Hi Jan Olieslagers & Silvaire,
Let me introduce myself: . *Mart*_Underline_ , Dutch and owner of 2 motorcycles which both had the Ducati Energia R & R and the Ducati 300W single phase Alternator (just as used in the ROTAX 912).
I happen to be the Chap who has been persuaded by Karlchen9 to test the Schicke GR6 German Rectifier /Regulator after already having tested the Electrex World RR51 and Silent Hektik R4412 as potential replacements for the Ducati Energia..
*Background*_Underline_
Both my Mçycles had already run substantial mileages (40,000 Km for a Ducati 900SS (1997) and 57,000 km for a Moto Guzzi Daytona (1992) with Electonic Fuel Management (Marelli P8 ECU: very advanced at that time), but potentially very sensitive to voltage spikes.
Both regulators are mounted in the airstream at the front of the Motorcycle (as the manufacturer intended)..
I blew the Ducati regulator on the Ducati M’ cycle some 100 hours after increasing the headlamp rating from 65 W to 130 W (ralley bulb) in summer 2012..
Thereafter (2012) I purchased a Silent Hektik R4112 which remained All Right but eventually I had to swap the front lamp back to 65 W because the lamp socket had molten (plastic), due to the increased heat of the 130W/130W H4 bulb.
So you could conclude that the SH is OK for the higher loading, but so was the Ducati Energia for its intended load (though only having a marginal Safety Factor)!
On the Dutch Moto Guzzi forum somebody posted the the schematic of the Ducati R & R and out of curiosity I did a Literature Search on this Regulator on the Internet and decided to upgrade the design by using 80 Amps Thyristors and 80 Amps recifiers ) and using HV (300V MPSA92) transistors (instead of the 25Amps LV design).
When doing some further literature search on the Internet (even going back to the orginal Ducati Energia Patent (1977!!) , I understood that this regulator was originally (1974) designed for small 250CC Motorcycles, with NO electronics to speak off (breaker point ignition, no electric starter, generator 100W).
For this application it is a robust (and at the time 1974!) advanced design.
However, having 25 Amps Thyristors and 25 Amps rectifying diodes (and using a lot of instrumentation which is sensitive to spikes) it is really taken way out of it’s intended design brief (especially in combination with a 300W (25 Amps) alternator (SF=0) ; No wonder that it fails, especially if you do not cool it properly, like in your planes!.
The Silent Hektik Regulator on the other hand uses stronger and more modern Thyristors (37 AMPS RMS, 47 Amps Peak) and a voltage protection circuit (also presumably using Thyristors) on the AC input; A much superior design with a lager Safety Factor .( it also dissipates less heat due to the modern thyristors/rectifying diodes)..
I had a spare SH (ready for the Guzzi but so far not at all needed) and have tested this sample
My conclusions are summarised as follows:
1) Series Regulator (14.0 V) with shunt protection circuit at 26V at the AC input.
2) Vsense point (C) starts device at 11.4 V and shuts it off at 13.9V.
3) Less parasitic heat compared to the Ducati R & R due to superior Thyristors/Rectifiers
4) Can be disconnected from the battery (not recommeded) with running engine (without selfdestruction), but reacts with a Voltage peak which might destroy your instrumentation.
5) Therefore a capacitor at B+ regulator 33000 uF, *63V*_Underline_ should be mounted as closely as possible to the regulator and a voltage spike protection (transil diode) on the BUS is highly recommended.
6) Very benign on the alternator (in contrast to the Electrex World or Shingenden Shunt regulators ) which shortcircuit the alternator and always load this to full power (25A → early failure of stator whilst preserving the regulator!).
7) The SH regulator is very well made (milled aluminum housing with much larger cooling fin area ) and solid Aluminum bottom (2 years + 3 months guarantee).
Very recommended in my view in contrast to the Electrex (or Shingend FAA012 or FAA020) who might burn your stator (Aprilia and Suzuki alternator failure sagas with Shunt regulators)!
For those interested I could upload my measuring report and scope pictures, but I just stumbled over some YouTUBE movies of a guy in the US of A (who has done exactly the same as I did (although he has a much more modern scope and variac).
So Irefer to his results and you tube movies.
http://ctflier.com/index.php?/topic/2371-regulator-rectifier-longish-and-techie/page-2
My adviceUnderline: The Silent Hektik R4412 is very much recommended for your planes but DO MOUNT IT IN THE AIR STREAM, not under the dash in the cockpit and also not in the engine bay behind hot exhausts (this is also the recommendation of the manufacturer.
Cheers and best regards,
*Mart*__Italic__
@redguuz, We have two motorcycles in common 
On those two bikes, I’ve no charging system issues to date. My most recent issues are with another Ducati that has the one-year 450W single-phase Ducati alternator. The Silent Hektik unit might do the job, without margin, but it won’t fit into the standard mounting area. Maybe next time it breaks, I’ll take on a bigger project including rewiring and relocation, but time is always an issue.
On an injected engine (e.g. the Daytona) dont forget to replace your fuel filter occasionally, to minimize pump electrical load.
I’m sure the Silent Hektik unit will work fine for the Rotax alternator, and I wouldn’t choose a Ducati Energia RR for an aircraft.
Thanks much
Redguuz, welcome from another electronic boffin
@redguuz: I think you overrate the importance of mounting the rectifier/regulator in the wind/air stream. Aircraft try to be streamlined, they keep the wind outside as much as they can, while keeping electrics inside. So it is not easy to achieve, nor should there be any need: the designers both at SH and Mr. Schicke limited dissipation, thereby also limiting the need for cooling. My own Schicke GR6 lives under the dashboard and seems quite happy there. I never noticed it to be more than handwarm. I did take care to mount it with the cooling fins vertical, though, so that convection can do its part.
@redguuz: also you should not overrate the importance of reliability of the electrics. The Rotax engine is almost exclusively used on non-certified aeroplanes, ultralights mostly, and they do not depend on electricity in any way. If all electrical power fails in my humble machine, I can still safely and confidently fly to the nearest aerodrome, and put the bird down in all serenity and perfectly legally (if I don’t choose a major airport). Ultralight training stresses this again and again.
@Silvaire and at @redguuz: excuse me for being pecky on vocabulary but in this case at least it is relevant: the Rotax 912 does NOT have an alternator. It has an arrangement that I understand to be more like a motorcycle’s (which both of you know better than I): a simple coil into which power is induced by rotating magnets, with no kind of field coil or such. Thus, there is no “primnary” regulation as is essential on an alternator.
By the way, did you know some 912’s have an option for adding an alternator as a redundant secondary source of electric power? It is apparently required for IFR installations. I have never seen one installed, though.
My own conclusion: for use on a Rotax 912, the Schicke GR6 is perfectly adequate. It can handle all the power that it can ever get on its plate, produces a fine stable voltage, and does not overheat. For use on a motorcycle, the extra capacity of the Silent Hektik may well be justified, that is outside my knowledge/experience. Those who wish to be on the super safe side can install a Silent Hektik on their 912, it can never hurt but it seems overkill to me – at double the price, more or less.
Whether an electrical machine has excited or PM field, its still an alternator if it makes alternating current.
As you may imagine, Rotax 912s modified for UAV use produce a great deal more electrical power than standard engines.
Dear Jan,
Sorry to disagree with your statements.
1) As Silvaire already indicated , a Permanent Magnet Alternator (e.g. a “Fietsdynamo”) is still an Alternator.
https://en.wikipedia.org/wiki/Alternator
2) Both mr Kurpass and mr. Schicke (resp designers of the SH R4112 and the Schiche GR6) underline the requirement of forced cooling of their regulatorsItalic to enhance the allowable heat dissipation of their regulators.
It is a physical law that forced cooling (“forced convection”) will enhance Heat Transfer by an order of magnitude compared to natural convection.
The fact that you might “get away with it” (no forced cooling) is apparently because your plane consumes relatively energy.
E.g the Silent Hektik with NO forced cooling (forced convection) gets only lukewarm (30 deg.C) for a load of 60 W; However for higher power offtakes (e.g 120 W for the SH) the regulator already becomes bloody warm (60 deg C). Even more power requirements would eventually destroy the regulator if you do not sufficiently cool it.
The same reasoning is applicable for the Schicke.
See also this website which shows the testing of the Ducati Energia R & R by a renowned institue.
http://contrails.free.fr/elec_ducati_en.php
Hence, if you can, it is better to cool your regulator by a forced airstream (is valid for a lot of engines as well).
BTW. I have received a Schicke Electronic GR6 via KARLCHEN9 vand will assess to what power offtakes this regulator (with a relatively large cooling Fin area, hence lower thermal resistance) will remain acceptable cool.
“meten is weten” .
Regards,
Mart
Whether an electrical machine has excited or PM field, its still an alternator if it makes alternating current.
< muttering under breath >
I do not like to be beaten on vocabulary issues but I cannot entirely exclude the possibility that there might be a certain degree of fact here.
< / mutter >
Seems like I was using the term “alternator” in its usual automotive meaning. Still, the big cylinder in my push-bike’s frontwheel axle is called a hub dynamo, not a hub alternator… oh well.
@Redguuz: looking forward to your measurements!
Jan, permanent magnet alternators like that on the Rotax were intoroduced on motorcycles in the early 1950s… Lucas called them RM Alternators, for Rotating Magnet. Back then the regulation was really crude, the overall quality was horrendous, and the 1960s introduction of a zener diode to dump excess power into a heat sink was considered advanced technology OTOH it would sure be nice if the quality of modern electronics could be combined with the clarity of their technical literature , see page 20.
Silvaire,
Fully agree. (Thanks for this Lucas booklet, never saw it in this form!).
BTW My 2nd motorcycle as an old Norton Dominator 99SS having a 6V Lucas AC system (PMA alternator (60W) (1960) .).
I upgraded at that time (1977) to a more novel (at the time) version (12V, 150 W epoxy encasted), PMA alternator.
The selenium recifier was exchanged by a 1000V 30 A Silicon Graetz bridge (in the 1960’s only vulnerable selenium rectfiers existed!) and the Zener diode from Lucas (used in "modern"Triumphs at the time,) was added.
This 1970’s alternator plus regulation never gave any problems any more (I still own this bike as well!).
By adding a Lucas 2MC (4700uF capacitor) one could kickstart and run the Bike without battery.
(These conversions are now common).
The Norton ignition BTW was, initially also very obsolete and unreliable (originally Magneto LUCAS K2F, a rotating armature!!! magneto ) was exchanged by a Contactless Racing Ignition used in Cars (LUCAS RITA) and worked without any problems until now.
Years ago, I saw a vintage UltraLight plane with a Lucas Magneto system at the Aviodome museum, and thought. “Hell, I would never go in the air with such LUCAS electrics”.
So although LUCAS is known as the “Prince of Darkness” it was rather the Penny Pinching of the Buyers (NORTON, Triumph, BSA and let’s not forget Brithish Leyland) which forced them to make “suboptimal” products . No wonder that the entire British Motorcycle and Car Industry went “Tits Up”…
The underlying engineering however was sound and quite advanced at the time!
(Remember also that when this Zener diode was introduced, Hi power Thyristors were largely non available and very costly).
Going back to regulators : The Zener diode in the Lucas PMA installation can also be changed to a modern regulator (also for the Norton, BSA, Triumph): there are many products on the market:
see.e.g.
http://roosterignitions.com/products.php?cat=7
https://www.classicbritishspares.com/collections/norton-electrical?page=2
NB The British “Ohms Law” is identical to the Italian one (or German one for that matter), so one can mount a Brithis regulator on an Italian alternator etc.
Morale of the story: I would not skimp on the Electronics in a plane and Buy the Best (After All: “The Quality remains after the Price has been forgotten”).
Best regards,
Martin
I find this really weird. I used to build electronic ignitions in the early 1970s for motorbikes. I had a Yamaha YCS3E back then Thyristors, and a enormous range of bipolar power transistors, were fully available back then.
I can see that if you have a permanent magnet alternator then you are denied the opportunity to control the output by varying the field current, so your options are
The 2nd method is crude since it appears to use the battery as a giant capacitor, which guarantees blowing up all the electrics if the battery every got disconnected with the engine at a decent rpm.
But really this isn’t rocket science. My guess is that, in this particular field, the one-eyed man is king. A lot like GA aircraft electrics actually
If I was doing this, I would rectify with schottky diodes and use a PWM regulator afterwards (method #1). The power dissipation would be the output current times about 1V (for a 3 phase rectifier made up of 6 schottky diodes).
