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bobnoffs



Joined: 04 Jul 2012
Posts: 99
Location: northern wi.

PostPosted: Sun Mar 31, 2019 4:27 am    Post subject: ov warning light Reply with quote

hi all,
i put together an ov''crowbar '' for the output side of my alternator but in the end i didn't use it. instead i made a warning light from a 2.2v 20ma. led, 3 resistors totaling 1700 ohms and a 13v zenor diode. at 14v it very faintly glows which is good to see that it is working. at 15.06 v it glows brightly. not much difference between 10ma. and 20ma. in brightness so i have some leeway up to 30 volts. this warning is to protect 2 earthx batteries. whether or not i need it is a question but i gotta do something with that hole in the panel.
bob noffs


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PostPosted: Sun Mar 31, 2019 4:17 pm    Post subject: ov warning light Reply with quote

At 07:27 AM 3/31/2019, you wrote:
Quote:
--> AeroElectric-List message posted by: "bobnoffs" <icubob(at)gmail.com>

hi all,
i put together an ov'crowbar ' for the output side of my alternator but in the end i didn't use it. instead i made a warning light from a 2.2v 20ma. led, 3 resistors totaling 1700 ohms and a 13v zenor diode. at 14v it very faintly glows which is good to see that it is working. at 15.06 v it glows brightly. not much difference between 10ma. and 20ma. in brightness so i have some leeway up to 30 volts. this warning is to protect 2 earthx batteries. whether or not i need it is a question but i gotta do something with that hole in the panel.

EarthX battery BMS will protect the
batteries. The BMS will not protect
your avionics. If the BMS DISCONNECTS
the battery from a runaway alternator,
the bus voltage climbs at a VERY rapid
rate.

Unless your ov warning is BRIGHT, SUNLIGHT
VIEWABLE, and FLASHES to trigger your
Japanese kick boxer-reflexes . . . chances
for making lots of transistor-toast is
significant . . . but the batteries
will be fine.



Bob . . .


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bobnoffs



Joined: 04 Jul 2012
Posts: 99
Location: northern wi.

PostPosted: Sun Mar 31, 2019 6:35 pm    Post subject: ov warning light Reply with quote

hi bob, yea, i know. and all i am doing it for is the batteries. after asking a lot of questions about this over several months it seems hardly anyone is doing  anything to protect transistors. 
 bob noffs
On Sun, Mar 31, 2019 at 7:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
At 07:27 AM 3/31/2019, you wrote:
Quote:
--> AeroElectric-List message posted by: "bobnoffs" <icubob(at)gmail.com (icubob(at)gmail.com)>

hi all,
 i put together an ov'crowbar ' for the output side of my alternator but in the end i didn't use it. instead i made a warning light from a 2.2v  20ma. led, 3 resistors totaling 1700 ohms and a 13v zenor diode. at 14v it very faintly glows which is good to see that it is working. at 15.06 v it glows brightly. not much difference between 10ma. and 20ma. in brightness so i have some  leeway up to 30 volts. this warning is to protect 2 earthx batteries. whether or not i need it is a question but i gotta do something with that hole in the panel.

 EarthX battery BMS will protect the
 batteries. The BMS will not protect
 your avionics. If the BMS DISCONNECTS
 the battery from a runaway alternator,
 the bus voltage climbs at a VERY rapid
 rate.

 Unless your ov warning is BRIGHT, SUNLIGHT
 VIEWABLE, and FLASHES to trigger your
 Japanese kick boxer-reflexes . . . chances
 for making lots of transistor-toast is
 significant . . . but the batteries
 will be fine.



  Bob . . .


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PostPosted: Sun Mar 31, 2019 6:46 pm    Post subject: ov warning light Reply with quote

Hi Bob,

Who are you asking? Smile

Charlie

On 3/31/2019 9:33 PM, bob noffs wrote:

Quote:
hi bob,  yea, i know. and all i am doing it for is the batteries. after asking a lot of questions about this over several months it seems hardly anyone is doing  anything to protect transistors. 
 bob noffs


On Sun, Mar 31, 2019 at 7:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
At 07:27 AM 3/31/2019, you wrote:
Quote:
--> AeroElectric-List message posted by: "bobnoffs" <icubob(at)gmail.com (icubob(at)gmail.com)>

hi all,
 i put together an ov'crowbar ' for the output side of my alternator but in the end i didn't use it. instead i made a warning light from a 2.2v  20ma. led, 3 resistors totaling 1700 ohms and a 13v zenor diode. at 14v it very faintly glows which is good to see that it is working. at 15.06 v it glows brightly. not much difference between 10ma. and 20ma. in brightness so i have some  leeway up to 30 volts. this warning is to protect 2 earthx batteries. whether or not i need it is a question but i gotta do something with that hole in the panel.

 EarthX battery BMS will protect the
 batteries. The BMS will not protect
 your avionics. If the BMS DISCONNECTS
 the battery from a runaway alternator,
 the bus voltage climbs at a VERY rapid
 rate.

 Unless your ov warning is BRIGHT, SUNLIGHT
 VIEWABLE, and FLASHES to trigger your
 Japanese kick boxer-reflexes . . . chances
 for making lots of transistor-toast is
 significant . . . but the batteries
 will be fine.



  Bob . . .


Virus-free. www.avast.com [url=#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2] [/url]


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bobnoffs



Joined: 04 Jul 2012
Posts: 99
Location: northern wi.

PostPosted: Mon Apr 01, 2019 4:32 am    Post subject: ov warning light Reply with quote

hi charlie,probably viewers of this forum have the highest % of using an ovm. of 10 people i have personally talked to no one has one. many believe that it is in their alternator which i think is true in some cases but who knows which ones. yesterday on a forum one person said he was protected by the 60 amp inline fuse on his alternator output.   i would be surprised if you said everyone you knew had one.
 bob noffs
On Sun, Mar 31, 2019 at 9:50 PM Charlie England <ceengland7(at)gmail.com (ceengland7(at)gmail.com)> wrote:

Quote:
Hi Bob,

Who are you asking? Smile

Charlie

On 3/31/2019 9:33 PM, bob noffs wrote:

Quote:
hi bob,  yea, i know. and all i am doing it for is the batteries. after asking a lot of questions about this over several months it seems hardly anyone is doing  anything to protect transistors. 
 bob noffs


On Sun, Mar 31, 2019 at 7:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
At 07:27 AM 3/31/2019, you wrote:
Quote:
--> AeroElectric-List message posted by: "bobnoffs" <icubob(at)gmail.com (icubob(at)gmail.com)>

hi all,
 i put together an ov'crowbar ' for the output side of my alternator but in the end i didn't use it. instead i made a warning light from a 2.2v  20ma. led, 3 resistors totaling 1700 ohms and a 13v zenor diode. at 14v it very faintly glows which is good to see that it is working. at 15.06 v it glows brightly. not much difference between 10ma. and 20ma. in brightness so i have some  leeway up to 30 volts. this warning is to protect 2 earthx batteries. whether or not i need it is a question but i gotta do something with that hole in the panel.

 EarthX battery BMS will protect the
 batteries. The BMS will not protect
 your avionics. If the BMS DISCONNECTS
 the battery from a runaway alternator,
 the bus voltage climbs at a VERY rapid
 rate.

 Unless your ov warning is BRIGHT, SUNLIGHT
 VIEWABLE, and FLASHES to trigger your
 Japanese kick boxer-reflexes . . . chances
 for making lots of transistor-toast is
 significant . . . but the batteries
 will be fine.



  Bob . . .



Virus-free. www.avast.com [url=#m_-3003266867060444899_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2] [/url]



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PostPosted: Mon Apr 01, 2019 5:16 am    Post subject: ov warning light Reply with quote

OK, your answer illuminates the real question behind my half joking question: Who do you *trust* to answer your question? If your momma was like most, at some point she said something like, 
"If all your friends decided to jump off a cliff, would you do it too?"
I think from your answer you realize that most of the people you asked, had no idea what you were even talking about, much less were qualified to explain *why* they made the choice (because they never even made the choice). Obviously the guy with the 60A fuse had no clue. Not unlike the current crop of new parents, who read on Facebook that vaccinations might be dangerous, so now we've got outbreaks of measles and other really dangerous diseases putting others (who actually have good sense) at risk, and costing us millions in otherwise unnecessary health expenses.
Dimbulb governor

So really, shouldn't you be asking those who've had an OV event how their equipment fared, instead of asking those who've never needed one whether they have one? Or limit your ask to those who have the technical expertise to intelligently answer the question why they made their choice? I don't have one in my current RV-4, but it's a dirt simple day vfr a/c with mags firing the plugs, and the most expensive electrical item is the cheap, old comm in the panel. I'm just too busy and lazy to add OV protection to it. BUT: the RV-7 I'm building will have an electrically dependent engine with very expensive radios and instruments. You can bet that I already have OV protection built into both alternators on it.
Charlie
On Mon, Apr 1, 2019 at 7:37 AM bob noffs <icubob(at)gmail.com (icubob(at)gmail.com)> wrote:

Quote:
hi charlie,probably viewers of this forum have the highest % of using an ovm. of 10 people i have personally talked to no one has one. many believe that it is in their alternator which i think is true in some cases but who knows which ones. yesterday on a forum one person said he was protected by the 60 amp inline fuse on his alternator output.   i would be surprised if you said everyone you knew had one.
 bob noffs
On Sun, Mar 31, 2019 at 9:50 PM Charlie England <ceengland7(at)gmail.com (ceengland7(at)gmail.com)> wrote:

Quote:
Hi Bob,

Who are you asking? Smile

Charlie

On 3/31/2019 9:33 PM, bob noffs wrote:

Quote:
hi bob,  yea, i know. and all i am doing it for is the batteries. after asking a lot of questions about this over several months it seems hardly anyone is doing  anything to protect transistors. 
 bob noffs


On Sun, Mar 31, 2019 at 7:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
At 07:27 AM 3/31/2019, you wrote:
Quote:
--> AeroElectric-List message posted by: "bobnoffs" <icubob(at)gmail.com (icubob(at)gmail.com)>

hi all,
 i put together an ov'crowbar ' for the output side of my alternator but in the end i didn't use it. instead i made a warning light from a 2.2v  20ma. led, 3 resistors totaling 1700 ohms and a 13v zenor diode. at 14v it very faintly glows which is good to see that it is working. at 15.06 v it glows brightly. not much difference between 10ma. and 20ma. in brightness so i have some  leeway up to 30 volts. this warning is to protect 2 earthx batteries. whether or not i need it is a question but i gotta do something with that hole in the panel.

 EarthX battery BMS will protect the
 batteries. The BMS will not protect
 your avionics. If the BMS DISCONNECTS
 the battery from a runaway alternator,
 the bus voltage climbs at a VERY rapid
 rate.

 Unless your ov warning is BRIGHT, SUNLIGHT
 VIEWABLE, and FLASHES to trigger your
 Japanese kick boxer-reflexes . . . chances
 for making lots of transistor-toast is
 significant . . . but the batteries
 will be fine.



  Bob . . .



Virus-free. www.avast.com [url=#m_1344822525544774896_m_-3003266867060444899_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2] [/url]




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Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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bobnoffs



Joined: 04 Jul 2012
Posts: 99
Location: northern wi.

PostPosted: Mon Apr 01, 2019 5:49 am    Post subject: ov warning light Reply with quote

charlie, let's make the distinction between an ovm that is installed into the a/c system and the one that is supposedly in the alternator. i am sure some alternators have them but i have never seen any documentation about which alt. have it and how it is done.  bob noffs
On Mon, Apr 1, 2019 at 8:23 AM Charlie England <ceengland7(at)gmail.com (ceengland7(at)gmail.com)> wrote:

Quote:
OK, your answer illuminates the real question behind my half joking question: Who do you *trust* to answer your question? If your momma was like most, at some point she said something like, 
"If all your friends decided to jump off a cliff, would you do it too?"
I think from your answer you realize that most of the people you asked, had no idea what you were even talking about, much less were qualified to explain *why* they made the choice (because they never even made the choice). Obviously the guy with the 60A fuse had no clue. Not unlike the current crop of new parents, who read on Facebook that vaccinations might be dangerous, so now we've got outbreaks of measles and other really dangerous diseases putting others (who actually have good sense) at risk, and costing us millions in otherwise unnecessary health expenses.
Dimbulb governor

So really, shouldn't you be asking those who've had an OV event how their equipment fared, instead of asking those who've never needed one whether they have one? Or limit your ask to those who have the technical expertise to intelligently answer the question why they made their choice? I don't have one in my current RV-4, but it's a dirt simple day vfr a/c with mags firing the plugs, and the most expensive electrical item is the cheap, old comm in the panel. I'm just too busy and lazy to add OV protection to it. BUT: the RV-7 I'm building will have an electrically dependent engine with very expensive radios and instruments. You can bet that I already have OV protection built into both alternators on it.
Charlie
On Mon, Apr 1, 2019 at 7:37 AM bob noffs <icubob(at)gmail.com (icubob(at)gmail.com)> wrote:

Quote:
hi charlie,probably viewers of this forum have the highest % of using an ovm. of 10 people i have personally talked to no one has one. many believe that it is in their alternator which i think is true in some cases but who knows which ones. yesterday on a forum one person said he was protected by the 60 amp inline fuse on his alternator output.   i would be surprised if you said everyone you knew had one.
 bob noffs
On Sun, Mar 31, 2019 at 9:50 PM Charlie England <ceengland7(at)gmail.com (ceengland7(at)gmail.com)> wrote:

Quote:
Hi Bob,

Who are you asking? Smile

Charlie

On 3/31/2019 9:33 PM, bob noffs wrote:

Quote:
hi bob,  yea, i know. and all i am doing it for is the batteries. after asking a lot of questions about this over several months it seems hardly anyone is doing  anything to protect transistors. 
 bob noffs


On Sun, Mar 31, 2019 at 7:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
At 07:27 AM 3/31/2019, you wrote:
Quote:
--> AeroElectric-List message posted by: "bobnoffs" <icubob(at)gmail.com (icubob(at)gmail.com)>

hi all,
 i put together an ov'crowbar ' for the output side of my alternator but in the end i didn't use it. instead i made a warning light from a 2.2v  20ma. led, 3 resistors totaling 1700 ohms and a 13v zenor diode. at 14v it very faintly glows which is good to see that it is working. at 15.06 v it glows brightly. not much difference between 10ma. and 20ma. in brightness so i have some  leeway up to 30 volts. this warning is to protect 2 earthx batteries. whether or not i need it is a question but i gotta do something with that hole in the panel.

 EarthX battery BMS will protect the
 batteries. The BMS will not protect
 your avionics. If the BMS DISCONNECTS
 the battery from a runaway alternator,
 the bus voltage climbs at a VERY rapid
 rate.

 Unless your ov warning is BRIGHT, SUNLIGHT
 VIEWABLE, and FLASHES to trigger your
 Japanese kick boxer-reflexes . . . chances
 for making lots of transistor-toast is
 significant . . . but the batteries
 will be fine.



  Bob . . .



Virus-free. www.avast.com 3003266867060444899_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1" height="1">






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PostPosted: Mon Apr 01, 2019 6:28 am    Post subject: ov warning light Reply with quote

I'm not sure how to answer; your question seems to be changing with each post. Bob Nuckolls gave a pretty definitive answer to your original question. It then evolved to 'what is everyone else doing', to 'do alternators have built-in OV protection'. To answer the latest question: it's very unlikely that an alternator that was available for cars more than 10-15 years ago will have OV protection built in, but without mfgr specs, it's an unknown even with 'this year's model'. Newer cars tend to control *everything* with the car's computer, even voltage regulation is being done there on many cars now.
FWIW, using EarthX batteries without some form of OV protection to the system will just about guarantee that an OV event will fry all your other electronics. The EarthX will protect itself, and the resulting load dump will allow the OV to climb to dizzying heights almost instantly.
On Mon, Apr 1, 2019 at 8:55 AM bob noffs <icubob(at)gmail.com (icubob(at)gmail.com)> wrote:

Quote:
charlie, let's make the distinction between an ovm that is installed into the a/c system and the one that is supposedly in the alternator. i am sure some alternators have them but i have never seen any documentation about which alt. have it and how it is done.  bob noffs
On Mon, Apr 1, 2019 at 8:23 AM Charlie England <ceengland7(at)gmail.com (ceengland7(at)gmail.com)> wrote:

Quote:
OK, your answer illuminates the real question behind my half joking question: Who do you *trust* to answer your question? If your momma was like most, at some point she said something like, 
"If all your friends decided to jump off a cliff, would you do it too?"
I think from your answer you realize that most of the people you asked, had no idea what you were even talking about, much less were qualified to explain *why* they made the choice (because they never even made the choice). Obviously the guy with the 60A fuse had no clue. Not unlike the current crop of new parents, who read on Facebook that vaccinations might be dangerous, so now we've got outbreaks of measles and other really dangerous diseases putting others (who actually have good sense) at risk, and costing us millions in otherwise unnecessary health expenses.
Dimbulb governor

So really, shouldn't you be asking those who've had an OV event how their equipment fared, instead of asking those who've never needed one whether they have one? Or limit your ask to those who have the technical expertise to intelligently answer the question why they made their choice? I don't have one in my current RV-4, but it's a dirt simple day vfr a/c with mags firing the plugs, and the most expensive electrical item is the cheap, old comm in the panel. I'm just too busy and lazy to add OV protection to it. BUT: the RV-7 I'm building will have an electrically dependent engine with very expensive radios and instruments. You can bet that I already have OV protection built into both alternators on it.
Charlie
On Mon, Apr 1, 2019 at 7:37 AM bob noffs <icubob(at)gmail.com (icubob(at)gmail.com)> wrote:

Quote:
hi charlie,probably viewers of this forum have the highest % of using an ovm. of 10 people i have personally talked to no one has one. many believe that it is in their alternator which i think is true in some cases but who knows which ones. yesterday on a forum one person said he was protected by the 60 amp inline fuse on his alternator output.   i would be surprised if you said everyone you knew had one.
 bob noffs
On Sun, Mar 31, 2019 at 9:50 PM Charlie England <ceengland7(at)gmail.com (ceengland7(at)gmail.com)> wrote:

Quote:
Hi Bob,

Who are you asking? Smile

Charlie

On 3/31/2019 9:33 PM, bob noffs wrote:

Quote:
hi bob,  yea, i know. and all i am doing it for is the batteries. after asking a lot of questions about this over several months it seems hardly anyone is doing  anything to protect transistors. 
 bob noffs


On Sun, Mar 31, 2019 at 7:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
At 07:27 AM 3/31/2019, you wrote:
Quote:
--> AeroElectric-List message posted by: "bobnoffs" <icubob(at)gmail.com (icubob(at)gmail.com)>

hi all,
 i put together an ov'crowbar ' for the output side of my alternator but in the end i didn't use it. instead i made a warning light from a 2.2v  20ma. led, 3 resistors totaling 1700 ohms and a 13v zenor diode. at 14v it very faintly glows which is good to see that it is working. at 15.06 v it glows brightly. not much difference between 10ma. and 20ma. in brightness so i have some  leeway up to 30 volts. this warning is to protect 2 earthx batteries. whether or not i need it is a question but i gotta do something with that hole in the panel.

 EarthX battery BMS will protect the
 batteries. The BMS will not protect
 your avionics. If the BMS DISCONNECTS
 the battery from a runaway alternator,
 the bus voltage climbs at a VERY rapid
 rate.

 Unless your ov warning is BRIGHT, SUNLIGHT
 VIEWABLE, and FLASHES to trigger your
 Japanese kick boxer-reflexes . . . chances
 for making lots of transistor-toast is
 significant . . . but the batteries
 will be fine.



  Bob . . .



Virus-free. www.avast.com 3003266867060444899_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1" height="1">







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PostPosted: Mon Apr 01, 2019 7:43 am    Post subject: ov warning light Reply with quote

Whether over-voltage protection that is built into the alternator along side a regulator counts as over-voltage protection, is somewhat of an existential question.

All alternators with built in regulators have first-instance over-voltage protection, because that’s what the regulator does.

The reason to have additional over-voltage protection is to guard against a failure in the regulator. If your additional over-voltage protection is included in the same electronic and physical module as the regulator itself then in some sense it is now only part of the regulator.

You may then want yet another, external, over-voltage protection to protect against failure of the OVM in the regulator.

On Apr 1, 2019, at 9:48 AM, bob noffs <icubob(at)gmail.com> wrote:

charlie, let's make the distinction between an ovm that is installed into the a/c system and the one that is supposedly in the alternator. i am sure some alternators have them but i have never seen any documentation about which alt. have it and how it is done.
bob noffs

On Mon, Apr 1, 2019 at 8:23 AM Charlie England <ceengland7(at)gmail.com> wrote:
OK, your answer illuminates the real question behind my half joking question: Who do you *trust* to answer your question? If your momma was like most, at some point she said something like,
"If all your friends decided to jump off a cliff, would you do it too?"

I think from your answer you realize that most of the people you asked, had no idea what you were even talking about, much less were qualified to explain *why* they made the choice (because they never even made the choice). Obviously the guy with the 60A fuse had no clue. Not unlike the current crop of new parents, who read on Facebook that vaccinations might be dangerous, so now we've got outbreaks of measles and other really dangerous diseases putting others (who actually have good sense) at risk, and costing us millions in otherwise unnecessary health expenses.
Dimbulb governor

So really, shouldn't you be asking those who've had an OV event how their equipment fared, instead of asking those who've never needed one whether they have one? Or limit your ask to those who have the technical expertise to intelligently answer the question why they made their choice? I don't have one in my current RV-4, but it's a dirt simple day vfr a/c with mags firing the plugs, and the most expensive electrical item is the cheap, old comm in the panel. I'm just too busy and lazy to add OV protection to it. BUT: the RV-7 I'm building will have an electrically dependent engine with very expensive radios and instruments. You can bet that I already have OV protection built into both alternators on it.

Charlie

On Mon, Apr 1, 2019 at 7:37 AM bob noffs <icubob(at)gmail.com> wrote:
hi charlie,probably viewers of this forum have the highest % of using an ovm. of 10 people i have personally talked to no one has one. many believe that it is in their alternator which i think is true in some cases but who knows which ones. yesterday on a forum one person said he was protected by the 60 amp inline fuse on his alternator output.
i would be surprised if you said everyone you knew had one.
bob noffs

On Sun, Mar 31, 2019 at 9:50 PM Charlie England <ceengland7(at)gmail.com> wrote:
Hi Bob,

Who are you asking? Smile

Charlie

On 3/31/2019 9:33 PM, bob noffs wrote:
Quote:
hi bob,
yea, i know. and all i am doing it for is the batteries. after asking a lot of questions about this over several months it seems hardly anyone is doing anything to protect transistors.
bob noffs

On Sun, Mar 31, 2019 at 7:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com> wrote:
At 07:27 AM 3/31/2019, you wrote:
>
>
> hi all,
> i put together an ov'crowbar ' for the output side of my alternator but in the end i didn't use it. instead i made a warning light from a 2.2v 20ma. led, 3 resistors totaling 1700 ohms and a 13v zenor diode. at 14v it very faintly glows which is good to see that it is working. at 15.06 v it glows brightly. not much difference between 10ma. and 20ma. in brightness so i have some leeway up to 30 volts. this warning is to protect 2 earthx batteries. whether or not i need it is a question but i gotta do something with that hole in the panel.

EarthX battery BMS will protect the
batteries. The BMS will not protect
your avionics. If the BMS DISCONNECTS
the battery from a runaway alternator,
the bus voltage climbs at a VERY rapid
rate.

Unless your ov warning is BRIGHT, SUNLIGHT
VIEWABLE, and FLASHES to trigger your
Japanese kick boxer-reflexes . . . chances
for making lots of transistor-toast is
significant . . . but the batteries
will be fine.


Bob . . .



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PostPosted: Mon Apr 01, 2019 9:15 am    Post subject: ov warning light Reply with quote

At 07:30 AM 4/1/2019, you wrote:
Quote:
hi charlie,probably viewers of this forum have the highest % of using an ovm.

. . . why do you suppose that is?

Quote:
of 10 people i have personally talked to no one has one. many believe
that it is in their alternator which i think is true in some cases but
who knows which ones.

believing is not knowing, knowing is not
understanding . .

Quote:
yesterday on a forum one person said he was protected by the 60
amp inline fuse on his alternator output.

An alternator is incapable of opening its
own b-lead protection under ANY circumstances.
He is mistaken.

Quote:
i would be surprised if you said everyone you knew had one.

Me too . . . but then making good decisions
founded on lessons-learned and good science
are almost never made by taking a poll.



The reason this forum exists is to gather
and share the-best-we-know-how-to-do
based on understanding. If someone champions
a particular philosophy, he/she should be
capable of teaching it. Failing that,
the philosophy is suspect.

Just for grins, I checked out the latest
edition of 14CFR23 and got a surprise.
The 'bible' of small aircraft design
has be totally updated to a performance
based specification . . . almost zero
'hard' requirements for selection or
operation of components. For example,
here are the electrical system requirements
in their entirety:

23.2525 System power generation, storage, and distribution.
The power generation, storage, and distribution for any system must be
designed and installed to

(a) Supply the power required for operation of connected loads during all
intended operating conditions;

(b) Ensure no single failure or malfunction of any one power supply,
distribution system, or other utilization system will prevent the system from
supplying the essential loads required for continued safe flight and landing;
and

(c) Have enough capacity, if the primary source fails, to supply essential
loads, including non-continuous essential loads for the time needed to
complete the function required for continued safe flight and landing.

None of the above negates or replaces legacy
design goals for minimizing risk but it
does open doors for creative/innovative
designs. The downside is that the applicant
must produce volumes of justification for their
proposed design. The task can become a snarl
of snakes when BOTH contemporary authors and
reviewers of the written word are 'graduates' of
modern school systems.

My last tour of duty with a TC aviation
design and certification effort demonstrated
this condition in spades . . .

For our purposes, 23.2525(B) says it all.
If anyone proposes that timely, automatic
ov protection is not necessary, then
JUSTIFY that assertion with a lucid and
experimentally verifiable narration.

Back when my jobs were really fun, I
had to stand in front of a committee
of my customers and peers to pitch a
proposal. This COULD be a harrowing
experience but it was never a 'bad'
one. You either (a) came out with a
validation of your art and science or
(b) a bad idea was prevented from going
to production. This was a Win-Win
either way.

I captured the latest-n-greatest
14CFR23 for those who are interested . . .

https://tinyurl.com/y4y9qotk




Bob . . .


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bobnoffs



Joined: 04 Jul 2012
Posts: 99
Location: northern wi.

PostPosted: Mon Apr 01, 2019 11:16 am    Post subject: ov warning light Reply with quote

hi all,  when i started this thread i didn't really have a question, more like an observation of  how little ov protection is understood and the  vast numbers of opinions of what is going on with an ov condition and what it takes to stop it. if i would ask one question which i think bob just answered it is '' can a modern alternator  create overvoltage that the alternators own circuitry cannot prevent, requiring disconnecting the p lead from the a/c system?''
  bob noffs
On Mon, Apr 1, 2019 at 12:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
At 07:30 AM 4/1/2019, you wrote:
Quote:
hi charlie,probably viewers of this forum have the highest % of using an ovm.

   . . . why do you suppose that is?

Quote:
of 10 people i have personally talked to no one has one. many believe
that it is in their alternator which i think is true in some cases but
who knows which ones.

  believing is not knowing, knowing is not
  understanding . .

Quote:
 yesterday on a forum one person said he was protected by the 60
 amp inline fuse on his alternator output.

  An alternator is incapable of opening its
  own b-lead protection under ANY circumstances.
  He is mistaken.

Quote:
  i would be surprised if you said everyone you knew had one.

  Me too . . . but then making good decisions
  founded on lessons-learned and good science
  are almost never made by taking a poll.

 

  The reason this forum exists is to gather
  and share the-best-we-know-how-to-do
  based on understanding. If someone champions
  a particular philosophy, he/she should be
  capable of teaching it. Failing that,
  the philosophy is suspect.

  Just for grins, I checked out the latest
  edition of 14CFR23 and got a surprise.
  The 'bible' of small aircraft design
  has be totally updated to a performance
  based specification . . . almost zero
  'hard' requirements for selection or
  operation of components. For example,
  here are the electrical system requirements
  in their entirety:

§23.2525 System power generation, storage, and distribution.
The power generation, storage, and distribution for any system must be
designed and installed to—

(a) Supply the power required for operation of connected loads during all
intended operating conditions;

(b) Ensure no single failure or malfunction of any one power supply,
distribution system, or other utilization system will prevent the system from
supplying the essential loads required for continued safe flight and landing;
and

(c) Have enough capacity, if the primary source fails, to supply essential
loads, including non-continuous essential loads for the time needed to
complete the function required for continued safe flight and landing.

  None of the above negates or replaces legacy
  design goals for minimizing risk but it
  does open doors for creative/innovative
  designs. The downside is that the applicant
  must produce volumes of justification for their
  proposed design. The task can become a snarl
  of snakes when BOTH contemporary authors and
  reviewers of the written word are 'graduates' of
  modern school systems.

  My last tour of duty with a TC aviation
  design and certification effort demonstrated
  this condition in spades . . .

  For our purposes, 23.2525(B) says it all.
  If anyone proposes that timely, automatic
  ov protection is not necessary, then
  JUSTIFY that assertion with a lucid and
  experimentally verifiable narration.

  Back when my jobs were really fun, I
  had to stand in front of a committee
  of my customers and peers to pitch a
  proposal. This COULD be a harrowing
  experience but it was never a 'bad'
  one. You either (a) came out with a
  validation of your art and science or
  (b) a bad idea was prevented from going
  to production. This was a Win-Win
  either way.

  I captured the latest-n-greatest
  14CFR23 for those who are interested . . .

https://tinyurl.com/y4y9qotk




  Bob . . .


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PostPosted: Mon Apr 01, 2019 12:52 pm    Post subject: ov warning light Reply with quote

Then yes, a modern alternator is quite capable of creating an overvoltage event that its own circuitry cannot prevent. As others have indicated, even if the alternator has 'built in' OV protection, that gives rise to the risk that the same fault that caused the OV condition could also take out the OV protection circuit. The rest of the answer depends on whether you have an internally or externally regulated alternator. Bob Nu. justifiably favors external regulation, and with that, you can simply interrupt the field voltage supply (5A CB). With internally regulated alts (my personal choice to 'compromise'),  you will need to interrupt the B lead, which requires a heavy duty relay/contactor.  The OV module can control that relay/contactor, again with a low current CB.

Charlie

On 4/1/2019 2:15 PM, bob noffs wrote:

Quote:
hi all,   when i started this thread i didn't really have a question, more like an observation of  how little ov protection is understood and the  vast numbers of opinions of what is going on with an ov condition and what it takes to stop it. if i would ask one question which i think bob just answered it is '' can a modern alternator  create overvoltage that the alternators own circuitry cannot prevent, requiring disconnecting the p lead from the a/c system?''
  bob noffs


On Mon, Apr 1, 2019 at 12:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
At 07:30 AM 4/1/2019, you wrote:
Quote:
hi charlie,probably viewers of this forum have the highest % of using an ovm.

   . . . why do you suppose that is?

Quote:
of 10 people i have personally talked to no one has one. many believe
that it is in their alternator which i think is true in some cases but
who knows which ones.

  believing is not knowing, knowing is not
  understanding . .

Quote:
 yesterday on a forum one person said he was protected by the 60
 amp inline fuse on his alternator output.

  An alternator is incapable of opening its
  own b-lead protection under ANY circumstances.
  He is mistaken.

Quote:
  i would be surprised if you said everyone you knew had one.

  Me too . . . but then making good decisions
  founded on lessons-learned and good science
  are almost never made by taking a poll.

 

  The reason this forum exists is to gather
  and share the-best-we-know-how-to-do
  based on understanding. If someone champions
  a particular philosophy, he/she should be
  capable of teaching it. Failing that,
  the philosophy is suspect.

  Just for grins, I checked out the latest
  edition of 14CFR23 and got a surprise.
  The 'bible' of small aircraft design
  has be totally updated to a performance
  based specification . . . almost zero
  'hard' requirements for selection or
  operation of components. For example,
  here are the electrical system requirements
  in their entirety:

§23.2525 System power generation, storage, and distribution.
The power generation, storage, and distribution for any system must be
designed and installed to—

(a) Supply the power required for operation of connected loads during all
intended operating conditions;

(b) Ensure no single failure or malfunction of any one power supply,
distribution system, or other utilization system will prevent the system from
supplying the essential loads required for continued safe flight and landing;
and

(c) Have enough capacity, if the primary source fails, to supply essential
loads, including non-continuous essential loads for the time needed to
complete the function required for continued safe flight and landing.

  None of the above negates or replaces legacy
  design goals for minimizing risk but it
  does open doors for creative/innovative
  designs. The downside is that the applicant
  must produce volumes of justification for their
  proposed design. The task can become a snarl
  of snakes when BOTH contemporary authors and
  reviewers of the written word are 'graduates' of
  modern school systems.

  My last tour of duty with a TC aviation
  design and certification effort demonstrated
  this condition in spades . . .

  For our purposes, 23.2525(B) says it all.
  If anyone proposes that timely, automatic
  ov protection is not necessary, then
  JUSTIFY that assertion with a lucid and
  experimentally verifiable narration.

  Back when my jobs were really fun, I
  had to stand in front of a committee
  of my customers and peers to pitch a
  proposal. This COULD be a harrowing
  experience but it was never a 'bad'
  one. You either (a) came out with a
  validation of your art and science or
  (b) a bad idea was prevented from going
  to production. This was a Win-Win
  either way.

  I captured the latest-n-greatest
  14CFR23 for those who are interested . . .

https://tinyurl.com/y4y9qotk




  Bob . . .


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PostPosted: Mon Apr 01, 2019 12:56 pm    Post subject: ov warning light Reply with quote

In the Klixon catalogue there are part codes for dual coil circuit breakers that can trip the main (B lead) breaker if the secondary coil senses an overvoltage (or current, depending on what part you buy).

For the life of me I can’t find anyone that stocks such a thing, but it would be a dead easy way to fit or retrofit OV protection - anyone interested in trying to get a bulk order together?


On Apr 1, 2019, at 4:51 PM, Charlie England <ceengland7(at)gmail.com> wrote:

Then yes, a modern alternator is quite capable of creating an overvoltage event that its own circuitry cannot prevent. As others have indicated, even if the alternator has 'built in' OV protection, that gives rise to the risk that the same fault that caused the OV condition could also take out the OV protection circuit. The rest of the answer depends on whether you have an internally or externally regulated alternator. Bob Nu. justifiably favors external regulation, and with that, you can simply interrupt the field voltage supply (5A CB). With internally regulated alts (my personal choice to 'compromise'), you will need to interrupt the B lead, which requires a heavy duty relay/contactor. The OV module can control that relay/contactor, again with a low current CB.

Charlie

On 4/1/2019 2:15 PM, bob noffs wrote:
Quote:
hi all,
when i started this thread i didn't really have a question, more like an observation of how little ov protection is understood and the vast numbers of opinions of what is going on with an ov condition and what it takes to stop it. if i would ask one question which i think bob just answered it is '' can a modern alternator create overvoltage that the alternators own circuitry cannot prevent, requiring disconnecting the p lead from the a/c system?''
bob noffs

On Mon, Apr 1, 2019 at 12:21 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com> wrote:
At 07:30 AM 4/1/2019, you wrote:
> hi charlie,probably viewers of this forum have the highest % of using an ovm.

. . . why do you suppose that is?

> of 10 people i have personally talked to no one has one. many believe
> that it is in their alternator which i think is true in some cases but
> who knows which ones.

believing is not knowing, knowing is not
understanding . .

> yesterday on a forum one person said he was protected by the 60
> amp inline fuse on his alternator output.

An alternator is incapable of opening its
own b-lead protection under ANY circumstances.
He is mistaken.

> Â i would be surprised if you said everyone you knew had one.

Me too . . . but then making good decisions
founded on lessons-learned and good science
are almost never made by taking a poll.



The reason this forum exists is to gather
and share the-best-we-know-how-to-do
based on understanding. If someone champions
a particular philosophy, he/she should be
capable of teaching it. Failing that,
the philosophy is suspect.

Just for grins, I checked out the latest
edition of 14CFR23 and got a surprise.
The 'bible' of small aircraft design
has be totally updated to a performance
based specification . . . almost zero
'hard' requirements for selection or
operation of components. For example,
here are the electrical system requirements
in their entirety:

§23.2525 System power generation, storage, and distribution.
The power generation, storage, and distribution for any system must be
designed and installed to—

(a) Supply the power required for operation of connected loads during all
intended operating conditions;

(b) Ensure no single failure or malfunction of any one power supply,
distribution system, or other utilization system will prevent the system from
supplying the essential loads required for continued safe flight and landing;
and

(c) Have enough capacity, if the primary source fails, to supply essential
loads, including non-continuous essential loads for the time needed to
complete the function required for continued safe flight and landing.

None of the above negates or replaces legacy
design goals for minimizing risk but it
does open doors for creative/innovative
designs. The downside is that the applicant
must produce volumes of justification for their
proposed design. The task can become a snarl
of snakes when BOTH contemporary authors and
reviewers of the written word are 'graduates' of
modern school systems.

My last tour of duty with a TC aviation
design and certification effort demonstrated
this condition in spades . . .

For our purposes, 23.2525(B) says it all.
If anyone proposes that timely, automatic
ov protection is not necessary, then
JUSTIFY that assertion with a lucid and
experimentally verifiable narration.

Back when my jobs were really fun, I
had to stand in front of a committee
of my customers and peers to pitch a
proposal. This COULD be a harrowing
experience but it was never a 'bad'
one. You either (a) came out with a
validation of your art and science or
(b) a bad idea was prevented from going
to production. This was a Win-Win
either way.

I captured the latest-n-greatest
14CFR23 for those who are interested . . .

https://tinyurl.com/y4y9qotk



Bob . . .



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PostPosted: Mon Apr 01, 2019 2:04 pm    Post subject: ov warning light Reply with quote

At 02:15 PM 4/1/2019, you wrote:
Quote:
hi all,
when i started this thread i didn't really have a question, more
like an observation of how little ov protection is understood and
the vast numbers of opinions of what is going on with an ov condition
and what it takes to stop it.

if i would ask one question which i think bob just answered it is
"can a modern alternator create overvoltage that the alternators
own circuitry cannot prevent, requiring disconnecting the p lead
from the a/c system?"

Due diligence to the doctrine of FMEA
dictates that we ASSUME that such
a failure can occur. Intuitively,
we can deduce that a piece of electronics
with LOTS of parts and total control
over field voltage could step in
a gopher hole and light off a bad day
in the cockpit.

The condition applies irrespective of whether
the regulator is internal or external
to the alternator. Independent ov protection
is indicated even when the alternator's
advertising literature calls out some
kind of ov protection. This is
necessary because lacking specific
data for how the stock regulator
accomplishes ov protection, we
cannot know that it's independent
of voltage regulation tasks.

When we built ov protection into the
B&C products, ov/lv monitoring
and management was totally independent
of voltage regulation. Since we
designed it, we KNEW that independence
was built in.

To be sure, built in regulators
ARE quite reliable. Failure rates
are low. But if stock internal
regulators had the kind of reliability
demanded by air-transport certification
standards, then there wouldn't be
so many of the things offered as
spares!

https://tinyurl.com/yxtogftx

The best way to bring a runaway
alternator to heal is open the FIELD
supply path. B&C and PlanePower
products modify stock automotive
products to implement EXTERNAL
control of field supply. This
gives the panel mounted alternator
switch absolute control over
alternator output while providing
a place to apply low-current
ov protection as well.

Breaking the b-lead per Z-24
will get 'er done but it's not
preferred. Doing the mod to
incorporate external regulation
and ov management is not difficult.





Bob . . .


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PostPosted: Mon Apr 01, 2019 2:20 pm    Post subject: ov warning light Reply with quote

At 03:55 PM 4/1/2019, you wrote:
Quote:
--> AeroElectric-List message posted by: Alec Myers <alec(at)alecmyers.com>

In the Klixon catalogue there are part codes for dual coil circuit breakers that can trip the main (B lead) breaker if the secondary coil senses an overvoltage (or current, depending on what part you buy).

For the life of me I can’t find anyone that stocks such a thing, but it would be a dead easy way to fit or retrofit OV protection - anyone interested in trying to get a bulk order together

I recall seeing these things in some
catalogs wayyyy back when but one look
at the price and the bloom-was-off-the-
rose as they say.

The really cool way to open the b-lead
is with a processor controlled contactor
in series with b-lead paired with a big-momma-FET
in parallel with the b-lead. You drop
the coil current on the contactor some
interval of time before you energize
the FET to put a dead short on the alternator
B-lead. This 'crowbars' the b-lead to
ground and deprives the field supply
of its power source. The 'spike' in the
FET is only slightly greater than the
alternator's output rating and lasts
for micro-seconds.

After the alternator is brought to
heel, current flowing in the shunt
FET is just a couple of amps generated
by residual field flux.




Bob . . .


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PostPosted: Mon Apr 01, 2019 2:23 pm    Post subject: ov warning light Reply with quote

Quote:
The really cool way to open the b-lead
is with a processor controlled contactor
in series with b-lead paired with a big-momma-FET
in parallel with the b-lead. You drop
the coil current on the contactor some
interval of time before you energize
the FET to put a dead short on the alternator
B-lead. This 'crowbars' the b-lead to
ground and deprives the field supply
of its power source. The 'spike' in the
FET is only slightly greater than the
alternator's output rating and lasts
for micro-seconds.

After the alternator is brought to
heel, current flowing in the shunt
FET is just a couple of amps generated
by residual field flux.

See https://tinyurl.com/mucjhgs



Bob . . .


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kenryan



Joined: 20 Oct 2009
Posts: 344

PostPosted: Mon Apr 01, 2019 3:19 pm    Post subject: ov warning light Reply with quote

Bob said "Breaking the b-lead per Z-24 will get 'er done but it's not preferred."My question is WHY if opening the b-lead will work, it is "not preferred."
On Mon, Apr 1, 2019 at 2:27 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

Quote:
Quote:
 The really cool way to open the b-lead
 is with a processor controlled contactor
 in series with b-lead paired with a big-momma-FET
 in parallel with the b-lead. You drop
 the coil current on the contactor some
 interval of time before you energize
 the FET to put a dead short on the alternator
 B-lead. This 'crowbars' the b-lead to
 ground and deprives the field supply
 of its power source. The 'spike' in the
 FET is only slightly greater than the
 alternator's output rating and lasts
 for micro-seconds.

 After the alternator is brought to
 heel, current flowing in the shunt
 FET is just a couple of amps generated
 by residual field flux.

  See https://tinyurl.com/mucjhgs



  Bob . . .


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PostPosted: Mon Apr 01, 2019 3:45 pm    Post subject: ov warning light Reply with quote

Shorting the B-lead through a FET is also going to pull the main bus to zero, as well as the battery, no?
On Apr 1, 2019, at 6:22 PM, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com> wrote:

Quote:
The really cool way to open the b-lead
is with a processor controlled contactor
in series with b-lead paired with a big-momma-FET
in parallel with the b-lead. You drop
the coil current on the contactor some
interval of time before you energize
the FET to put a dead short on the alternator
B-lead. This 'crowbars' the b-lead to
ground and deprives the field supply
of its power source. The 'spike' in the
FET is only slightly greater than the
alternator's output rating and lasts
for micro-seconds.

After the alternator is brought to
heel, current flowing in the shunt
FET is just a couple of amps generated
by residual field flux.

See https://tinyurl.com/mucjhgs
Bob . . .


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user9253



Joined: 28 Mar 2008
Posts: 1452
Location: Riley TWP Michigan

PostPosted: Mon Apr 01, 2019 3:46 pm    Post subject: Re: ov warning light Reply with quote

Quote:
"My question is WHY if opening the b-lead will work, it is "not preferred."
Because the B-Lead current is 10 times the field current. Heavy current will require a heavy duty relay or contactor.
Field current can be interrupted with a small relay or circuit breaker along with solid state components


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kenryan



Joined: 20 Oct 2009
Posts: 344

PostPosted: Mon Apr 01, 2019 4:03 pm    Post subject: ov warning light Reply with quote

Thanks 

Sent from my Android. Sorry Steve.
On Mon, Apr 1, 2019, 15:51 user9253 <fransew(at)gmail.com (fransew(at)gmail.com)> wrote:

Quote:
--> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com (fransew(at)gmail.com)>


> "My question is WHY if opening the b-lead will work, it is "not preferred."
 Because the B-Lead current is 10 times the field current.  Heavy current will require a heavy duty relay or contactor.
Field current can be interrupted with a small relay or circuit breaker along with solid state components

--------
Joe Gores




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