X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 6.0c2) with ESMTP id 5866564 for flyrotary@lancaironline.net; Wed, 07 Nov 2012 09:46:31 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=2.0 cv=GZOVbHrL c=1 sm=0 a=g3L/TDsr+eNLfIieSKfGkw==:17 a=AHkS0RJitIMA:10 a=DGl3cIMJq9QA:10 a=05ChyHeVI94A:10 a=ayC55rCoAAAA:8 a=4YGqAiqMcKMA:10 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=7g1VtSJxAAAA:8 a=Ia-xEzejAAAA:8 a=oCcaPWc0AAAA:8 a=2ki_nqXiMotebCsZEtIA:9 a=wPNLvfGTeEIA:10 a=Qa1je4BO31QA:10 a=E93lBu2AAAAA:8 a=3IWEBB6hzdD_-k6uKBYA:9 a=_W_S_7VecoQA:10 a=EzXvWhQp4_cA:10 a=hO30gm18fF0A:10 a=MpuOTR30KwMA:10 a=ITy1QvswKHoA:10 a=mvWFUSSifWkA:10 a=C1REVoR1p7wA:10 a=NWVoK91CQyQA:10 a=gEh-sy-7biPHYRtb:21 a=g3L/TDsr+eNLfIieSKfGkw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.170.10 Received: from [174.110.170.10] ([174.110.170.10:50672] helo=EdPC) by cdptpa-oedge04.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id CD/7D-20885-4247A905; Wed, 07 Nov 2012 14:45:56 +0000 Message-ID: <008D8062D02E4253AE56419BB1672768@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Renesis CAS & EC-2 upgrade? Date: Wed, 7 Nov 2012 09:45:51 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0027_01CDBCCC.AC2AF8A0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_0027_01CDBCCC.AC2AF8A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Steve, Always impress with your digging into these anomalies! So what are the relevant factors looking at the black box. =20 One thing we know is that the interval between pulses becomes greater = as the rpm is lowered. While the peak voltage probably remains fairly = constant - the average voltage will decrease due to the lower pulse duty = cycle. Also based on your analysis, a 1K ohm load on the input circuit = reduces the pulse peak voltage level from approx +13.5 volts to around = +6.00 volts peak - which given the same pulse duty cycle would mean even = a lower average voltage - after which the engine runs OK at lower rpm. = =20 I suspect the EC has a limiting circuit of some type to reduce the +13.5 = volt peaks to that suitable for input to a microcontroller chip = (generally +5 volts TTY). I use a combination of a zener diode and a = dropping resistor in my EFISM such that any voltage above 5 volts causes = the diode to conduct and clip/limit the peak to around 5 volts. There = are, of course, many other voltage limiting circuit methods with = different characteristics that might be affected differently with a = lower peak or average voltage or the 1K loading.=20 Analog SWAG: Interaction of pulse train and a capacitive element of the EC IF for example the circuit was such that the pulse train kept some = capacitive element repeatedly trigger so as to be discharged between = pulses with the rpm above a specific rpm, then as the duration between = pulses became longer (with the lower rpm) it might reach a critical = point where the capacitor never becomes completely discharged -I.e the = discharging pulse does not occur frequently enough to bring/keep the = capacitor to zero volt level between pulses - as an example. Adding the = resistor may result in a quicker discharge circuit than without the = resistor- thereby again permitting capacitor to completely discharge = between pulses and the circuit to work at lower rpms . This quicker = discharge and the lower peak voltage may combine to permit the = capacitor to completely discharge at your lower rpm. The lower voltage = seen may only be a side effect and not the reason for the circuit now = working. Just one thought. Digital SWAG: I don't see how the 1K resistor would play in this scenario, but I'm = throwing it in for consideration. One problem I ran into early on with my EFISM was that the Pulse circuit = in the microchip had only a word (16 bits) wide register to store pulse = timing data, meaning that no more that 65535 CPU clock tics could be = stored. In my case with an 8Mhz clock tic it mean that any Low rpm with = an interval of greater than 122 msec (approx 500 rpm or lower) would = overflow the word memory size - causing errors. If the CPU clock tic is = at a higher rate the minimum rpm is raised and if lower cock tic rate = the min rpm level is lower.=20 I had to add a flag to signal when the pulse duration memory register = overflowed and then use that flag (when set) to add 65535 to the pulse = interval clock tic count to calculate the correct rpm, otherwise the rpm = calculated was in error. So again, this is probably not a factor - as I don't see where the 1K = resistor or lower peak voltage would play a role, but thought I would = throw it out for consideration. All I can think of for the moment Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com From: Steven W. Boese=20 Sent: Tuesday, November 06, 2012 7:50 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Renesis CAS & EC-2 upgrade? A follow-up on the attempt to use Renesis CAS with an EC2 controller set = up for '86 stock Mazda CAS. =20 There appeared to be a correlation between loosing the rotor 2 = controller signals with crossing the staging threshold on startup. This = was tested by starting the engine with the throttle open sufficiently = that the manifold pressure should not drop to less than the staging = threshold. The result was that the engine still ran only on rotor 1 = until RPM reached at least 1400 RPM. It just didn't take as long to = reach this RPM as before. This behavior and examination of controller = signals recorded during the startup disproved the appearance of a = correlation between loosing rotor 2 controller signals and staging. 1K ohm resistors were then added between each Renesis CAS signal and = ground. With these resistors installed, the engine started easily and = ran normally at all throttle settings. Since the engine was operated = with this setup for only a few minutes, it is unknown if this is a = reliable solution. If it isn't, it is certainly a step in the right = direction. Plots of the CAS signals with and without the 1K ohm = resistors are attached. The voltage scales on the two plots are the = same, but voltages read from the plots must be multiplied by a factor of = 3 to give absolute values in volts. Higher resolution plots of the CAS = signals are available on request. Any feedback on why adding the = resistors is effective would be welcome. Steve Boese RV6A, 1986 13B NA, RD1A, EC2 =20 -------------------------------------------------------------------------= ------- From: Steven W. Boese Sent: Monday, November 05, 2012 1:50 PM To: Rotary motors in aircraft Subject: Renesis CAS & EC-2 upgrade? I have the 2011 Renesis engine running on my test stand...sort of. On = startup, when the manifold pressure drops below the staging threshold, = both ignition signals and the primary injector signal from the EC2 are = missing on rotor 2 on the next cycle after the dropping of the secondary = injector signals on rotors 1 and 2. This occurs at about 870 RPM. The = engine then runs on just rotor 1 until the RPM reaches the range from = 1420 to 1750 at which time the rotor 2 coil signals and primary injector = signal return. The engine runs normally up to 5350 RPM which is as = fast as the prop load will allow. If the engine is idled into the rpm = range less than around 1700, it goes back to running only on rotor 1 = with the rotor 2 primary injector and coil signals missing. =20 The CAS for this engine is set up as 2 Renesis CAS units, one triggered = from a eccentric shaft mounted 12 tooth wheel and the second CAS = triggered from a single pin on the side of the 12 tooth wheel. The 12 = teeth are the same size and shape as those on the stock Renesis wheel. = It was hoped that this would allow use of the same EC2 controllers that = were used on the '86 engine with the stock CAS with the 24 and 2 tooth = pickups. Searching the archives indicates that trying a 1K ohm resistor from each = Renesis CAS to ground and/or limiting the CAS voltage with the circuit = suggested by Bobby Hughes might be worth trying. Traces of the Renesis = CAS and the stock '86 CAS are attached. The recording uses a factor of = 3 divider so the voltage scale for each trace must be multiplied by 3 to = give actual volts. The white trace is of the 1 tooth Renesis or the 2 = tooth "86 CAS while the colored trace is of the 12 tooth Renesis or 24 = tooth "86 CAS. The amber vertical and horizontal lines are software = generated cursors, not EC2 signals. One thing of note may be that the = Renesis 1 tooth signal crosses zero between triggers whereas the 2 tooth = '86 signal remains above zero between triggers. There is no discernable = change in the Renesis CAS signals when the transition to missing the = Rotor 2 signals takes place. There is also no discernable noise on the = CAS signals under the measurement conditions of 3000 samples per second. Any suggestions for investigating this issue would be appreciated. Steve Boese RV6A, 1986 13B NA, RD1A, EC2 -------------------------------------------------------------------------= ------- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html -------------------------------------------------------------------------= ------- No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.2742 / Virus Database: 2617/5875 - Release Date: = 11/05/12 ------=_NextPart_000_0027_01CDBCCC.AC2AF8A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Steve,
 
Always impress with your digging into these = anomalies!
 
So what are the relevant factors looking at the = black=20 box. 
 
One  thing we know is that the interval = between=20 pulses becomes greater as the rpm is lowered.  While the peak = voltage=20 probably remains fairly constant - the average voltage will decrease due = to the=20 lower pulse duty cycle.  Also based on your analysis, a 1K ohm load = on the=20 input circuit reduces the pulse peak voltage level from approx +13.5 = volts to=20 around +6.00 volts peak - which given the same pulse duty cycle = would mean=20 even a lower average voltage  -  after which the engine runs = OK at=20 lower rpm. 
 
I suspect the EC has a limiting circuit of some = type to=20 reduce the +13.5 volt peaks to that suitable for input to a = microcontroller chip=20 (generally +5 volts TTY).  I use a combination of a zener diode and = a=20 dropping resistor in my EFISM such that any voltage above 5 volts causes = the=20 diode to conduct and clip/limit the peak to around 5 volts.  There = are, of=20 course, many other voltage limiting circuit methods with different=20 characteristics that might be affected differently with a lower peak or = average=20 voltage or the 1K loading. 
 
Analog SWAG:
 
Interaction of pulse train and a capacitive = element=20 of  the EC
 
IF for example the circuit was such that the = pulse train=20 kept some capacitive element repeatedly trigger so as to be = discharged=20 between pulses with the rpm above a specific rpm, then as the = duration=20 between pulses became longer (with the lower rpm) it might reach a = critical=20 point where the capacitor never becomes completely discharged -I.e=20  the discharging pulse does not occur frequently enough to = bring/keep the=20 capacitor to zero volt level between pulses - as an example.  = Adding=20 the resistor may result in  a quicker discharge = circuit than=20 without the resistor- thereby again permitting capacitor to completely = discharge=20 between pulses and the circuit to work at lower rpms .  This = quicker=20 discharge and the lower peak  voltage may combine to permit = the=20 capacitor to completely discharge at your lower rpm.  The =  lower=20 voltage seen may only be a side effect and not the reason for the = circuit=20 now working.  Just one thought.
 
Digital SWAG:
 
I don't see how the 1K resistor would play in = this=20  scenario, but I'm throwing it in for consideration.
 
One problem I ran into early on with = my EFISM=20 was that the Pulse circuit in the microchip had only a word (16=20 bits) wide register to store pulse timing data, meaning that no = more that=20 65535 CPU clock tics could be stored.  In my case with an 8Mhz = clock tic it=20 mean that any Low rpm with an interval of greater than 122 msec (approx = 500 rpm=20 or lower) would overflow the word memory size - causing errors.  If = the CPU=20 clock tic is at a higher rate the minimum rpm is raised and if lower = cock tic=20 rate the min rpm level is lower. 
 
 I had to add a flag to signal when the = pulse=20 duration memory register overflowed and then use that flag (when set) =  to=20 add 65535 to the pulse interval clock tic count to calculate = the correct=20 rpm, otherwise the rpm calculated was in error.
 
So again, this is probably not a factor - as I = don't see=20 where the 1K resistor or lower peak voltage would play a role, but = thought I=20 would throw it out for consideration.
 
All I can think of for the = moment
 
Ed
Edward L. Anderson
Anderson Electronic = Enterprises=20 LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com

From: Steven W. Boese
Sent: Tuesday, November 06, 2012 7:50 PM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: Renesis CAS & EC-2=20 upgrade?

A follow-up on the attempt to=20 use Renesis CAS with = an EC2 controller set up for '86 stock Mazda=20 CAS. 

 

There appeared to be a correlation between loosing the rotor 2 = controller=20 signals with crossing the staging threshold on startup.  This was = tested by=20 starting the engine with the throttle open sufficiently that the = manifold=20 pressure should not drop to less than the staging threshold.  The = result=20 was that the engine still ran only on rotor 1 until RPM reached at least = 1400=20 RPM.  It just didn't take as long to reach this RPM as = before. =20 This behavior and examination of controller signals recorded during the = startup=20 disproved the appearance of a correlation between loosing rotor=20 2 controller signals and staging.

 

1K ohm resistors were then added between=20 each Renesis CAS signal and = ground. =20 With these resistors installed, the engine started easily and ran = normally at=20 all throttle settings.  Since the engine was operated with this = setup for=20 only a few minutes, it is unknown if this is a reliable solution.  = If it=20 isn't, it is certainly a step in the right direction.  Plots of=20 the CAS signals with and without = the 1K=20 ohm resistors are attached.  The voltage scales on the two plots = are the=20 same, but voltages read from the plots must be multiplied by a = factor=20 of 3 to give absolute values in volts. =20 Higher resolution plots of the CAS = signals=20 are available on request.  Any feedback on why adding the resistors = is=20 effective would be welcome.

 

Steve Boese
RV6A, 1986 13B NA,=20 RD1A, EC2

 

  

From: Steven W. Boese
Sent: Monday, = November 05,=20 2012 1:50 PM
To: Rotary motors in aircraft
Subject: = Renesis=20 CAS & EC-2 upgrade?

I have the=20 2011 Renesis engine running on my test stand...sort = of.  On=20 startup, when the manifold pressure drops below the staging = threshold, both=20 ignition signals and the primary injector signal from = the EC2=20 are missing on rotor 2 on the next cycle after the dropping of the = secondary=20 injector signals on rotors 1 and 2.  This occurs at about 870=20 RPM.  The engine then runs on just rotor 1 until the RPM = reaches the=20 range from 1420 to 1750 at which time the rotor 2 coil signals and = primary=20 injector signal return.   The engine runs normally up to = 5350 RPM=20 which is as fast as the prop load will allow.  If the engine is = idled into=20 the rpm range less than around 1700, it goes back to running only on = rotor 1=20 with the rotor 2 primary injector and coil signals missing. =20

 

The CAS=20 for this engine is set up as 2 Renesis CAS = units, one=20 triggered from a eccentric shaft mounted 12 tooth wheel and the=20 second CAS triggered from a single pin on the side of the 12 = tooth=20 wheel. The 12 teeth are the same size and shape as those on the=20 stock Renesis wheel.  It was hoped that this would = allow use of=20 the same EC2 controllers that were used on the '86 engine with the=20 stock CAS with the 24 and 2 tooth pickups.

 

Searching = the archives=20 indicates that trying a 1K ohm resistor from=20 each Renesis CAS to ground and/or limiting=20 the CAS voltage with the circuit suggested by Bobby Hughes = might be=20 worth trying.  Traces of the Renesis CAS = and the=20 stock '86 CAS are attached.  The recording uses a = factor of 3=20 divider so the voltage scale for each trace must be multiplied by 3 to = give=20 actual volts.  The white trace is of the 1 = tooth Renesis or the=20 2 tooth "86 CAS while the colored trace is of the 12=20 tooth Renesis or 24 tooth "86 CAS.  The amber = vertical=20 and horizontal lines are software generated cursors, not EC2 = signals.  One thing of note may be that the Renesis 1 = tooth=20 signal crosses zero between triggers whereas the 2 tooth '86 signal = remains=20 above zero between triggers.  There is no discernable change in=20 the Renesis CAS signals when the transition to = missing=20 the Rotor 2 signals takes place.  There is also no discernable = noise on=20 the CAS signals under the measurement conditions of 3000 = samples per=20 second.

 

Any = suggestions for=20 investigating this issue would be appreciated.

 

Steve=20 Boese

RV6A,=20 1986 13B NA, RD1A,=20 EC2

--
Homepage:  http://www.flyrotary.com/
Archive and=20 UnSub:  =20 http://mail.lancaironline.net:81/lists/flyrotary/List.html

No virus found in this=20 message.
Checked by AVG - www.avg.com
Version: 2013.0.2742 / = Virus=20 Database: 2617/5875 - Release Date: 11/05/12

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