Today's Message Index:
----------------------
1. 12:18 AM - What's Being Said... (Matt Dralle)
2. 05:50 AM - David Clark ENC connector (Dave Durakovich)
3. 06:06 AM - Re: Recommended chargers for Odyssey batteries (David E. Nelson)
4. 06:09 AM - Re: Re: Risks to Deltran Battery Tender Jr. (John Huft)
5. 06:26 AM - Risks to Deltran Battery Tender Jr. (rd2@evenlink.com)
6. 07:30 AM - Re: Risks to Deltran Battery Tender Jr. (Robert L. Nuckolls, III)
7. 07:31 AM - Re: Recommended chargers for Odyssey (Robert L. Nuckolls, III)
8. 08:43 AM - battery tender post-mortem (John Huft)
9. 08:52 AM - Re: Bench and ground power supply (LarryRobertHelming)
10. 09:01 AM - Re: Variac (John Burnaby)
11. 09:26 AM - IR Alternator post mortem...Kinda (Hinde, Frank George (Corvallis))
12. 09:59 AM - David Clark ENC connector (Dave Durakovich)
13. 10:14 AM - Re:Batt charger (Paul Wilson)
14. 02:23 PM - Re: battery tender post-mortem version=3.0.3 (John Huft)
15. 03:25 PM - Nav coax and strobe wiring in same conduit ()
Message 1
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| Subject: | What's Being Said... |
--> AeroElectric-List message posted by: Matt Dralle <dralle@matronics.com>
Dear Listers,
First, I'd like say *thank you* to everyone that has already made a Contribution
during this year's List Fund Raiser! If you haven't made your List Contribution
yet, won't you show your support for these valuable services today? Since
there's no advertising or other forms of direct commercialism on these forums,
its solely YOUR GENEROSITY that keeps them running!!
Members have been including some very nice comments along with their Contributions
this year. Please take a minute to read over some of the thoughts your fellow
Listers have expressed regarding the Lists and what they mean to them. What
do the Lists mean to you...?
Please make a Contribution to support the Lists here:
http://www.matronics.com/contribution
Thank you!
Matt Dralle
Matronics Email List Admin
==================== What Listers Are Saying ====================
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==================== What Listers Are Saying ====================
Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551
925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email
http://www.matronics.com/ WWW | Featuring Products For Aircraft
do not archive
Message 2
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| Subject: | David Clark ENC connector |
--> AeroElectric-List message posted by: Dave Durakovich <ddurakovich@yahoo.com>
Anyone have a part number on the quick connector that David Clark uses on their
ENC headsets (ie; H20-10X) ? It's a 10 pin mini circular plug with a quick connect
(air hose type pull back) feature.
Thanks,
Dave Durakovich
Message 3
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| Subject: | Re: Recommended chargers for Odyssey batteries |
11/07/2005 08:05:18 AM,
Serialize by Router on MailServ58-US/AUS/H/NIC(653FP1HF290|September 14,
2005) at
11/07/2005 08:05:26 AM,
Serialize complete at 11/07/2005 08:05:26 AM
--> AeroElectric-List message posted by: "David E. Nelson" <david.nelson@pobox.com>
Don't know if this applies to the Junior models or not, but the "Battery Tender
PLUS" models that I have (5+ yrs old) require that the battery have a minimum
voltage present before it will "turn on". This was spelled out in the manual.
Regards,
/\/elson
On Sat, 5 Nov 2005, Robert L. Nuckolls, III wrote:
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
batteries
>
> At 05:29 PM 11/4/2005 -0700, you wrote:
>
>> --> AeroElectric-List message posted by: John Huft <aflyer@lazy8.net>
>>
>> Recently, I hooked up a Deltran charger (the junior, 0.75 Amp) to my
>> wife's car, as I did all last winter. This time however, I left the hood
>> open, with the underhood light on. The light draws more than the charger
>> can source, so, when I returned a week later, the battery was dead. No
>> surprising.
>>
>> The surprise, though, was that the charger was also dead. I took it
>> apart, and saw that the output transistor, attached to a large heatsink,
>> was a TO-220 package. There was no sign of an internal fuse (there is
>> one in the battery lead, which was still good), so I assume there is a
>> solid state type current limit circuit in the base of the output
>> transistors. Having designed these circuits (I am assuming that it is
>> not a crowbar type, but just a cheapo limiter), I know that they work
>> well for momentary shorts, but if the short persists, the output
>> transistor has to dissipate the rated current (.75A) times the voltage
>> (14) totaling 10.5 Watts. The TO-220 package is usually a 5 Watt deal
>> even with the heatsink, so I am thinking that is what killed the
>> charger. I confess I have not tested anything...just returned the charger.
>>
>> Similarly, I would think a completely dead battery would present the
>> same situation to the charger. So, I am thinking maybe the problem is
>> not related to the battery at all, but rather to the charger????????
>
>
> Great data point John. I just took one of my Deltran juniors and
> set it up on the bench with a capacitor and sufficient load to emulate
> a perpetually dead battery. Let's see what happens.
>
> These are "smart chargers" . . . they produce a much more sophisticated
> charging profile that could not be accomplished with a simple "limiter".
>
> See:
>
> http://batterytender.com/includes/languages/english/resources/Product_Info_BT_Junior.pdf
>
> If your autopsy didn't reveal a very high parts count, perhaps
> they've used a micro-controller to do the "smarts" . . . It's possible do
> dance very fancy footwork in the digital world at very low cost. I have
> a couple of products under development that will use the PIC12F675
> microcontroller . . .
>
> http://ww1.microchip.com/downloads/en/DeviceDoc/41190c.pdf
>
> This critter has a 10-bit a/d converter, reset generator and clock on
> on-board. Sells for about $1 in quantity.
>
> There's no good reason to do anything in discrete parts. Even $20 coffee
> makers are processor controlled.
>
> Your experience with an extraordinary stress on the Battery Tender is
> worth understanding. We'll see how my experiment goes and then if I kill
> the critter, I'll tear it apart and see what the autopsy reveals. Perhaps
> we can offer some good feedback to the folks at Deltran. Thanks for
> bringing your experience to the List.
>
> Bob . . .
--
~~ ** ~~ If you don't think to well, then don't think to much. ~~ ** ~~
Message 4
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| Subject: | Re: Risks to Deltran Battery Tender Jr. |
version=3.0.3
--> AeroElectric-List message posted by: John Huft <aflyer@lazy8.net>
Well, Bob, that was a fun test.
Thermally, your 10 Volts at 1 Amp was the same power level as 14 V at
.75 A, so I guess the 70 dC temp was within design specs, and we know
that is within the range for power transistors.
I think my test was even more severe, since as the battery gradually ran
down, the current drain went up, and especially if the current limit is
software controlled, is the opposite of what the designer would expect,
and may well have fooled the unit. I would even say it was 'unfair' to
the charger, and I don't think any less of Deltran for the failure.
I still have the charger, and will take a look at it this morning, and
will either report results or send it to you if I don't find anything.
John
Robert L. Nuckolls, III wrote:
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
>
>
> >Question:
> >
> >Will the Deltran Battery Tender Jr. be at risk for damage due to
> >long term connection to a battery that cannot be charged and/or
> >has some fixed load across the battery that exceeds the rated output
> >current of the charger?
> >
> This question offers and excellent opportunity to discuss
> thermal modeling of an electronic device and to introduce
> the concept of thermal resistance. To begin the discussion,
> it was useful to conduct a simple test on the product.
> Let's gather some rudimentary data on a Battery Tender Jr.
> under extra-ordinary stress and see what we can deduce about
> its operation and probability of survival:
>
> The experiment . . .
>
> Step 1: Connect Deltran Battery Tender Jr. across a 10 ohm resistor
> paralleled with a 10,000 uF capacitor. Plug in wall.
>
> Observation 1: Note that the Battery Tender does not come alive.
>
> Hypothesis A: Circuitry in the charger senses whether or not
> there is some semblance of a battery connected. Zero volts
> could be either a dead short or a battery that is totally trashed.
> The circuit is designed not to attempt a recharge cycle under
> these conditions.
>
> Step 2. Temporarily connect 12v battery across the load array.
>
> Observation 2: Charger's red light comes on indicating that it
> has gone to work.
>
> Step 3. Connect voltmeter across the load array.
>
> Observation 2: Voltmeter shows 10.2 volts across the load array.
>
> Deduction: 10.2v at 10 ohms is right at 1.0 amp. The Deltran Battery
> Tender Jr. is rated at 0.75A. Obviously, there are no features that
> limit current to the rated value. This initial test setup has already
> overloaded the device by 33%.
>
> Step 4. Wait.
>
> Observation 3: After an hour of operation, the case, particularly
> next to the wall was pretty toasty. (Toasty: engineering term for
> operating temperatures between "warm to touch" and "starting to
> stink". The hottest surfaces were sides closest to the wall outlet.
>
> Step 5. Add thermocouple to hottest surface and continue testing
>
> Observation: 10 minutes after restart, case temperature is up to
> 65C.
>
> Step 6. Wait.
>
> Observation 4: After continuous operation overnight, the output
> current from the Battery Tender was still holding at 1.05 amps.
> The case temperature had stabilized at 69 degrees C in a 23 degree
> C environment.
>
> What might we deduce from this little bit of data and how
> does it offer insight into the failure reported by John Huft.
> Let's review his observations:
> >--> AeroElectric-List message posted by: John Huft <aflyer@lazy8.net>
> >
> > Recently, I hooked up a Deltran charger (the junior, 0.75 Amp) to my
> >wife's car, as I did all last winter. This time however, I left the hood
> >open, with the underhood light on. The light draws more than the charger
> >can source, so, when I returned a week later, the battery was dead. No
> >surprising.
> >
> >The surprise, though, was that the charger was also dead. I took it
> >apart, and saw that the output transistor, attached to a large heatsink,
> >was a TO-220 package. There was no sign of an internal fuse (there is
> >one in the battery lead, which was still good), so I assume there is a
> >solid state type current limit circuit in the base of the output
> >transistors. Having designed these circuits (I am assuming that it is
> >not a crowbar type, but just a cheapo limiter), I know that they work
> >well for momentary shorts, but if the short persists, the output
> >transistor has to dissipate the rated current (.75A) times the voltage
> >(14) totaling 10.5 Watts. The TO-220 package is usually a 5 Watt deal
> >even with the heatsink, so I am thinking that is what killed the
> >charger. I confess I have not tested anything...just returned the charger.
> >
> >Similarly, I would think a completely dead battery would present the
> >same situation to the charger. So, I am thinking maybe the problem is
> >not related to the battery at all, but rather to the charger????????
>
> John's questions about over-heating of the major power handling
> device in the charger is a good one. By the way John, if you still
> have the smoked charger, I'd sure like to get my hands on it. Since
> I didn't smoke the charger I used in the experiment, I'm reluctant
> to saw it open for more detailed inspection . . . but if your dead
> one is available, it would add some additional insight into the
> functionality and vulnerabilities of this product.
>
> Why didn't my Battery Tender smoke? Perhaps John's environment
> was warmer. Perhaps his particular battery/load combination pulled
> the charger's output lower than my experiment (10 volts) and caused
> it to get hotter.
>
> Given the temperature rise we measured, I'd estimate that my
> experiment forced the Battery Tender into an internal dissipation
> level on the order of 10 watts. It seems likely that long term
> operation in this condition might put the critter at risk for
> smoke.
>
> I note that Deltran's instruction sheet for this charge does not
> speak against charging large batteries (even a heavily discharged
> battery will rise above 11 volts in under an hour). I've used
> my Deltran BT Jr.s to recharge all sizes of batteries in every
> state of discharge with good results.
>
> I don't think we've learned anything from this experiment that
> suggests my confidence and recommendations for use of the Deltran
> BT Jr. needs modification. Our mini-investigation suggests that
> the continuous, unintended loading of the battery was the proximate
> cause of failure . . . and not a deficiency in the design of the
> charger.
>
> Bob . . .
>
>
>
>
>
>
>
>
>
Message 5
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| Subject: | Risks to Deltran Battery Tender Jr. |
--> AeroElectric-List message posted by: rd2@evenlink.com
I have been looking for a charger/maintainer per the following requirements:
-be able to recharge a fully discharged battery
-be able to maintain a battery; be able to switch between pulsing, current
and voltage modes
-have short protection preferably electronic, no fuses to replace)
-no current drain when connected to battery but no AC in (unplugged or
power outage)
-operate on various voltages
After looking at various options, the Soneil 1205 SR (for 12 V batteries)
and 2403 SR (for 24 V batteries) seemed to fulfill the above requirements.
URL:
http://www.soneil.com/Completesets/SPEC1205SR(REV%2003).17-Jun-04.pdf
I have been using it for about 2 years without interruption (when the plane
is on the ground that is :) and am very pleased.
The battery (even one that was over 4 years old and abused) responds and
charges fully (albeit slower as compared to a large charger) as long as
there is some minimal voltage left in it - the charger begins to charge
current.
The unit also has an "inhibit lead", which provides an inhibit signal to
the vehicle's controller, so that the controller stops the vehicle from
moving when the charger is plugged to an AC source.
Bob et all - any comments, feedback, experience with this unit?
Rumen
_____________________Original message __________________________
(received from Robert L. Nuckolls, III; Date: 10:18 PM
11/6/2005 -0600)
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<nuckollsr@cox.net>
>Question:
>
>Will the Deltran Battery Tender Jr. be at risk for damage due to
>long term connection to a battery that cannot be charged and/or
>has some fixed load across the battery that exceeds the rated output
>current of the charger?
>
This question offers and excellent opportunity to discuss
thermal modeling of an electronic device and to introduce
the concept of thermal resistance. To begin the discussion,
it was useful to conduct a simple test on the product.
Let's gather some rudimentary data on a Battery Tender Jr.
under extra-ordinary stress and see what we can deduce about
its operation and probability of survival:
The experiment . . .
Step 1: Connect Deltran Battery Tender Jr. across a 10 ohm resistor
paralleled with a 10,000 uF capacitor. Plug in wall.
Observation 1: Note that the Battery Tender does not come alive.
Hypothesis A: Circuitry in the charger senses whether or not
there is some semblance of a battery connected. Zero volts
could be either a dead short or a battery that is totally trashed.
The circuit is designed not to attempt a recharge cycle under
these conditions.
Step 2. Temporarily connect 12v battery across the load array.
Observation 2: Charger's red light comes on indicating that it
has gone to work.
Step 3. Connect voltmeter across the load array.
Observation 2: Voltmeter shows 10.2 volts across the load array.
Deduction: 10.2v at 10 ohms is right at 1.0 amp. The Deltran Battery
Tender Jr. is rated at 0.75A. Obviously, there are no features that
limit current to the rated value. This initial test setup has already
overloaded the device by 33%.
Step 4. Wait.
Observation 3: After an hour of operation, the case, particularly
next to the wall was pretty toasty. (Toasty: engineering term for
operating temperatures between "warm to touch" and "starting to
stink". The hottest surfaces were sides closest to the wall outlet.
Step 5. Add thermocouple to hottest surface and continue testing
Observation: 10 minutes after restart, case temperature is up to
65C.
Step 6. Wait.
Observation 4: After continuous operation overnight, the output
current from the Battery Tender was still holding at 1.05 amps.
The case temperature had stabilized at 69 degrees C in a 23 degree
C environment.
What might we deduce from this little bit of data and how
does it offer insight into the failure reported by John Huft.
Let's review his observations:
>--> AeroElectric-List message posted by: John Huft <aflyer@lazy8.net>
>
> Recently, I hooked up a Deltran charger (the junior, 0.75 Amp) to my
>wife's car, as I did all last winter. This time however, I left the hood
>open, with the underhood light on. The light draws more than the charger
>can source, so, when I returned a week later, the battery was dead. No
>surprising.
>
>The surprise, though, was that the charger was also dead. I took it
>apart, and saw that the output transistor, attached to a large heatsink,
>was a TO-220 package. There was no sign of an internal fuse (there is
>one in the battery lead, which was still good), so I assume there is a
>solid state type current limit circuit in the base of the output
>transistors. Having designed these circuits (I am assuming that it is
>not a crowbar type, but just a cheapo limiter), I know that they work
>well for momentary shorts, but if the short persists, the output
>transistor has to dissipate the rated current (.75A) times the voltage
>(14) totaling 10.5 Watts. The TO-220 package is usually a 5 Watt deal
>even with the heatsink, so I am thinking that is what killed the
>charger. I confess I have not tested anything...just returned the charger.
>
>Similarly, I would think a completely dead battery would present the
>same situation to the charger. So, I am thinking maybe the problem is
>not related to the battery at all, but rather to the charger????????
John's questions about over-heating of the major power handling
device in the charger is a good one. By the way John, if you still
have the smoked charger, I'd sure like to get my hands on it. Since
I didn't smoke the charger I used in the experiment, I'm reluctant
to saw it open for more detailed inspection . . . but if your dead
one is available, it would add some additional insight into the
functionality and vulnerabilities of this product.
Why didn't my Battery Tender smoke? Perhaps John's environment
was warmer. Perhaps his particular battery/load combination pulled
the charger's output lower than my experiment (10 volts) and caused
it to get hotter.
Given the temperature rise we measured, I'd estimate that my
experiment forced the Battery Tender into an internal dissipation
level on the order of 10 watts. It seems likely that long term
operation in this condition might put the critter at risk for
smoke.
I note that Deltran's instruction sheet for this charge does not
speak against charging large batteries (even a heavily discharged
battery will rise above 11 volts in under an hour). I've used
my Deltran BT Jr.s to recharge all sizes of batteries in every
state of discharge with good results.
I don't think we've learned anything from this experiment that
suggests my confidence and recommendations for use of the Deltran
BT Jr. needs modification. Our mini-investigation suggests that
the continuous, unintended loading of the battery was the proximate
cause of failure . . . and not a deficiency in the design of the
charger.
Bob . . .
--
Checked by AVG Free Edition.
Message 6
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| Subject: | Re: Risks to Deltran Battery Tender Jr. |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 07:10 AM 11/7/2005 -0700, you wrote:
>--> AeroElectric-List message posted by: John Huft <aflyer@lazy8.net>
>
>Well, Bob, that was a fun test.
>
>Thermally, your 10 Volts at 1 Amp was the same power level as 14 V at
>.75 A, so I guess the 70 dC temp was within design specs, and we know
>that is within the range for power transistors.
Keep in mind that power dissipated within a device is a function
of the voltage drop across the device times the current through it.
The most severe test would be a dead-short on a charger that is
not current limited nor fitted with a low voltage inhibit. In this
case OUTPUT voltage is zero, ALL voltage from the transformer-rectifier
is dropped internally at whatever current the system would deliver.
I stuck an extra 10 ohm resistor across the load on yesterday's
experiment, voltage dropped to 6.5 volts. Okay, 6.5v/5ohms = 1.3 A.
I put a dead short on it and the system shut down.
Assuming a linear relationship for the current rise, a very low ohms
load might peak the output current at say 1.5A. Under this condition,
nearly ALL voltage would be dropped inside the device and internal
dissipation would be on the order of 14 x 1.5 or 21 watts.
When the charger is working full-out at 0.75A into a normal battery
the internal drop might be something on the order of 4v at 0.75A
for an dissipation value of 3 watts. Also, keep in mind that the
70C measured was on the case . . . The thermal model for the
battery charger looks something like this:
http://www.aeroelectric.com/Pictures/Misc/Deltran_T_Model.gif
There is a host of thermal resistances between the device that
gets hot (transistor) and the case. Most power junctions are
good for 150C. To fully analyze the risk to the power device,
we would need to know a great deal more about these thermal
resistances . . . or better yet, go inside and thermocouple
the device itself. It's a sure bet that it was a LOT hotter
than the 70C we were measuring outside on the surface.
>I think my test was even more severe, since as the battery gradually ran
>down, the current drain went up, and especially if the current limit is
>software controlled, is the opposite of what the designer would expect,
>and may well have fooled the unit. I would even say it was 'unfair' to
>the charger, and I don't think any less of Deltran for the failure.
The Deltran BT Jr exhibits no evidence of features designed to
limit current . . . else I would expect it to be 0.75A max under
all operating conditions. Considering the characteristics we've been
able to observe from outside: If your "ruggedness test" stabilized
out anywhere between 4 and 10 volts that the output current would
be on the order of 1 to 1.6 amps and total device dissipations in the
10 to 16 watt range. If you WERE running 16w, then case temperature
could have been expected to rise about 60% more than the experiment
I conducted. This would put the case at about 100C and most
definitely place any 150C power device at risk.
>I still have the charger, and will take a look at it this morning, and
>will either report results or send it to you if I don't find anything.
Great. I'd be pleased to see it.
Bob . . .
Message 7
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| Subject: | RE: Recommended chargers for Odyssey |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 08:05 AM 11/7/2005 -0600, you wrote:
>--> AeroElectric-List message posted by: "David E. Nelson"
><david.nelson@pobox.com>
>
>
>Don't know if this applies to the Junior models or not, but the "Battery
>Tender
>PLUS" models that I have (5+ yrs old) require that the battery have a minimum
>voltage present before it will "turn on". This was spelled out in the manual.
I'm certain that this is a feature of all the Deltran products. They
would not start without a "boost" from the battery and when dead
shorted, it shut down.
Bob . . .
Message 8
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| Subject: | battery tender post-mortem |
version=3.0.3
--> AeroElectric-List message posted by: John Huft <aflyer@lazy8.net>
Hi Bob
I took the failed unit apart (I haven't figured out how to return the
unit anyway, emails unanswered).
There is heat damage on the back of the P.C. board under the output
transistor. This is actually a Fairchild BD-434 PNP in a TO-126 package.
The data sheet says it will source 3 Amps at 10 Volts if you can keep
the temp down, which I doubt you can with a piece of sheet Al for a
heatsink inside a small plastic box. Of course you are right about the
difference in temp between outside of the case and the transistor junction.
There is no microP on the board, the only IC is a 348 dual op-amp. There
is also heat damage on the board under the bridge rectifier.
You are right, I was comparing power into the loads before. I was still
assuming some sort of linear type current limiting, but I agree that
your tests show nothing more than a source impedance. It is hard to say
what the voltage drop across the output transistor is without measuring
it, since the transformer, bridge rectifier, and filter circuits all
contribute to the voltage drops under load.
The op-amp may just shut the unit down below a certain voltage on the
output, and the other half control the float voltage, or something like
that. I think if you keep paralleling resistors on your load setup, it
will either shut down, or if you do it slowly enough, burn up. Again, I
feel this is unfair torture to an inexpensive charger.
Looks to me like the full-blown, switcher based, microP controlled units
like the one Rumen referenced will eventually win out.
If you want me to send the corpse to you, drop me an address.
John
Robert L. Nuckolls, III wrote:
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
>
> At 07:10 AM 11/7/2005 -0700, you wrote:
>
>
>>--> AeroElectric-List message posted by: John Huft <aflyer@lazy8.net>
>>
>>Well, Bob, that was a fun test.
>>
>>Thermally, your 10 Volts at 1 Amp was the same power level as 14 V at
>>.75 A, so I guess the 70 dC temp was within design specs, and we know
>>that is within the range for power transistors.
>
>
> Keep in mind that power dissipated within a device is a function
> of the voltage drop across the device times the current through it.
> The most severe test would be a dead-short on a charger that is
> not current limited nor fitted with a low voltage inhibit. In this
> case OUTPUT voltage is zero, ALL voltage from the transformer-rectifier
> is dropped internally at whatever current the system would deliver.
> I stuck an extra 10 ohm resistor across the load on yesterday's
> experiment, voltage dropped to 6.5 volts. Okay, 6.5v/5ohms = 1.3 A.
> I put a dead short on it and the system shut down.
>
> Assuming a linear relationship for the current rise, a very low ohms
> load might peak the output current at say 1.5A. Under this condition,
> nearly ALL voltage would be dropped inside the device and internal
> dissipation would be on the order of 14 x 1.5 or 21 watts.
>
> When the charger is working full-out at 0.75A into a normal battery
> the internal drop might be something on the order of 4v at 0.75A
> for an dissipation value of 3 watts. Also, keep in mind that the
> 70C measured was on the case . . . The thermal model for the
> battery charger looks something like this:
>
> http://www.aeroelectric.com/Pictures/Misc/Deltran_T_Model.gif
>
> There is a host of thermal resistances between the device that
> gets hot (transistor) and the case. Most power junctions are
> good for 150C. To fully analyze the risk to the power device,
> we would need to know a great deal more about these thermal
> resistances . . . or better yet, go inside and thermocouple
> the device itself. It's a sure bet that it was a LOT hotter
> than the 70C we were measuring outside on the surface.
>
>
>
>>I think my test was even more severe, since as the battery gradually ran
>>down, the current drain went up, and especially if the current limit is
>>software controlled, is the opposite of what the designer would expect,
>>and may well have fooled the unit. I would even say it was 'unfair' to
>>the charger, and I don't think any less of Deltran for the failure.
>
>
> The Deltran BT Jr exhibits no evidence of features designed to
> limit current . . . else I would expect it to be 0.75A max under
> all operating conditions. Considering the characteristics we've been
> able to observe from outside: If your "ruggedness test" stabilized
> out anywhere between 4 and 10 volts that the output current would
> be on the order of 1 to 1.6 amps and total device dissipations in the
> 10 to 16 watt range. If you WERE running 16w, then case temperature
> could have been expected to rise about 60% more than the experiment
> I conducted. This would put the case at about 100C and most
> definitely place any 150C power device at risk.
>
>
>
>>I still have the charger, and will take a look at it this morning, and
>>will either report results or send it to you if I don't find anything.
>
>
> Great. I'd be pleased to see it.
>
> Bob . . .
>
>
>
>
>
>
>
>
>
Message 9
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| Subject: | Re: Bench and ground power supply |
--> AeroElectric-List message posted by: "LarryRobertHelming" <lhelming@sigecom.net>
What is the down side to using one of these for a battery charger?
Indiana Larry
----- Original Message -----
Subject: AeroElectric-List: Bench and ground power supply
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <nuckollsr@cox.net>
>
> Just ran across this item on the 'net.
>
> http://www.web-tronics.com/25ampswitpow.html
>
>
> This supply is adjustable to 9-15 volts meaning that
> you can set it to emulate an alternator at 14.2 volts.
> Better yet, it's metered.
>
>
> Bob . . .
Message 10
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--> AeroElectric-List message posted by: "John Burnaby" <jonlaury@impulse.net>
Could one not connect the appropriate # of D cells in series for a poor man's variac
for a one time solution?
I too have a Whelen system that will need some rejuvenation from prolonged storage.
John
Message 11
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| Subject: | IR Alternator post mortem...Kinda |
--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
Bob thankyou for your kind offer to send you my IR alt that was
behaving erratically. Suspecting it was just the brushes I thought it
worth opening up the case to see if it was something simple.
I found that the oil leak from the sump filler cap had been lubricating
the back of my alternator and the slip ring brush interface had a nice
greasy goop made of oil and brush material covering the slip rings.
Definatly looks like this has been lifting the brushes off the slip
rings.
The inside of the alt has a lot of this stuff and the first thing I will
do is clean it up and reinstall it on the airplane, having found an
assignable cause.
So the easy question is what sort of solvent should I use? I have some
acetone but I'm concerned I mught remove shellac from the windings and
or melt the plastic parts.
Any suggestions??
Thanks
Frank
Message 12
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| Subject: | David Clark ENC connector |
--> AeroElectric-List message posted by: Dave Durakovich <ddurakovich@yahoo.com>
Anyone have a part number on the quick connector that David Clark uses on their
ENC headsets (ie; H20-10X) ? It's a 10 pin mini circular plug with a quick connect
(air hose type pull back) feature.
Thanks,
Dave Durakovich
Message 13
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--> AeroElectric-List message posted by: Paul Wilson <pwmac@sisna.com>
FYI,
My Schumacher 1562A wont charge a low battery. It goes into overload and
shuts off (red light on). The drill is up unplug it for 5 seconds to reset
it. I finally put the flooded cell car battery on a 2 amp charger all day
then put the 1562A on and it worked without a overload. I left the thing
for a month and when I got back the green light was on indicating voltage
above 13.2. Nice to have a fully charged battery after it sitts a while.
Regards, Paul W
Message 14
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| Subject: | Re: battery tender post-mortem version=3.0.3 |
version=3.0.3
--> AeroElectric-List message posted by: John Huft <aflyer@lazy8.net>
John Huft wrote:
> --> AeroElectric-List message posted by: John Huft <aflyer@lazy8.net>
>
> Hi Bob
>
> I took the failed unit apart (I haven't figured out how to return the
> unit anyway, emails unanswered).
I want to correct the above, they answered me after I posted this...they
will replace the unit for $9.95 S&H, I think fair enough, but I am not
going to do it, I feel like I broke it.
John
Message 15
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| Subject: | Nav coax and strobe wiring in same conduit |
--> AeroElectric-List message posted by: <bbradburry@allvantage.com>
My Legacy has a nav antenna in the wing tip. The position and strobe lights
are also there and there is only one conduit to bring the wireing into the
fuselage. Is there going to be a problem with this setup and should I do
something special to these cables? The nav antenna will be connected with
crimp ring connectors. I know I should keep these short. Anything else?
Bill Bradburry
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