>As somebody mentioned, the RV is full metal.
>>The ammeter is one that Vans sells : a 40A shunt model, -40/0/+40 scale.
>>The coil is housed in an aluminum cylinder, inside the plastic instrument.
>>There is a PCB with some resistors, transistors etc.
>>The instrument itself is located in a centre console under the main instr
>>panel.
>>The voltmeters we used to play with during elec lessons were far less
>>complicated...
>>We measured 7mV over the shunt with all avionics turned on and when
>>pressing the PTT it shot up to 12mV.
>>My friend brought a handheld RX and our tx tested fine.
>>
>>Thanks a million for yr help.
>
> Transistors are to radio frequency energy as
> mobile homes are to tornados. It is all too
> common in the OBAM aviation community that the
> designers of electro-whizzies have not considered
> the potential effects of radio frequency energy
> coming from a perfectly normal comm transmitter
> and antenna installation.
>
> I looked at Van's listing for the -40/0/+40
> instrument and it's not clear that this is
> an "electronically enhanced" instrument. Other
> than two wires from the shunt to the instrument,
> are there any other wires that need connection
> to say ship's power?
>
> By the way, the amount of RF found in the cockpit
> of an RV (due to proximity to a properly installed
> comm antenna system) is no greater than what is
> expected in light aircraft. It's an exceedingly
> rare situation where an observed interference
> between the comm transmitter and some piece of
> panel mounted equipment is the fault of the
> installer or serendipitous combination of conditions.
> It's nearly always a shortcoming of the victim
> system's design.
>
> Do the installation instructions for this insrument
> mention anything an installer should do to forestall
> such interference?
>
> Bob . . .
>
>
>
Message 3
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Subject: | Jabiru 3300 Schematic |
On another forum, I found a reference to schematic Z21A for A/C with the Jabiru
3300 engine. I found Z21A.pdf on aeroelectric.com, but I cannot find a Z21A.dwg.
Can anyone help me find the .dwg file?
Thanks.
--------
Terry Phillips
Corvallis, MT
ttp44<at>rkymtn.net
Zenith 601XL/Jab 3300 slow build kit - Rudder done--finally; working on the stab
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=151700#151700
Message 4
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Subject: | Re: Jabiru 3300 Schematic |
At 10:51 AM 12/11/2007 -0800, you wrote:
>
>On another forum, I found a reference to schematic Z21A for A/C with the
>Jabiru 3300 engine. I found Z21A.pdf on aeroelectric.com, but I cannot
>find a Z21A.dwg. Can anyone help me find the .dwg file?
http://www.aeroelectric.com/PPS/ACAD_Architecture_Dwgs/Z21A.dwg
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 5
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Subject: | Re: com antenna problem |
At 06:10 PM 12/11/2007 +0100, you wrote:
><theo.celis@skynet.be>
>
>
>Connections on the ammeter: 4 studs (and 2 wires for the internal lt):
>pwr, gnd, 2 from the shunt.
>I reread the instructions (with diagram) and they refer to AC4313.13...
>They mention the use of 18awg for all wires - exc the light.
>Nothing is said about meter sensitivity or the use of shielded
>wire.
And it shouldn't. What you describe is the ordinary
signal-powered instrument designed to be used with
the conventional ammeter shunt. I can think of no
reason for this device to be sensitive to radio
frequency energy.
>I should mention that the checks were done in the workshop where
>ceiling and floor contain rebars and the door is aluminum.
>Reception of nearby Brussels app is excellent.
>The tip-up canopy was removed for easy access.
None of this is relevant. Without launching a
$time$ consuming research task to see why this
instrument seems to be affected, we're probably
not going to learn of the root cause and remedy.
Know that there are a number of similarly affected
displays on type certificated aircraft wherein the
crew are instructed to "disregard the perturbations
observed while transmitting."
It would be interesting to know why and perhaps
institute a fix . . . but it's not going to add
value to your finished product in proportion to
the cost of knowing what the fix is.
Bob . . .
Message 6
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Subject: | Re: Jabiru 3300 Schematic |
Thanks, Bob.
Do not archive
--------
Terry Phillips
Corvallis, MT
ttp44<at>rkymtn.net
Zenith 601XL/Jab 3300 slow build kit - Rudder done--finally; working on the stab
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=151729#151729
Message 7
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Subject: | 20 Amp Solid State Relay usage |
Hi everyone, if applicable I'd also like to use this relay for switching an electric
heater... a 35A forced air infra-red quartz unit from Aircraft Spruce.
It says the contacts of the VF4-65F11 are rated for 40A?
http://www.chiptech.com/secondary/manu-prod_pdf/P/Potter&Brumfield.pdf
Since it's offered with quick connect terminals I'm assuming fast-ons would be
OK to use here? Thanx for any help,
Tony Gibson
Winnipeg, Manitoba
From: "Scott R. Shook" <sshook@cox.net>
Subject: RE: AeroElectric-List: 20 Amp Solid State Relay usage
I too am using the AML34 and AML24 switches in my panel. Pacific Coast
Avionics recommended using the Potter Brumfield VF4-65F11 relays for
higher
loads.
Any thoughts on these relays Bob? Are they reliable enough?
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
---------------------------------
Never miss a thing. Make Yahoo your homepage.
Message 8
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Subject: | Re: 20 Amp Solid State Relay usage |
> Hi everyone, if applicable I'd also like to use this relay for switching
> an electric heater... a 35A forced air infra-red quartz unit from Aircraft
> Spruce.
>
> It says the contacts of the VF4-65F11 are rated for 40A?
> http://www.chiptech.com/secondary/manu-prod_pdf/P/Potter&Brumfield.pdf
>
> Since it's offered with quick connect terminals I'm assuming fast-ons
> would be OK to use here? Thanx for any help,
>
> Tony Gibson
> Winnipeg, Manitoba
>
> From: "Scott R. Shook" <sshook@cox.net>
> Subject: RE: AeroElectric-List: 20 Amp Solid State Relay usage
>
>
> I too am using the AML34 and AML24 switches in my panel. Pacific Coast
> Avionics recommended using the Potter Brumfield VF4-65F11 relays for
> higher
> loads.
>
> Any thoughts on these relays Bob? Are they reliable enough?
>
>
> Scott R. Shook
> RV-7A (Building)
> N696JS (Reserved)
>
>
> ---------------------------------
> Never miss a thing. Make Yahoo your homepage.
That type of heater will likely be classified as a resistive load so you
should not have a problem if the relay was set to switch 40A loads.
Message 9
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Subject: | Good deals on AMP T-head tools |
Check out these buy-it-now prices on
the king of PIDG terminal service tools.
I'm all fixed up with tools or I'd buy them.
http://ebay.com
Item 150193891967
Item 150193892277
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 10
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Subject: | PIDG .25" Fast-On terminals |
Also see this ebay offering for PIDG
fast-on terminals. AMP dwg:
http://tinyurl.com/2ws3ln
Ebay item:
120096613362
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
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