Today's Message Index:
----------------------
1. 05:54 AM - Re: Pull-up resistors (Robert L. Nuckolls, III)
2. 06:24 AM - Re: is battery filter or dead weight? (Eric M. Jones)
3. 10:45 AM - Pulse Wave Modulation Dimmers (Jared Yates)
4. 11:41 AM - Re: Pulse Wave Modulation Dimmers ()
5. 12:35 PM - Re: Pulse Wave Modulation Dimmers (Tim Andres)
6. 12:47 PM - Re: Pulse Wave Modulation Dimmers (Robert L. Nuckolls, III)
7. 02:18 PM - Re: Re: is battery filter or dead weight? (Robert L. Nuckolls, III)
8. 04:01 PM - Z-14 Dual Battery, dual alternator. Wire sizing, educate me please. (Terry Mortimore)
9. 07:44 PM - Switch circuitry/function terminology (Andy Hawes)
10. 08:05 PM - Is over-voltage protection recommended for small alternator? (user9253)
11. 08:10 PM - Re: Switch circuitry/function terminology (B Tomm)
12. 10:59 PM - VM1000 backlighting dimming (DEAN PSIROPOULOS)
Message 1
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| Subject: | Re: Pull-up resistors |
At 02:26 AM 1/5/2011, you wrote:
I'm connecting a GNS430w to a pair of GRT MFD's. GRT calls for 10k
ohm pull up resistors to be used on 4 of the interconnects between
the MFD's and the Garmin, these resistors are fed with 12VDC and
"T" 'd into the
harness. http://www.grtavionics.com/File/Wiring%20Diagrams/WD-1007-01.pdf
All this equipment provides for multiple feed paths, and I have fed
all 3 from the E-Bus and my Aux bus. I have read that the Garmin will
be damaged if these pull ups are not used.
I kind of doubt this. Some function may not
behave as intended without a resistor but
I don't believe there is risk of damage to
any particular piece of equipment. These
are signal/control wires with VERY low currents
and no potential for destructive fault
currents.
So to prevent this in the case of power from the AUX only I built a
little pull up network using on a DB25 for a "Home" (Thanks Bob) and
fed it from both bus's (E & AUX). Each bus has a 1N4004 diode
installed prior to feeding the 4 resistors to prevent the bus's from
back feeding. Still with me?
OK so I check it out when done with my Ohmmeter and discover that
instead of 10K ohms I have 326K ohms. All but 10K of it of course is
from the Diodes. I knew the Diodes had a forward voltage drop, but
didn't realize it was this much.
You cannot "measure" the resistance of a diode
with an ohmmeter. Wire per the diagram. No
diodes necessary.
Bob . . .
Message 2
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| Subject: | Re: is battery filter or dead weight? |
The 1 Farad cap I mentioned is pitifully small (Hell, it shows my age that I was
impressed). Here is a 3000F (-0/+20%!) Cap:
maxwell.interconnectnet.com/ultracapacitors/datasheets/DATASHEET_K2_SERIES_1015370.pdf
On Ebay a guy is selling five cases of these (2.7V) 15 per case, for $775/case
OBO. You'd need 5-6 of these to make a proper cell. (In series total capacitance
is 1/(n/C), but you'd still get 500 F at 14V or so)
A few years ago the caps were used more for starting purposes, now they are advertised
more for "energy saving" applications, like stop-start engines, and providing
a boost when starting hybrid cars from a standstill.
See also: maxwell.com/products/ultracapacitors/applications/cold_starting.aspx
--------
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=325653#325653
Message 3
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| Subject: | Pulse Wave Modulation Dimmers |
Earlier someone on the list asked about using these as LED dimmers:
http://www.aircraftspruce.com/catalog/elpages/pwmDimmer.php
Just to follow up, did anyone ever install them and have anything good
or bad to say about them? I noticed that some very similar looking
units are available here:
http://www.allelectronics.com/make-a-store/item/DMR-9/12VDC-18W-PWM-DIMMER/SPEED-CONTROL/1.html
and
http://www.allelectronics.com/make-a-store/item/DMR-10/DUAL-12-VDC-18W-PWM-DIMMER/SPEED-CONTROL/1.html
for a lower price. As Bob said before, it's cheap enough to buy and
try, (even cheaper now), but I thought I'd check first just in case.
Message 4
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| Subject: | Pulse Wave Modulation Dimmers |
Jared,
I use one of these for my panel LED lights. It works ok. Occasionally
the lights blink on/off when the switch is completely off. Also, the
backing on the switch does not grip the panel well which tends to allow
it to spin in the hole.
It modulates the light perfectly and doesn't jump, spark or crackle when
adjusting. If you have LED lights you want to dim, you need one of these
(or a similar cousin). As indicated in the pictures it is easy to hook
up.
Glenn E. Long
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jared
Yates
Sent: Wednesday, January 05, 2011 1:39 PM
Subject: AeroElectric-List: Pulse Wave Modulation Dimmers
<email@jaredyates.com>
Earlier someone on the list asked about using these as LED dimmers:
http://www.aircraftspruce.com/catalog/elpages/pwmDimmer.php
Just to follow up, did anyone ever install them and have anything good
or bad to say about them? I noticed that some very similar looking
units are available here:
http://www.allelectronics.com/make-a-store/item/DMR-9/12VDC-18W-PWM-DIMM
ER/SPEED-CONTROL/1.html
and
http://www.allelectronics.com/make-a-store/item/DMR-10/DUAL-12-VDC-18W-P
WM-DIMMER/SPEED-CONTROL/1.html
for a lower price. As Bob said before, it's cheap enough to buy and
try, (even cheaper now), but I thought I'd check first just in case.
Message 5
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| Subject: | Re: Pulse Wave Modulation Dimmers |
On 1/5/2011 10:39 AM, Jared Yates wrote:
> --> AeroElectric-List message posted by: Jared Yates<email@jaredyates.com>
>
> Earlier someone on the list asked about using these as LED dimmers:
>
I used one, the first one was bad out of the box, I didn't discover it
until several months had passed but ACS replaced it after some
"discussions".
One thing though, I'm told PWM will not dim most avionics.
Tim Andres
>
>
Message 6
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| Subject: | Re: Pulse Wave Modulation Dimmers |
At 01:39 PM 1/5/2011, you wrote:
>
>Earlier someone on the list asked about using these as LED dimmers:
>
>http://www.aircraftspruce.com/catalog/elpages/pwmDimmer.php
>
>Just to follow up, did anyone ever install them and have anything good
>or bad to say about them? I noticed that some very similar looking
>units are available here:
>
>http://www.allelectronics.com/make-a-store/item/DMR-9/12VDC-18W-PWM-DIMMER/SPEED-CONTROL/1.html
>and
>http://www.allelectronics.com/make-a-store/item/DMR-10/DUAL-12-VDC-18W-PWM-DIMMER/SPEED-CONTROL/1.html
>
>for a lower price. As Bob said before, it's cheap enough to buy and
>try, (even cheaper now), but I thought I'd check first just in case.
They will function as advertised. The only caveat goes
to the method for bringing wires onto and off the board.
Emacs!
We discussed the "twist-n-squash" terminal boards
a few years back when Greg featured them on the BMA power
distribution board described on page 41 of
http://www.aeroelectric.com/articles/richter/response_1.pdf
Emacs!
This tecnology for bringing wires off of etched circuit
board argues with the idea of gas-tight connections
favored with immediately adjacent insulation support
discussed in . . .
http://www.aeroelectric.com/articles/terminal.pdf
The technology for these dimmers is pretty simple. Here's
on example of a duty cycle controller suitable
for their LED or incandescent lamps.
Emacs!
A dimmer of this genere could be crafted
with some really solid termination technology
(d-sub, fast-on, etc. etc). Bill of materials
is about $10.
Bob . . .
Message 7
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| Subject: | Re: is battery filter or dead weight? |
At 09:21 AM 1/5/2011, you wrote:
The 1 Farad cap I mentioned is pitifully small (Hell, it shows my age
that I was impressed). Here is a 3000F (-0/+20%!) Cap:
maxwell.interconnectnet.com/ultracapacitors/datasheets/DATASHEET_K2_SERIES_1015370.pdf
Okay, that's a whole new paradigm.
http://www.greencar.com/articles/ultrabattery-combines-battery-supercapacitor-power.php
http://www.technologyreview.com/biztech/18086/
On Ebay a guy is selling five cases of these (2.7V) 15 per case, for
$775/case OBO. You'd need 5-6 of these to make a proper cell. (In
series total capacitance is 1/(n/C), but you'd still get 500 F at 14V or so)
A few years ago the caps were used more for starting purposes, now
they are advertised more for "energy saving" applications, like
stop-start engines, and providing a boost when starting hybrid cars
from a standstill.
Ultracaps been proposed and even advertised for a host
of "new and improved" performance . . . but compared
to what product and for what purpose?
See also: maxwell.com/products/ultracapacitors/applications/cold_starting.aspx
I think it was Mallory that proposed a capacitor
replacement for a lead-acid battery a few years ago
for cranking over the road truck engines. I think
I saw some catalog sheets on product. Maxwell is offering
catalog items with interesting specs . . .
http://www.aeroelectric.com/Mfgr_Data/Capacitors-UltraCaps/Maxwell_BMOD-Series_Ultracaps.pdf
These or similar products may very well be the
solution to engine cranking design goals. Right
now, an OBAM airplane using a $75, 17 a.h. lead
acid battery can plan to support a 4 a load for
3 hours when new, 2.4 hours at end of life. 2.4
hours at 11 volts average and 4 amps is 380KJ of
standby energy.
A capacitor being discharged from 14 to 10.5 volts
delivers 47 Joules/Farad. The equivalent storage
for a lead-acid replacement is something on the
order of 8000 Farads or 16 of the Maxwell modules
connected in parallel for about 800 cubic inches.
Methinks 16 of these critters is larger and a lot
more expensive than the 17 a.h. battery.
I worked lead-acid battery project for HBC a couple
years ago that proposed to used lead-plated carbon
fibers . . . MUCH lighter. Thinner plates with really
good performance numbers. That product turned
out to be made mostly of smoke, mirrors, and computer
models that 'neglected' a few important variables.
I have no doubt that somebody will replace or even
augment the SVLA battery somewhere sometime. If a sense
of history serves us well, it will be years after
Honda, Kia or Chrysler puts a few millions of
consumer road-miles on them before they become
an economic practicality for the OBAM aircraft.
I don't expect to live to see it . . . but I'd be
tickled pink to be proven wrong.
Bob . . .
Message 8
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| Subject: | Z-14 Dual Battery, dual alternator. Wire sizing, educate |
me please.
Hi Gang:
I"m about to start the installation of the Z-14 system into my RV-6A. I've
absorbed and understand most of the drawing, but one thing confuses me and
that is the size of the wire running to the Starter.
>From the starter to the starter contactor shows a 2 AWG wire, the wire from
the starter contactor to the main battery contactor is shown as a 4 AWG
wire.
The wire from the Cross-feed contactor to the terminal on the main battery
contactor is shown as 2 AWG. The wire running from the Aux battery to the
one side of the Cross-feed contactor is shown as a 4 AWG.
I can understand 4 AWG wire running from the two batteries to their
respective contactors, but I would think that from the point where the two
batteries join forces they should be 2 AWG wire? I don't understand why the
size of wire jumps from 4 up to 2 and then back down again to run to the
starter contactor?
Can someone educate me please?
Thanks in advance,
Terry.
Terry Mortimore
426 McNabb Street Apt#4
Sault Ste Marie, Ontario
P6B 1Z3
Message 9
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| Subject: | Switch circuitry/function terminology |
Wondering if anyone can give me an overview of toggle switch functionality
related to how the switching function is described.
What switching function would you want for a toggle switch in order to have
two separate circuits controlled INDEPENDENTLY, where you can leave one
circuit on while controlling another?
i.e. -- ON -- OFF -- ON: With this switching function, wouldn't you
have to turn off one side in order to activate the other?
Would a relay be necessary to do this, again, with ONE toggle switch?
I believe what I am after is a double pole (two separate circuits), double
throw (two contact directions) switch, but I am confused as to how one
toggle switch can control both on/off for two separate circuits?
Thank you!
Andy
Message 10
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| Subject: | Is over-voltage protection recommended for small alternator? |
Some builders think that they do not need over-voltage protection because their
EFIS will warn of high voltage and they can shut off the master or add additional
load to reduce the voltage, especially if the alternator is a small PM alternator.
In effect, they plan to regulate the voltage manually.
I believe it is better to have automatic over-voltage protection because it will
take the pilot too long to react. By then expensive avionics could be damaged.
A small PM alternator can put out too high of a voltage if lightly loaded
and the regulator fails. I recommend some type of over-voltage protection.
What do others think?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=325754#325754
Message 11
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| Subject: | Switch circuitry/function terminology |
Andy,
I think what you want is a "progressive" double pole three position switch.
Scroll to the bottom of these links.
http://www.carlingtech.com/products/switches/learn_more.asp?page=switches_ba
sic-circuit-function
Switch function diagrams here, scroll to bottom.
http://www.carlingtech.com/pdf/cirdiagrams.pdf
Of course many manufactures make them. I bought mine at
http://www.bandc.biz/toggleswitch-doublepole.aspx
These are awesome functions and very useful for aircraft. I am employing
several in my RV7A. Have fun.
Bevan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Andy
Hawes
Sent: Wednesday, January 05, 2011 7:40 PM
Subject: AeroElectric-List: Switch circuitry/function terminology
--> <andy717@comcast.net>
Wondering if anyone can give me an overview of toggle switch functionality
related to how the switching function is described.
What switching function would you want for a toggle switch in order to have
two separate circuits controlled INDEPENDENTLY, where you can leave one
circuit on while controlling another?
i.e. -- ON -- OFF -- ON: With this switching function, wouldn't you
have to turn off one side in order to activate the other?
Would a relay be necessary to do this, again, with ONE toggle switch?
I believe what I am after is a double pole (two separate circuits), double
throw (two contact directions) switch, but I am confused as to how one
toggle switch can control both on/off for two separate circuits?
Thank you!
Andy
Message 12
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| Subject: | VM1000 backlighting dimming |
A question for both Bob and VM1000 owners with the original (black and
white) LCD display:
Situation: I bought the VM1000 system in 2002 but it wasn't operating in
the airplane until 2008. Flying at dusk I notice that the LCD screen
backlighting works but is not bright enough for me to read the display. The
VM1000 manual says the backlighting power is generated by a 0-80 volt AC
inverter inside the VM1000 CPU box and that the inverter output is
proportional to the DC voltage on the dimming input of the CPU connector.
The manual notes that full brightness will be achieved when close to full
battery voltage is input at the dimming connection. Unfortunately it does
NOT say exactly what value of "close to full battery voltage" is required to
get full brightness.
Bob:
I installed a B&C dimmer (DIM 5-14, half amp output max) on the dimming
input of the VM1000 CPU connector. I got to talking with someone about the
output of this device and a question came up as to exactly how close to bus
voltage is output when the control is set to full output. I can't recall, is
the output pulse width modulated, and if so, does the device ever achieve a
full bus level output voltage? Or, if the LM317 is a linear device, is the
DIM 5-14 circuit designed to achieve a full bus level output voltage when
the pot is set to full output? If not what percentage of full bus voltage
can I expect? Also, if the DIM 5-14 output is too low can I remove the
circuit board from the equation and just connect the potentiometer (that is
supplied with the DIM 5-14) between the Essential bus and the VM1000 dimming
input to achieve full voltage at the VM1000 dimming input (in other words,
is the potentiometer robust enough for this task or will I burn it up)? Any
other words of wisdom you care to pass on?
VM1000 Owners:
Have any of you come up against this issue? What did you do to solve it?
Were you using a B&C dimmer or some other device? Being the original
designer/owner of Vision Microsystems sold the company and disappeared, does
anyone know exactly what percent of battery voltage is required to get full
output on the display? What failure modes does the display backlighting
system exhibit (i.e. if the backlight works is it just insufficient dimming
input voltage that makes the brightness too low or does the inverter circuit
have failure modes that set the backlighting to some intermediate
brightness)? If so what are those failure modes and can the circuit be
repaired to restore output to full brightness.
Thanks everyone
Dean Psiropoulos
RV-6A N197DM
2 years of flying fun
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