Today's Message Index:
----------------------
1. 06:29 AM - Strobe Noise Low Voltage? (MHerder)
2. 07:36 AM - Re: Trim tab indicator (Eric M. Jones)
3. 07:53 AM - Re: Strobe Noise Low Voltage? (Robert L. Nuckolls, III)
4. 08:18 AM - Re: Strobe Noise Low Voltage? (MHerder)
5. 08:37 AM - Re: Re: Trim tab indicator (Mike Welch)
6. 12:06 PM - Re: Strobe Noise Low Voltage? (edleg)
7. 12:10 PM - Re: Strobe Noise Low Voltage? (MHerder)
8. 01:27 PM - Re: Trim Tab Indicator (Keith Burris)
9. 03:37 PM - Catch diode location (jonlaury)
10. 03:49 PM - Re: Catch diode location (Eric M. Jones)
11. 04:46 PM - Re: Catch diode location (Bob McCallum)
12. 06:06 PM - Re: Catch diode location (jonlaury)
13. 06:44 PM - Re: Re: Strobe Noise Low Voltage? (Neal George)
14. 08:23 PM - Re: Re: Catch diode location (Bob McCallum)
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: | Strobe Noise Low Voltage? |
Can and how if so, low voltage cause strobe noise in your headset?
--------
One Rivet at a Time!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=315816#315816
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Trim tab indicator |
I've posted lots on this subject, and offer a TSCMR (True Servo Controller for
MAC-RAC), which allows you to use a linear or rotary potentiometer or stepped
resistor switch to control the trim box. Even if you don't want one, the details
should interest you:
periheliondesign.com/moreproductsfiles/ServoController%20macrac.pdf
I decided to re-engineer the TSCMR with many additional features but don't currently
sell it. It got complicated. Details on request.
Regarding position indicators, the advantage of using a pot, trim wheel or any
non-pushbutton means of control is knowing where the trim is set. The Ray Allen
trim indicator expects 1.28V MAX voltage. Minimum voltage is raised off zero
a tiny bit, but not enough to prevent transmitter, intercom, etc. noise from
getting into the display.
There are a zillion ways to build higher output LED bar graphs, any you'll probably
have to roll your own with brighter LEDs. The LM3914 is current limited.
Perhaps the easiest approach is drive optoisolators such as 10 of the TLP222G
which then drive whatever LED you want up to 85 mA or so.
Google "Bargraph kit" for many available roll your own kits.
--------
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=315824#315824
Attachments:
http://forums.matronics.com//files/rac_trim_and_trim_indicator_schematics_159.pdf
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Strobe Noise Low Voltage? |
At 08:26 AM 10/15/2010, you wrote:
><michaelherder@beckgroup.com>
>
>Can and how if so, low voltage cause strobe noise in your headset?
Can you explain the background for this question?
Generally speaking, low voltage is not a proximate
cause for changes in noise levels. Under what conditions
of "low voltage" do you perceive a noise that is
not perceptible under conditions of "higher voltage?"
Bob . . .
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Strobe Noise Low Voltage? |
Background:
Headset noise observed with strobe on, Garmin SL40 and Flightcom 403 intercom,
Aeroflash Srobe (By Noise I mean Whine). Contributing factor was certainly strobe
wires too close to radio. I verified this by moving the strobes entirely
away from the radio wires Noise went away Closer together Noise. I then decided,
I wasnt happy with my first attempt at making a harness anyway, so instead
of rerouting the strobe wires, I would reroute the audio wires. I did that
, and the noise went away entirely. To the point that with my eyes closed I
couldnt tell whether or not the strobes were on, with my headset on. THEN I came
out the next day, no noise but as the voltage level decreased Say to 10V,
(nearly dead battery) the strobe noise reappeared, and appear to increase with
decrease in voltage.
So now I have what I would describe as an intermittent problem, that appears to
be varying with my voltage levels. The first thing I will do is obviously charge
the battery to where it should be, but even if it goes away with a charged
battery, Id like too know why such a thing would be occurring.
--------
One Rivet at a Time!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=315836#315836
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Trim tab indicator |
> I've posted lots on this subject=2C and offer a TSCMR (True Servo Control
ler for MAC-RAC> --------
> Eric M. Jones
> www.PerihelionDesign.com
Eric=2C
That is a very nice article and design you've got. Probably more than I
need at this point=2C tho.
From the contributions so far=2C I have an little bar graph indicator com
ing from Allen Fulmer=2C which I
will check out. Next=2C and what seems to hold the most promise=2C is that
circuit Joe Gore supplied using
the LM3914. I suspect that that will be the one I use. It appears to be e
asy enough (for me) to build=2C
and provides exactly what I was after in the first place...a line of 3mm LE
Ds=2C with one lit up to show the
tabs position.
I like the meter Bob offered=2C too=2C but the LED design is my preferred
goal.
Thanks to everyone for their generous input. This list is truly an asset
to the homebuilt enthusiast!!
Mike Welch
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Strobe Noise Low Voltage? |
Normally at 10vdc you don't have an intermittant noise problem.... you have a failed
electrical system. I believe the "normal" low voltage cutoff for a 12v battery
should be 10.5v and anything lower is leading to disaster (literally and
figuratively).
Why would you test your electrical system at 10vdc when that is not a normal operating
parameter... and who cares if there is noise at 10vdc?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=315873#315873
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Strobe Noise Low Voltage? |
I'm not intentionally testing it that low, it's just that I'm not flying and I'm
only running the engine every couple of weeks. I've spent hours upon hours
trying to find my strobe noise issue. In the mean time, I'm realizing that I
haven't charged the battery and all the while my strobes are draining battery.
Last night it just occured to me that my problem might just be related to that.
And, I dont care if there is strobe noise at 10V as long as that is the issue
and not a poor ground or something similar.
--------
One Rivet at a Time!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=315874#315874
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | RE: Trim Tab Indicator |
Bob:
A couple of questions on your miniature meter movements;
How does one change the scale? Is it difficult to get the face plate off?
Would just a piece of paper with the scale you want printed on it be
sufficient for the scale or would you have to use a special paper? I presume
the meter is a 0 to full scale operation. Is there any easy way to make it
a center zero meter such that you could use it for a 30 0 30 ammeter? Also,
I was unable to find the product listing for the price of the miniature
meter on your webpage. How much is the meter?
Thanks in advance.
-- Keith
Bob Nuckolls wrote;
There's another option. We have a quantity of
Tripplet 120 miniature meter movements. This
is the same core we use for the 9007 loadmeter.
These could be offered as trim indicators also
by fitting with scale plates not unlike those
shown here:
http://www.aeroelectric.com/Pictures/Instruments/Trim/Trim_Indicators.pdf
<http://www.aeroelectric.com/Pictures/Instruments/Trim/Trim_Indicators.pdf>
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Catch diode location |
In the attached, I don't understand the pathway for the inductive spike of the
Grnd Pwr contactor to dissipate. I thought that the diode symbol always pointed
to positive.
And where does the catch diode go/orient on the Stby Alt Contactor?
Thank you,
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=315902#315902
Attachments:
http://forums.matronics.com//files/z8_w_sb_alt_gpj_conceptual_rev_b__838.pdf
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Catch diode location |
Or use bidirectional Zeners like you should and don't worry about it.
--------
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=315903#315903
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Catch diode location |
John;
In all cases the "spike catcher" diode goes across the coil just as it does
and is shown on the battery contactor and with that same orientation. The
drawing you've attached has no "spike catcher" on the ground power
contactor. If you wish that feature it would have to be added. The diodes
currently shown are for polarity protection to prevent energizing the
contactor should the connect ground power be reverse polarity, and to allow
the light to indicate polarity.
The direction of the diode symbol depends on what use you are trying to make
of the diode. Its orientation to prevent "reverse flow" may be different
than if its purpose is to provide an alternate path for induced voltages.
You can also use a bidirectional zener as Eric suggests for spike
suppression, but these won't work for directing current flow such as in the
reverse polarity protection circuit. Different purpose, different
characteristics, different functions, different connections. (Sometimes able
to be achieved by the same component however)
Bob McC
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-
> server@matronics.com] On Behalf Of jonlaury
> Sent: Friday, October 15, 2010 6:34 PM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Catch diode location
>
>
> In the attached, I don't understand the pathway for the inductive spike of
the Grnd
> Pwr contactor to dissipate. I thought that the diode symbol always pointed
to
> positive.
>
> And where does the catch diode go/orient on the Stby Alt Contactor?
>
> Thank you,
> John
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=315902#315902
>
>
>
>
> Attachments:
>
>
http://forums.matronics.com//files/z8_w_sb_alt_gpj_conceptual_rev_b__838.pdf
>
>
>
>
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
>
>
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Catch diode location |
Eric and Bob McC,
My EFIS maker, Advanced Flight Systems, wants spike suppression on every relay.
OK, so I can just put a bi-directional zener across all the relay/contactor coils
in the plane and I'm good for spike catching? Including the Alt 2 relay?
I've also got a small 5vdc coil (40ma) driven by an optical switch (another relay).
Does it get a spike catcher too?
So how does one size a bi-di-zener for spike catching?
Thanks,
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=315917#315917
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Strobe Noise Low Voltage? |
Mike -
If I remember your quandary correctly, it makes perfect sense. I think you
reported that you had a noise issue, and separating the strobe and audio
lines made it better. As you deplete the battery, the problem returns and
gets worse as the voltage declines.
Your strobes want (demand) a nominal amount of POWER (E*I) to operate. As
voltage sags, current must rise to meet the power requirement of the
appliance. Current flowing in a conductor generates an electromagnetic
field. The higher the current, the larger the EM field (there's a quadratic
or integral relationship there, but it's too rusty to remember).
neal
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of MHerder
Sent: Friday, October 15, 2010 2:08 PM
Subject: AeroElectric-List: Re: Strobe Noise Low Voltage?
<michaelherder@beckgroup.com>
I'm not intentionally testing it that low, it's just that I'm not flying and
I'm only running the engine every couple of weeks. I've spent hours upon
hours trying to find my strobe noise issue. In the mean time, I'm realizing
that I haven't charged the battery and all the while my strobes are draining
battery.
Last night it just occured to me that my problem might just be related to
that. And, I dont care if there is strobe noise at 10V as long as that is
the issue and not a poor ground or something similar.
--------
One Rivet at a Time!
Message 14
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Catch diode location |
John;
Yes, or just use the 1N5400's you've already shown for your battery
contactor on everything. Either will work. The perceived disadvantage to the
plain diode is that it does slow the reaction time of the device slightly,
but this will be undetectable for all practical intents and purposes.
(Advantages, really cheap, available anywhere)
Check Eric's website for explanations of the zeners. (Which he happens to
sell under the name "snapjack". They are also available from the major
electronics suppliers as bi-directional zeners)
http://www.periheliondesign.com/suppressors.htm
Any coil carrying a current will generate some level of reverse voltage when
switched off. So technically, yes, your small 5vdc coil will exhibit the
effect. Is it of any significance? Most likely not, especially as many
optical switches have suppression built in. The greatest effects are from
relatively large currents in relatively large inductors. (Like the one amp
of holding current in the multi turn winding of the battery contactor)
Bob McC
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-
> server@matronics.com] On Behalf Of jonlaury
> Sent: Friday, October 15, 2010 9:01 PM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Re: Catch diode location
>
>
> Eric and Bob McC,
> My EFIS maker, Advanced Flight Systems, wants spike suppression on every
relay.
> OK, so I can just put a bi-directional zener across all the
relay/contactor coils in the
> plane and I'm good for spike catching? Including the Alt 2 relay?
>
> I've also got a small 5vdc coil (40ma) driven by an optical switch
(another relay).
> Does it get a spike catcher too?
>
> So how does one size a bi-di-zener for spike catching?
>
> Thanks,
> John
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=315917#315917
>
>
>
>
>
>
>
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
> _-
> ====================================================
> ======
>
>
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! --
|