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Auto Alternators

Looking at the link for the alternator used by Bob it seems pretty clear that the B&C alternator is from the Denso stable - just have to find the particular model number for the equivelent part. Now have to also track down the regulator and see if there is an equivelent version of the regulator with overvoltage protection. Objective here is to find alternative sources for alternators and regulators for field replacement/repairs.
KT

Buy the Amazon alternator, add Perihelion or other OVP protection device, done. No need to overthink this.
 
Hard Facts

Looking at the link for the alternator used by Bob it seems pretty clear that the B&C alternator is from the Denso stable - just have to find the particular model number for the equivelent part. Now have to also track down the regulator and see if there is an equivelent version of the regulator with overvoltage protection. Objective here is to find alternative sources for alternators and regulators for field replacement/repairs.
KT

Someone is just going to have to take the B&C apart to know what is in it. And . . that will not track future production changes.

Looking at the outside and getting the lester number does not define the guts. The bearings can be different, the items like brush holders, and connector sockets can also be special. The "fit" is common, but not the internal wire connections. I have attempted to do this externally for the commercial equal of the PP, and have yet to find one. The internals match the fit, but not the precise function.

Regarding the backup, what is the likely failure mode? Wear parts, electronics, electrical, bearings? Carry them all? I would not dare expect to be able to properly replace parts on the ramp with a handful of tools. All that would be more weight than a spare alternator.

Why not just run the B&C for 500 hrs, then check the bearings, brushes every 100 hrs? Then replace it at 1000 hrs (or XXXXhrs). A PP 60A is 6.5 lbs. It seems there are many better options to improve the odds than carrying parts. Having the B&C is a really good baseline, and they will rebuild it, right?

Carefully define your expectations and failure scenarios , share if you will, and look at what situation/problem is being solved. Problem, action, result.

This may sound negative, but I have stepped though each scenario and been doing the homework on the PP 60A, and asked myself all the same questions. My friends PP has 450 hrs, Joes failed at 510, but it was a bridge, and repaired. It is a good design. Not without some production issues in the past. Warranty is a 1000 hrs.

We could write a book on this but who would read it?
 
Looking at the link for the alternator used by Bob it seems pretty clear that the B&C alternator is from the Denso stable - just have to find the particular model number for the equivalent part. Now have to also track down the regulator and see if there is an equivelent version of the regulator with overvoltage protection. Objective here is to find alternative sources for alternators and regulators for field replacement/repairs.
KT
B&C's claim to fame with their (ND based) alternators (besides high price $550 for alt + regulator) are two fold: 1) They are externally regulated with a "crow bar"; 2) They are reported to be "blue printed", hand fitted, balanced, blessed by tibetan monks....(OK made the last part up). How they modify it off the shelf parts verses in-house made parts maybe, who knows.

I do know if your exhaust is 1 inch away and your engine/prop shakes like a wet dog getting out of a bath, your alternator will fail earlier.

People have had B&C parts fail, like the VR. The external regulator I looked at 10 years ago was hobby quality (good but something you can make if you own a solder iron). It was in a hobby case, hand soldered discreet components with a TO-3 transistor externally mounted. It may have changed. The circuitry of a voltage regulator is simple, and to incorporate an OV crow bar in the VR is also simple. The crow bar is a well known design as old as the hills and a very simple circuit. Anyone with a basic understanding of electronics can figure it out. There are more advanced external VR's in marine and commercial vehicle industry that do all kinds of cool tricks, including OV and changeable voltage schedules.
 
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Designing for maintainability

Part of my strategy for figuring out what I have actually purchased with the B&C alternators and regulators, besides being curious about the actual quality of the parts is to be able to figure out a ?what if? strategy for dealing with component failures when on a long cross country. Having the capability to order parts through a local NAPA store is a big plus (especially when you know the part number and know it is going to work) and doing the work to figure out what to order ahead of time adds to peace of mind. A secondary issue is figuring out what value is added by buying from B&C for the substantial differential in cost compared to buying new OEM from a Denso supply house. I would hope that B&C have the capability to do a quality professional engineering job rather than just adding torqueseal and their own label to second sourced components. I dont see the evidence for making any positive judgement in that area. I would be inclined to believe that new OEM parts would have lower failure rates and be better value than rebuilt second sourced parts (even if they have been blessed by religious monks).
KT
 
B&C Regulator

After reading the post from GMCjet pilot and being curious about the quality of the construction of the regulator and realizing it was in a Radio Shack hobby diecast box I decided to cast caution to the wind and take the cover off to inspect the hidden stuff. The screws securing the cover were cemented in place so they needed the heads drilled out to remove the lid. The circuit board is attached to the lid so it came apart without damage once the screw heads were removed. The circuit board is double sided with plated through holes. All components are hand soldered and typical commercial components for circa 1990?s designed electronics. Some parts ( capacitors and plastic case transistors) had strands of rubber cement like material spread across them to provide some level of protection against vibration. There were areas where solder flux had not been cleaned off after the soldering operation and no areas where conformal coating had been applied. No quite what I was expecting for aircraft quality stuff. The circuit board silk screening had revision letter G with a date of 1996. Seemed to fit with my recollection of 1990 style hand soldered boards. Will probably just clean off the residue of solder flux apply some conformal coat material and more vibration damping in the appropriate areas, reassemble and use until it fails and then go to plan B.
KT
 
B&C Regulator Reverse Engineering

Ed,
I don?t think that taking and posting pictures and doing any published reverse engineering on the B&C regulator is a good or ethical idea. The required regulator circuit is published in many places on the web. The implementation for an OVP circuit is likewise also available. B&C may be overpriced with quality that has considerable room for improvement. Clearly it is not up to TSO/PMA standards but they did the design,development and manufacturing and are providing a warranty (which I have now invalidated) and customer support. I took this unit apart to satisfy my own peace of mind for my safety and the passengers that fly with me. I may trace out the circuit and review the component rating to determine the derating margins but that would be the extent of any engineering I would do. Knowing what I know now I would look further into the Perihelion unit which, by the way is approved by the UK Light Airplane Association. The LAA approval process is apparently much closer to TSO/PMA approval so I have been told.
KT
 
Ed,
I don’t think that taking and posting pictures and doing any published reverse engineering on the B&C regulator is a good or ethical idea. The required regulator circuit is published in many places on the web. The implementation for an OVP circuit is likewise also available. B&C may be overpriced with quality that has considerable room for improvement. Clearly it is not up to TSO/PMA standards but they did the design,development and manufacturing and are providing a warranty (which I have now invalidated) and customer support. I took this unit apart to satisfy my own peace of mind for my safety and the passengers that fly with me. I may trace out the circuit and review the component rating to determine the derating margins but that would be the extent of any engineering I would do. Knowing what I know now I would look further into the Perihelion unit which, by the way is approved by the UK Light Airplane Association. The LAA approval process is apparently much closer to TSO/PMA approval so I have been told.
KT
This design is not "rocket surgery or brain science" (joke). Google voltage regulator circuit... B&C copied this circuit. To copy this circuit is like copying the wheel of electronics. TSO/PMA is not a patent or copy-write. People can copy any TSO/PMA but have to go through the regulatory hoops. You could not get a patent on this, too basic.

Save yourself the trouble, buy a modern VR. Google: "Transpo V1200 voltage regulator", for about $60 (B&C = $180).

31eG6paZgiL._AC_.jpg


V1200 - Voltage Regulator, 12 Volt, B-Circuit, 14.2 Volt Set Point, For Universal Applications

Notes:
For version with Ford style narrow blade terminals to fit OE Ford regulator plug use V1200F.
For version with under voltage warning light us V1300.
For 24 volt version use V2400.
Terminal Identification: L-B+-STATOR-FLD-GND Terminals

Features:
Voyager Series Regulator
Adjustable voltage (13.0-16.0V)
Precise digital* regulation
Short-circuit protected
High current capability
Over voltage protection

Ignition or light circuit activated with high side regulation (B-circuit)
Protected against loss of ground and under voltage
LED's for easy troubleshooting
Fault detection indicators

Item Weight 9.6 ounces
Package Dimensions 4.8 x 3.6 x 1.8 inches


* Not sure what is "digital". Voltage Regulation is basic analog feedback. I don't see a need for digital.
They my be using the term digital for PWM (pulse width modulation) or have a chip in it for fault logic?
Regardless of "digital" hype this VR does more than the B&C for 1/3rd the price.

https://store.alternatorparts.com/v1200-voltage-regulator-circuit-14-for-universal-applications.aspx

https://www.amazon.com/NEW-Adjustable-Voltage-Regulator-V1200/dp/B00OBTI5Q2
 
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In reply to the previous post.
Having been in the Aerospace electronics design business in a previous life and seen a lot of equipment into service on large commercial aircraft and a range of military and commercial projects I have an opinion about the ease of building and developing your own regulator. Understating the significance of doing robust, complete design, development, production engineering, testing and qualification of a product being brought to market where performance and reliability in a harsh environment is required is often trivialized by those without the scars from having done it. The devil as always is in the details. A seeming trivial example is changing solder composition and the flux and degreasing process to meet modern environmental standards. Even with the best circuit design , board layout, pick and place machines and component selections reliability will be poor if the new processes are incompatible or not fully tested. There really is a lot more than just throwing a few parts together. Using a regulator that is untested in the application, requires development testing and possible modification will quickly suck up the $100 difference in cost (even you only charge your time at $5 per hour) unless the plan is to amortize over a number of units or you are doing it for the? learning? experience.
B&C has a good reputation with the alternators and regulators that they produce even if the products were developed many years ago. Are they likely to be as reliable as modern surface mount machine assembled boards with IR reflow soldering - almost certainly not. But until a suitable candidate is identified, evaluated, examined and tested to qualification levels, the B&C offering may be the best overall solution if the objective is to finish and fly your airplane project.
KT
 
While there seems to be widespread acceptance of using external regulators here on VAF, I'm going to stay with my genuine Denso IR alternator given that they haven't used external regs for about 3 decades now in cars and I have around 35,000+ hours personally on them with zero failures except for brushes wearing down to nothing after something like 5000 hours on one of them after 20 years of use.

I also used to own an auto repair shop in the past, with most customers driving Toyotas equipped ND alternators. Never saw a regulator failure on those hundreds of vehicles either.

Denso puts tens of millions into research, QC and testing their alternators and they are the #1 choice in the world for top auto brands with hundreds of millions of units made. They can't afford reg failures in modern cars loaded with electronics.

If Denso thought external regs were more reliable, they'd still be using them.

I don't buy the fact that some low volume, relatively untested external reg is more reliable than what ND offers.

Alternator brands made for aircraft which are sometimes failing in 25-100 hours are clearly not well designed or well made when modern ND alternators frequently exceed 5000 hours with zero maintenance in that time.
 
While there seems to be widespread acceptance of using external regulators here on VAF, I'm going to stay with my genuine Denso IR alternator given that they haven't used external regs for about 3 decades now in cars and I have around 35,000+ hours personally on them with zero failures except for brushes wearing down to nothing after something like 5000 hours on one of them after 20 years of use.....
Agree, but some people are heck bent on external VR's. The B&C external regulator is not really anything to justify a $180 price tag. I am running Denso IR Alternator.
 
In addition all the correct reasoning Ross mentions, just want to add there is an additional very good reason why the regulator should be mounted on the alternator itself: to thermally sense the alternator. Internally regulated alternators limit current output when the alternator gets hot to prevent damage to the alternator. An acquaintance of mine was on the engineering team that developed the first IR regulator for GM in the 70's and cited this reason for the change, in addition to lowering the parts count.
 
Here?s a question then... since it seems auto alternators are generally a viable solution for belt-driven applications... what about accessory pad alternators? Are there automotive alternatives or are we stuck paying the airplane tax for the fancy case and gear drive?
 
Any easy primer on going with a small IR alternator from a 14129 type Denso and a Ford type regulator?

Mine is the Zeftronics with internal OV relay, so I assume the Perhelion replacement and current switch (off down, batt center Alt field on up) and field 5 amp circuit breaker all stay?
 
Save yourself the trouble, buy a modern VR. Google: "Transpo V1200 voltage regulator", for about $60 (B&C = $180).

31eG6paZgiL._AC_.jpg


V1200 - Voltage Regulator, 12 Volt, B-Circuit, 14.2 Volt Set Point, For Universal Applications

I really like the idea of this regulator paired with the Dodge Van alternator.

Bob Nuckolls' comment on it was that the design of its overvoltage monitor are unknown. He said some just illuminate a light, and thats it. Wondering if anyone has dissected one of these to find out how they are designed, or tested them out. Anyone ever heard of a failure of this regulator?
 
Alternator Alternatives?

I'm trying to find an alternator for my 6 hoping to find an option where I can just walk in and find one in stock. I'm replacing a Duralast 14184, 70s & early 80s Honda. Any ideas? ANOTHER question... Is rotation direction really an issue? I've read the only difference is the cooling fan blades which I am hoping isn't an issue with direct-blow cooling (would remove fan blades anyway). Thoughts?
 
Alternator reliability

Generally agree with Ross?s comments. Denso has the best reputation for performance and reliability and I could well imagine that they spent big bucks on their development and CQI (continuous quality improvement) programs. Putting the regulator in the alternator does have advantages from a production viewpoint (lower parts count, big reduction in wiring, easier troubleshooting and service replacement among others) but the same quality of regulator remotely mounted out of the vibration and temperature cycling and peak temperature environment will be more reliable. So from a design viewpoint if the failure rate of the alternator is equally balanced between the electronics and the rotating components and both are going to make the useful lifetime of the vehicle design, objectives have been met - and that is where Denso seems to be. They have the weight of very high production volumes pushing them to stay on the pinnacle of design and production excellence. I looked for a spline driven equivalent to the B&C but have not found one. Suspect the only options for the spline drive alt have an airplane price and need an external regulator.

KT
 
While there seems to be widespread acceptance of using external regulators here on VAF, I'm going to stay with my genuine Denso IR alternator given that they haven't used external regs for about 3 decades now in cars and I have around 35,000+ hours personally on them with zero failures except for brushes wearing down to nothing after something like 5000 hours on one of them after 20 years of use.

I also used to own an auto repair shop in the past, with most customers driving Toyotas equipped ND alternators. Never saw a regulator failure on those hundreds of vehicles either.

Denso puts tens of millions into research, QC and testing their alternators and they are the #1 choice in the world for top auto brands with hundreds of millions of units made. They can't afford reg failures in modern cars loaded with electronics.

If Denso thought external regs were more reliable, they'd still be using them.

I don't buy the fact that some low volume, relatively untested external reg is more reliable than what ND offers.

Alternator brands made for aircraft which are sometimes failing in 25-100 hours are clearly not well designed or well made when modern ND alternators frequently exceed 5000 hours with zero maintenance in that time.

While I agree that the quality of the VR is far more important than where it is placed, the challenge is that this removes almost all less expensive, rebuilt alternators. The rebuild process likely removes the OEM VR and replace it with a cheap aftermarket VR.

Any ideas where we can find affordable, ORIGINAL ND alternators or factory rebuilts? Especially in the smaller case sizes.

Larry
 
I'm trying to find an alternator for my 6 hoping to find an option where I can just walk in and find one in stock. I'm replacing a Duralast 14184, 70s & early 80s Honda. Any ideas? ANOTHER question... Is rotation direction really an issue? I've read the only difference is the cooling fan blades which I am hoping isn't an issue with direct-blow cooling (would remove fan blades anyway). Thoughts?

Unlikely you will find an externally regulated alternator in stock, been many years since external regulators were in common use. The 14184 is a good alternator....buy an extra if you are concerned about supply.....they are inexpensive. I keep a spare in the hangar.
 
I really like the idea of this regulator paired with the Dodge Van alternator.

Bob Nuckolls' comment on it was that the design of its overvoltage monitor are unknown. He said some just illuminate a light, and thats it. Wondering if anyone has dissected one of these to find out how they are designed, or tested them out. Anyone ever heard of a failure of this regulator?
Bob is saying he does not know. He's not an engineer and anything he does not understand is suspect. That is not a bad thing per se. His philosophy and opinions are rooted in thinking of simple discrete components as best. He is a dogmatic proponent that only externally regulated alternators should go in airplanes. I once suggested to Bob years ago internal VR's are reliable and I was an engineer. He did not take that well. He made his point by calling engineers idiots. With respect Bob does not know what engineers do.

I'm not selling the V1200 regulator but others have had good experiance with it. Because it is potted it would be difficult to look at it. Why do you suspect it, because Bob threw shade on it. Again Bob has very strong opinions and basically endorses B$C. Bob will also insist on reliability data. If you ask for his data you get crickets. Internal VR alternators have combined reliable operational hours in cars, trucks and industrial equipment that are unmatched. I had two Acura's I drove for decades before selling with over 200K miles, with their original internal ND alternators. ND internally regulated alternators in planes also have excellent service history. Up to you.

B&C VR is simple, with a basic crow bar made with basic electronic fabrication methods. If you don't know a crow bar is a dead short on the field power that blows a fuse to protect the circuit. Crow bar is like a literal metal crow bar thrown from hot side to ground, dead short. It's a very basic well known circuit. Does it work? Sure, for $180 and subject to failure like anything. Crow bars can be reset, some can't. If your crow bar uses a one and done fuse, you have to replace the fuse.

The Transpo has OV protection not just lights, which frankly is more elegant IMHO. It likely uses a very basic off the shelf IC chip for voltage monitoring you can buy from Digikey or Mouser. A similar IC is used in ND internal VR's. It simply opens up the circuit (solid state switching or relay) to the field verses shorting it out and blowing a fuse. You can add a crow bar and fuse to any external VR. It's not necessary on V1200.

Keep in mind Bob comes from the day when all alternators were externally regulated and All VR's were mechanical.... there were lots of OV events in those days cars and GA planes. Not saying Bob is a luddite but he is set in his ways. You can't go totally wrong with his opinion, I just respectfully disagree. We can trust modern IC circuits be it internal VR or a Transpo V1200 as much as the 1970's technology B&C sells.

Last external VR mounted in lwr vibration lwr heat area makes sense. However modern electronics designed for vibs and heat are reliable even in severe environments. However keep your engine/prop balanced and shield alternator from heat. Not hard thing to do, and you'll be reward with a long lived alternator.

PS Congrats to Bob Nuckolls for his recent induction to an aviation hall of fame for his contrabutions. He definitely influanced many kit plane builders.
 
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While I agree that the quality of the VR is far more important than where it is placed, the challenge is that this removes almost all less expensive, rebuilt alternators. The rebuild process likely removes the OEM VR and replace it with a cheap aftermarket VR.

Any ideas where we can find affordable, ORIGINAL ND alternators or factory rebuilts? Especially in the smaller case sizes.

Larry

I've listed genuine ND sources in the US before in these threads and just recently here, an ND source link searchable by state.

My point has always been to use new genuine ND alternators or ones remanufactured by ND affiliates which only use genuine ND parts inside as new. Anything else is an unknown.
 
George makes some great points in his post above. I too, am not really a fan of many of Bob Nuckolls' ideas and people often ask us to comment on such and such circuit or schematic based on Bob's ideas for basic power when using our EFI/EI products. We generally don't. We have our own recommendations based on our 25 years in this field supplying over 10,000 digital controllers should you find that useful.

I believe George is correct in saying that Bob's views and opinions have shaped this external regulator idea in the Experimental world greatly. The bottom line is do you trust the demonstrated reliability of the largest alternator manufacturer in the world with billions of hours of real world use over 40+ years and their tremendous engineering and testing resources or those of an individual with neither who bases his views on 1970s technology?
 
I recently converted my perfectly functional ND alternator to external regulation after following every alternator thread I could find. I originally believed that the integrated ND regulator to be bulletproof and after gutting one to convert to the external regulation I'm even more convinced. As I ripped the guts out of this well potted, tiny board brimming with SMDs and replaced it all with some blobs of solder and lengths of copper wire I couldn't help thinking I just took a huge step backwards in reliability.

That said, I took that step backwards to protect against the one failure mode that the IR can't protect against - over voltage. I'm now electrically dependant and an overvoltage event will turn me into a glider in a split second. Yes, its unlikely that the IR will fail in the first place, but if it does go rouge, I can't expect that same misbehaving device to shut off power to the field. An externally regulated alternator has a physical hard wire to the field windings that if disconnected will absolutely shut down the alternator.

I looked at some brute force options like a transorb diode on the alternator output, but that would require a relay and a big CB. By the time you trip the chain of components and get the crowbar action, enough stray voltage my have made it to the ECU.

If anyone knows of a super fast acting device with enough capacity to cut off the snake's head before it strikes, I'm all ears. I'd go back to the IR Denso unit in a second.
 
We have our own recommendations based on our 25 years in this field supplying over 10,000 digital controllers should you find that useful.

I believe George is correct in saying that Bob's views and opinions have shaped this external regulator idea in the Experimental world greatly. The bottom line is do you trust the demonstrated reliability of the largest alternator manufacturer in the world with billions of hours of real world use over 40+ years and their tremendous engineering and testing resources or those of an individual with neither who bases his views on 1970s technology?

I love Japanese engines, in my cars, but put one in my aircraft... no thanks.
I don't care how many millions of miles my Honda with an ND alternator goes, it's not the same thing, so that comparison is irrelevant.

And I doubt you have 10,000 controllers flying either, so that is also a meaningless number as it pertains to aircraft reliability.

I'm pretty sure the consensus on alternator reliability the clear winner is always B&C, show me some 'aircraft' reliability numbers to the contrary and I'll think about switching.
 
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Alternator Failures and Failure Rates

Back in the last century as a young engineer working on a digital engine and flight control program an aspect of the development was installing the instrumented digital computer units on a couple of in service commercial aircraft flying regular scheduled airline routes just to ride the environment. The test units tapped into the aircraft sensors and had dummy loads for the actuators so not only could the temperature and vibration environment be monitored but when failures occurred (and they did) the response of the digital units could be observed. The units were not controlling any aircraft functions.A number of different locations on engines and air frames were chosen so that a wide range of data collected could be correlated to confirm basic assumptions, digital control technology and the electronics packaging of the day.
A lot was learned over thousands of flight hours. Location, attachment, vibration, cooling and temperature variation and temperature ranges really matters. If you are familiar with Minors Law for low cycle fatigue then you would not be surprised that the results follow the same trends. Trying to correlate the performance of an IR alternator designed for a mostly low power liquid cooled automobile engine with the same alternator installed on a large bore air cooled high power aircraft engine has a fundamental problem. In addition the failure modes may not correlate. Latent faults followed by a second more significant fault may result in exposure to an overvoltage fault that is not suppressed. These types of faults may not manifest in the automobile application due to lower vibration, smaller and less significant temperature cycles etc. and the only way to determine the likely outcome is to measure the temperature and vibration profiles to do the accelerated testing schedules. The alternator has access to a lot of energy through its connection to the engine - having a hardover field connection to the 12+ supply will cause the alternator to couple to every last watt that is available from the engine with the high probability of a fire and blown up electronics. So this is not a trivial problem where the right answer is obvious.

KT
 
We've recommended an automatic voltage limiting system in aircraft when using our EFI systems for a while now, it's certainly a good idea.

We've sold over 10,000 controllers now, 2000 have been fitted to aircraft, the other 8000 primarily in cars and boats. We believe these have collectively accumulated something over 20 million hours. I've never got one back for warranty which has been fried by OV on the input. The aircraft units have something over 650,000 flight hours on them we estimate.

This tells me that OV events are either very rare or don't reach levels which would fry our boards.

Our older units were tested to 20 volts, newer designs to 30 volts. I don't know what it would take to actually damage them.

The CPI-2 has an internal crowbar system and an isolated backup battery which is automatically switched over to in the event of OV or UV.

Now we have seen here on VAF, many of one brand alternator fail in only tens or maybe a couple hundred hours but people keep buying and using them. I know I wouldn't be, but to each their own.

We can talk about vibration levels being higher on a Lycoming than a typical automotive engine, yes I agree, generally true. Temperatures, probably not. I've measured after shutdown, under hood temps on one of my turbocharged cars at over 320F. That alternator went over 6000 hours before the brushes wore out on a very shaky, big four. I doubt if it gets that hot on a Lyc outside of the baffling after shutdown (but it would be interesting to measure).

In our experience with fully potted boards, they never have vibration failures. How could they? Nothing can move. Hard connections can fail, flexible connection can fail, I've seen that happen many times on many electrical things in aircraft and cars over time.

I know we have several folks on here flying OEM IR Denso alternators with over 1500 hours on them. That's a good deal better than what many report with the one brand.
 
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Quote: We can talk about vibration levels being higher on a Lycoming than a typical automotive engine, yes I agree, generally true. Temperatures, probably not. I've measured after shutdown, under hood temps on one of my turbocharged cars at over 320F. That alternator went over 6000 hours before the brushes wore out on a very shaky, big four. I doubt if it gets that hot on a Lyc outside of the baffling after shutdown (but it would be interesting to measure).

In our experience with fully potted boards, they never have vibration failures. How could they? Nothing can move. Hard connections can fail, flexible connection can fail, I've seen that happen many times on many electrical things in aircraft and cars over time.

I know we have several folks on here flying OEM IR Denso alternators with over 1500 hours on them. That's a good deal better than what many report with the one brand.[/QUOTE]

Having taken the potted regulator apart from a Rotax In a RV-12 and carefully picked all the potting apart to get down to the circuit board and draw out the circuit there were a number of conclusions.
The electronic design used power components that were poorly suited to the application resulting in higher than necessary power dissipation in the regulator.
The mechanical and thermal design was inadequate resulting in repeated thermal mechanical stress which had caused solder joints to fail. The potting did nothing to solve the repeated temperature cycling problem (probably made it worse). The potting certainly made it more difficult to do the investigation. The conclusion is that potting may be a good thing to avoid moisture, contamination, broken component leads for non surface mount components but it isnt going to prop up a basically poor mechanical/thermal design. The Ducati regulator is not quality engineering on a number of levels and deservedly has a poor reputation. It should noted that the Rotax generator is a permanent magnet generator with no field control and works on a different principle than the alternators being discussed in this thread.
KT
 
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Having taken the potted regulator apart from a Rotax In a RV-12 and carefully picked all the potting apart to get down to the circuit board and draw out the circuit there were a number of conclusions.
The electronic design used power components that were poorly suited to the application resulting in higher than necessary power dissipation in the regulator.
The mechanical and thermal design was inadequate resulting in repeated thermal mechanical stress which had caused solder joints to fail. The potting did nothing to solve the repeated temperature cycling problem (probably made it worse). The potting certainly made it more difficult to do the investigation. The conclusion is that potting may be a good thing to avoid moisture, contamination, broken component leads for non surface mount components but it isnt going to prop up a basically poor mechanical/thermal design. The Ducati regulator is not quality engineering on a number of levels and deservedly has a poor reputation. It should noted that the Rotax generator is a permanent magnet generator with no field control and works on a different principle than the alternators being discussed in this thread.
KT

Agree.

From the reports I've seen on VAF about failures on various brands of regulators and alternators, most seem to be due to poor construction leading to mechanical breakages of hard wires and stuff falling apart from high thermal stress, often due to poor design or perhaps inadequate cooling.

This is where real engineering, validation and QC processes show big benefits in reliability- what Denso employs on a regular basis and small firms in the alternator manufacturing field (sorry for the pun) probably can't approach. Certainly one brand falls woefully short as we have seen time and time again from first hand reports here on VAF.
 
I love Japanese engines, in my cars, but put one in my aircraft... no thanks. I don't care how many millions of miles my Honda with an ND alternator goes, it's not the same thing, so that comparison is irrelevant. And I doubt you have 10,000 controllers flying either, so that is also a meaningless number as it pertains to aircraft reliability.
This is where we get into the emotional of debate. Walter I hear you and don't disagree, but an engine is not an alternator; that is a straw man argument. Also B&C sells a fine product but most of their alternators are based on the JAPAN ND alternator design and parts. From your comment you choose to have faith in a brand, especially if you spend 4 to 8 times. I don't think you are wrong. That does not make the other options bad.

I'm pretty sure the consensus on alternator reliability the clear winner is always B&C, show me some 'aircraft' reliability numbers to the contrary and I'll think about switching.
Consensus is only valid if it's based on fact and who you are asking in your poll. I have seen polls and no doubt B&C is reliable, not perfect they do fail. One poll showed that Plane Power was the worst with 28% failing within 250 hours. Apparently they went through some quality issues. "Emotionally" I would not buy a PP at this time. I Googled B&C and found several threads on Bonanza, Super Cub, GA Pilot forums of gripes about B&C. B&C can be installed on some certified airplanes by STC. Not bashing, just saying don't put too much faith into a product or company. Also quality can change over time for the worse. So many brands and products that were great in the past are now terrible.

Last the "show me" argument is a "red herring". You are asking for data that does not exist. B&C does not have hard reliability numbers. or test data. It does however have a good reputation over time, which get's back to the emotional argument. It's not likely you will be swayed by other RV'ers stating their generic ND auto alternator has 600 or 800 or 900 hours of trouble free reliable operation. The OV fear is hyped up due to one individual who does not like internal VR's. There is no data to back up the fear. OV is very rare unless pilot induced. Regardless of your alternator, inspect it every 12mo condition inspection, including brushes.

The most compelling reason to have a generic ND alternator besides the price being 1/4th that of the B&C, is if you ever have an issue on a trip you can exchange it at a local parts store. If you bought a "life time" auto part's store alternator even better. The down side is these alternators have a wide range of quality.... some are good, some are broken out the box. This is where learning how they work and what fails comes in. Learn how to take it apart and inspect and replace parts.

If you are married to an external VR you can modify the VR fairly easily to be externally regulated. There are so many choices. For some writting a check for $600 is the way to go. For some, they want to learn how to source an Alternator and make their alternator installation reliable. Others are laissez faire, get what is most available and least expensive, bolt it on go fly; replace it if it fails. Truly no clear winner, only what is best for you.
 
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ROTFL

I recently converted my perfectly functional ND alternator to external regulation after following every alternator thread I could find. I originally believed that the integrated ND regulator to be bulletproof and after gutting one to convert to the external regulation I'm even more convinced. As I ripped the guts out of this well potted, tiny board brimming with SMDs and replaced it all with some blobs of solder and lengths of copper wire I couldn't help thinking I just took a huge step backwards in reliability.

That said, I took that step backwards to protect against the one failure mode that the IR can't protect against - over voltage. I'm now electrically dependant and an overvoltage event will turn me into a glider in a split second. Yes, its unlikely that the IR will fail in the first place, but if it does go rouge, I can't expect that same misbehaving device to shut off power to the field. An externally regulated alternator has a physical hard wire to the field windings that if disconnected will absolutely shut down the alternator.

I looked at some brute force options like a transorb diode on the alternator output, but that would require a relay and a big CB. By the time you trip the chain of components and get the crowbar action, enough stray voltage my have made it to the ECU.

If anyone knows of a super fast acting device with enough capacity to cut off the snake's head before it strikes, I'm all ears. I'd go back to the IR Denso unit in a second.

After tearing into the PP I came to the exact same conclusion for external VR (by mod)!!!! Testing the pp on my crude bench, it is painfully obvious how sensitive the voltage on the field wire affects this design. Especially considering all the contact points, routing etc involved, and amazing it works as well as it does. Hopefully (and apparently) B&C got some special brush holder and connector socket made for supporting their reliability.

You, Ross, Keith, Walt and Sam, have some very good points that can withstand any intellectual/factual debate. Unfortunately, factual information for statistical failure rates and modes are non-existent for any of our alternators. B&C and PP are uncomfortably opaque with any knowledge that approaches these subjects, leaving our best source of information from the posters with the most eyes-on, hands-on experience.

There is a tag line seen on VAF that is fundamental," in theory, theory and practice are the same, but in practice they are not" . . . so true.
 
I originally believed that the integrated ND regulator to be bulletproof and after gutting one to convert to the external regulation I'm even more convinced. As I ripped the guts out of this well potted, tiny board brimming with SMDs and replaced it all with some blobs of solder and lengths of copper wire I couldn't help thinking I just took a huge step backwards in reliability.

That said, I took that step backwards to protect against the one failure mode that the IR can't protect against - over voltage

I looked at some brute force options like a transorb diode on the alternator output, but that would require a relay and a big CB. By the time you trip the chain of components and get the crowbar action, enough stray voltage my have made it to the ECU.

If anyone knows of a super fast acting device with enough capacity to cut off the snake's head before it strikes, I'm all ears. I'd go back to the IR Denso unit in a second.
Great post but I would put a finer point on with one thing. I-VR alternators DO have OV protection but it's different from a "crow bar". It has proven to be very reliable, not withstanding the quality of clone parts, Taiwan, Malaysia, China vs. original ND Japan produced.

Take a look at this IC chip. Page one shows a typical application. The field is driven by a MOSFET. Page 2 shows the inner workings of the IC, more sophisticated than a B&C voltage regulator. It does soft start, monitors shorts, under and over voltage, while controlling the alternators field (which controls Alt output). The IC has internal redundancy and fault monitoring.

https://www.mouser.com/datasheet/2/302/mc33099-1188084.pdf

The IC drives an external MOSFET power transistor. Pretty bullet proof transistor. The IC controls the flow through that transistor to the field. The IC is very well protected and has redundancy. Any under, over, short will dump the control power (GATE) to the field power transistor. What if the MOSFET fails? IC removes power to the transistor gate which shuts the power down to field and alternator shuts down..... MOSFET transistor is likely to fail OPEN, so problem is no power from the alternator. However they could fail shorted. If that happened it would get very hot and melt then open. This is a very rare occurrence. Still keeping it as cool as possible is goodness, even though they are rated to 120 C.

What does the B&C do. It is a simple VR and can fail due to diode, resistor, transistor failures. However on top of the VR is a "crow bar". It is typically a thyristor or SCR (silicon controlled rectifier) There are many trade names. It is a switch, will pull down, close a circuit with a small input voltage. This will DEAD SHORT the power to VR/field to ground. It shorts and pops a CB (or blows a fuse). It's brute force, shorting power to ground to blow circuit protection. It does work unless it does not. SCR can fail as well. Also unlikely.

OV is pretty rare. Loss of electrical power is more common than OV. Again a lot of this fear comes from the mechanical external voltage regulator days. Aircraft alternators in GA have always been AUTOMOTIVE based. Some of the old certified stuff is pretty scary by today's standards. Most alternators die and fail to produce power.... However to each his own. I have seen photos and description of doing I-VR to E-VR surgery as being a little crude, but it works.
 
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Good post George. I never knew Denso IR alternators had OV protection built in, only that I've never seen one OV in many years of owning them and wrenching on Toyota products for a living.
 
There is a lot of good info and discussion here------moved it to the "electrical system" forum, as it if valuable to more than just the RV7 folks.

And, easier to find in the future.
 
Great post but I would put a finer point on with one thing. I-VR alternators DO have OV protection but it's different from a "crow bar". It has proven to be very reliable, not withstanding the quality of clone parts, Taiwan, Malaysia, China vs. original ND Japan produced.

Take a look at this IC chip. Page one shows a typical application. The field is driven by a MOSFET. Page 2 shows the inner workings of the IC, more sophisticated than a B&C voltage regulator. It does soft start, monitors shorts, under and over voltage, while controlling the alternators field (which controls Alt output). The IC has internal redundancy and fault monitoring.

https://www.mouser.com/datasheet/2/302/mc33099-1188084.pdf

The IC drives an external MOSFET power transistor. Pretty bullet proof transistor. The IC controls the flow through that transistor to the field. The IC is very well protected and has redundancy. Any under, over, short will dump the control power (GATE) to the field power transistor. What if the MOSFET fails? IC removes power to the transistor gate which shuts the power down to field and alternator shuts down..... MOSFET transistor is likely to fail OPEN, so problem is no power from the alternator. However they could fail shorted. If that happened it would get very hot and melt then open. This is a very rare occurrence. Still keeping it as cool as possible is goodness, even though they are rated to 120 C.

What does the B&C do. It is a simple VR and can fail due to diode, resistor, transistor failures. However on top of the VR is a "crow bar". It is typically a thyristor or SCR (silicon controlled rectifier) There are many trade names. It is a switch, will pull down, close a circuit with a small input voltage. This will DEAD SHORT the power to VR/field to ground. It shorts and pops a CB (or blows a fuse). It's brute force, shorting power to ground to blow circuit protection. It does work unless it does not. SCR can fail as well. Also unlikely.

OV is pretty rare. Loss of electrical power is more common than OV. Again a lot of this fear comes from the mechanical external voltage regulator days. Aircraft alternators in GA have always been AUTOMOTIVE based. Some of the old certified stuff is pretty scary by today's standards. Most alternators die and fail to produce power.... However to each his own. I have seen photos and description of doing I-VR to E-VR surgery as being a little crude, but it works.

Any idea if ND puts this or an equivilant chips in ALL of it's IR remans or just more contemporary models? The need to manually kill the field is somewhat
moot, if the internal chip is monitoring and disconnecting on most failure modes. Knowing there could be other reasons to kill the alternator in an emergency, I suppose a relay on the B lead could be used instead of a pilot controlled field circuit. I just learned that I can get a factory reman'ed Denso from SUmmit for around $30.

Larry
 
I read the entire Alt Reliability thread and ran some numbers. I also contacted B&C for information. I was amazed how open they were with their own reliability information. It is the only company I contacted, so I can't say how open the other vendors are.

I had an auto engine conversion business so I did buy a lot of alternators a few years ago. The stuff I got from all of the major retail parts chains were mostly junk, out of the box. Over 50% were bad either out of the box, or within a few dozen hours. The local electric motor shop that rebuilt alternators for decades, stopped doing so. They said the only VR's they could source, were so bad they couldn't afford the warranty returns anymore. I ended up using used alternators from junk yards, or new ones from the dealer. Mostly used ones as the dealer wanted more than B&C prices. Used ones were usually 25-35 bucks.

I think auto alternators are fine, if you are careful where you source them from.

My choice is a single belt driven alternator, with 2 external VR's, switchable. The reliability poll, and brand B both mirrored my own opinion that most alternator failures (>75%) are VR failures. If I was using auto alternators with internal regulators, I would use 2 alternators.

My solution is a little lighter, but a little more expensive than 2 auto alternators. 2 good auto alternators might provide slightly more redundancy.

Anyway that was my choice.
 
Any idea if ND puts this or an equivilant chips in ALL of it's IR remans or just more contemporary models? The need to manually kill the field is somewhat
moot, if the internal chip is monitoring and disconnecting on most failure modes. Knowing there could be other reasons to kill the alternator in an emergency, I suppose a relay on the B lead could be used instead of a pilot controlled field circuit. I just learned that I can get a factory reman'ed Denso from SUmmit for around $30. Larry
Sure a B-lead relay connected to B+ could be done. See this link, middle sketch:

https://www.periheliondesign.com/lovm.htm

As far as IC's, if you find the specs on alternators, when you can find them, they read like the functions of these alternator VR IC's. What's inside a given VR, either genuine ND or clone/aftermarket voltage regulator? I will pass on going down that rabbit hole. We could dissect one and read the ID's on the components. Since they are potted it's hard to do. If you source an alternator or parts from a known good aftermarket manufacture you have some control. Malaysia, Taiwan, China are common locations. My preference was Taiwan from what I saw 10 yrs ago. I ended up sourcing a new ND alternator. Does ND (Japan) actually make them or do they outsource it out to the same folks making the clones? Who knows. VW's are made in Mexico and Honda's are made in Tennessee. A
 
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Does ND (Japan) actually make them or do they outsource it out to the same folks making the clones? Who knows. VW's are made in Mexico and Honda's are made in Tennessee. A

Denso can't afford substandard parts quality to save a few pennies by offshoring components. I'd guess that any plant they set up outside Japan would be supervised by Japanese and employ the same process control and QC as is used in Japan.

You don't risk a 50 year reputation as the top OEM auto supplier of electrical components in the world. We've seen how that turned out for one supplier here...

I have a friend who works at Denso in Japan, I'll ask and see what he can find out.
 
Second PP 60 amp alternator failure on RV-10

First one that came with the kit failed at 191 hrs. Voltage down to 12.8 from 14.2 VDC. Whining over intercom below 1200 rpm. The STATOR was not secured properly with epoxy coating, hot glue or sealant. No star washers were used under screws. This caused the the stator wires to break down deep, which are unrepairable. Replaced stator for $80. Keeping this alternator for a spare. Prop was balanced (PP liked to blame all of their broken stator wires on vibration or heat), no #1 exhaust heat shield and no cooling blast tube used since new. No problem with rectifier, regulator, oval 3-pin connector or brushes. No signs of overheating.

Second one has now failed at 45 hrs. Voltage down from 14.2 to 13.6 VDC. I will let you know what I find on that one. Time for a change and I won’t be spending $600-$800 anymore on $100-$150 alternators. 3 pin oval connector replaced as part of my troubleshooting. No change. Replaced 9 year old PC925L just in case. No change. Replaced 3 yr old, 3rd PC680 aux battery. No change.
 
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First one that came with kit failed at 191 hrs. Diodes. Second one has failed at 45 hrs. Time for a change.

I hope you are holding Hartzell's feet to the fire for help on that early hour failure. Like an overnight shipment, teardown report, and labor to install the new one. Levi ( I think is his name) came on here and helped us at one time understand their improvements.

Do you know what failed? Did you use the new connector, or the old one?
 
2nd PP voltage decreasing

See my edit above. I will keep you guys informed.

There is nothing special about these overpriced alternators with their “proprietary” overvoltage protection. How many overvoltage occurrences have you heard of in automobiles or aircraft. It’s just a way to charge $500 more to us “rich” airboat owners.

I am not calling Hartzell. It is poor business practices and customer service to sell an alternator, then not provide repair parts or repair services at a minimum. Instead, they just recommend buying a new one. I trust my local guy with 50 years of experience.
 
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My Duralast 14184 finally quit last month after 24 years and 1000 hours of faithful service.
 
Internal to External VR conversion

Back to the basics.

Thanks for all the advice and information, but this is my configuration (as are many):

I have an auto alternator (Duralast 14824, 55amp) that is internally regulated as purchased from Autozone. I'm am pairing this with a B&C external regulator.

Question 1: I need to convert the round 3 pin (B+ not included) internal regulator to a one wire field input from the external regulator. The only information I've found is the Lynn French document which is not comprehensive and a bit confusing. Is there another approach for converting the internally voltage regulated alternator to an externally voltage regulated alternator?

Question 2: Is there a one wire, externally regulated alternator part # that only has the field input, and is rated at 55amp +?

KISS,
J
 
I have an auto alternator (Duralast 14824, 55amp) that is internally regulated as purchased from Autozone. I'm am pairing this with a B&C external regulator.

Question 1: I need to convert the round 3 pin (B+ not included) internal regulator to a one wire field input from the external regulator. The only information I've found is the Lynn French document which is not comprehensive and a bit confusing. Is there another approach for converting the internally voltage regulated alternator to an externally voltage regulated alternator?

Just did this to a Denso last week, good article in Kitplanes last Nov. Also last March or thereabouts.

Basically what I did was to ground one side of the brushes and bring a lead for the other side out for the regulator. I ended up using techniques from each of the Kitplanes articles.
 
Kitplane article:

Rewiring a Nippondenso Alternator

https://www.kitplanes.com/rewiring-a-nippondenso-alternator/

https://www.kitplanes.com/alternator-mods-without-major-surgery/

After reading these articles, I'm not a fan of either option. Is there a 50+amp auto alternator that I can get at the local auto parts supply that is single wire (no internal voltage regulator)? I'd need a part number or a make/model/year. I have a Duralast 14824, but it has the round 3 pin internal voltage regulator.

JC
 
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There are lots of old threads on using auto alternators. I've read through lots of those and it's still not clear what a good direction is. I'd like a 50+ amp, external regulator alternator. Preferably counter clockwise rotation. Also, I'd prefer not to have to swap the pulley to a single groove pulley. Anyone gone down this path recently?

Another thing I'm unclear about is the mounting bracket and whether the alternators require different brackets. There seem to be some previous discussion on this. Where is the best place to find the brackets?

There is always the B and C route but I'd like to understand the auto options better before making my final decision.

Did you get any further along? After reading a lot of pages about this, I still don't have a clear idea if there's a bolt on option that won't require modification. I don't have a lathe and spending 10 hours of my time to rewire or modify a cheap alternator or get someone to fabricate a bracket, I'd just as well buy a B&C.

(I'm going to be mounting a IO 360 M1B)
 
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