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 5868450 for flyrotary@lancaironline.net; Thu, 08 Nov 2012 08:39:27 -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=OOOlLFmB 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=Ia-xEzejAAAA:8 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=7g1VtSJxAAAA:8 a=oCcaPWc0AAAA:8 a=Hi4bMH4R0JhAoU7YuRoA:9 a=wPNLvfGTeEIA:10 a=Qa1je4BO31QA:10 a=EzXvWhQp4_cA:10 a=UVa1AOFWpEO8p--o:21 a=IC74_ps-U7yzAhFo:21 a=E93lBu2AAAAA:8 a=nbLmX63qA9JKjreZHsIA:9 a=_W_S_7VecoQA:10 a=tXsnliwV7b4A:10 a=hO30gm18fF0A:10 a=MpuOTR30KwMA:10 a=8y3r-Fxw0wcA:10 a=ZUHL7eEe4EUA:10 a=8lfLvbM9VgMA:10 a=NWVoK91CQyQA:10 a=-4iFy3ot6KEK15py:21 a=7oG8U6KSqfC_4UIE:21 a=jtpRDWhmTHVNHUyS:21 a=g3L/TDsr+eNLfIieSKfGkw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.170.10 Received: from [174.110.170.10] ([174.110.170.10:49919] helo=EdPC) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id EF/3A-21565-EE5BB905; Thu, 08 Nov 2012 13:38:55 +0000 Message-ID: <3997DAEEE74D44CD820C0D63E16DA878@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Renesis CAS & EC-2 upgrade? Date: Thu, 8 Nov 2012 08:38:40 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004A_01CDBD8C.7455E5F0" 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_004A_01CDBD8C.7455E5F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Likewise, Steve. Seeing as how both the ignition and injector pulse drop out in that band = - it would seem to me that the problem must lie in the circuit common to = both which is the CAS signal processing circuit. If only one pulse = train, either the ignition or the injector pulses only dropped out, then = of course you would suspect the respective circuit - but, this is common = to both. =20 On the other hand, rotor 1 continues to run - but, as you noted - the = pulse duration for even rotor 1 in this rpm range does not appear = normal in that range. I suspect that since your 1K ohm resistor (which brings the peak voltage = down to 6 volts) where it appears to run ok at that point, that for = some reason the input circuitry has a problem handling the +13 volt peak = in the 660-1400 rpm range. Since this would fall in normal TTY signal = range (used by the microprocessor), I suspect that perhaps due to some = bandpass filter effect of the components in the input circuit that the = +13 volt peaks are overdriving the input circuit within that rpm range. = Adding the resistor changes the bandpass frequency and puts it = someplace (probably lower) out side your operating rpm range. But, again without knowledge of the input circuit and seeing what is = really going on inside the EC its difficult to say. Ed From: Steven W. Boese=20 Sent: Wednesday, November 07, 2012 11:35 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Renesis CAS & EC-2 upgrade? Ed, I always learn things from your discussions. An intriguing aspect of the rotor 2 dropout is that it occurs over a = band of RPM. Below and above this band, the engine apparently operates = normally. I've attached an image of the signals when the engine transitions to = missing rotor 2 as the RPM increases during startup. The plot is without = the signal from CAS 2 since the CAS 2 signal makes it harder to see what = is happening. Again, the voltages need to be multiplied by 3. As seen in the plot, rotor 2 signals for fuel injectors and ignition = coils disappear as RPM increases. Rotor 1 is also affected since the = dwell time for its coil signals is 1 ms in one case and 13 ms in the = next cycle. Before and after this time the dwell for all coil signals is = generally around 5 ms. My intention is to take Bobby's suggestion of removing the 1K resistor = on CAS 1 one step farther and install variable resistors in both = locations. This might enable the placing of limits on the effective = resistor values. If the resistor value is not critical to reliable = operation, I'll install fixed value resistors that are not close to the = limits and go with that. Tracy is really the only one who can address = the cause and effect and I'll just accept the fact that life will = continue to have its mysteries. Steve -------------------------------------------------------------------------= ------- From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf = of Ed Anderson [eanderson@carolina.rr.com] Sent: Wednesday, November 07, 2012 7:45 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Renesis CAS & EC-2 upgrade? 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 -------------------------------------------------------------------------= ------- -- 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_004A_01CDBD8C.7455E5F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Likewise, Steve.
 
Seeing as how both the ignition and injector = pulse drop=20 out in that band - it would seem to me that the problem must lie in the = circuit=20 common to both which is the CAS signal processing circuit.  If only = one=20 pulse train, either the ignition or the injector pulses only = dropped out,=20 then of course you would suspect the respective circuit - but, this is = common to=20 both. 
 
On the other hand, rotor 1 continues to run - = but, as you=20 noted - the pulse duration for even rotor  1 in this rpm range = does=20 not appear normal in that range.
 
I suspect that since your 1K ohm resistor (which = brings=20 the peak voltage down to  6 volts) where  it appears to = run ok at=20 that point, that for some reason the input circuitry has a problem = handling the=20 +13 volt peak in the 660-1400 rpm range.  Since this would fall in = normal=20 TTY signal range (used by the microprocessor), I suspect that perhaps = due to=20 some bandpass filter effect of the components in the input circuit that = the +13=20 volt peaks are overdriving the input circuit within that rpm = range.  =20 Adding the resistor changes the bandpass frequency  and puts it = someplace=20 (probably lower) out side your operating rpm range.
 
 But, again without knowledge of the input = circuit=20 and seeing what is really going on inside the EC its difficult to=20 say.
 
Ed
 

From: Steven W. Boese
Sent: Wednesday, November 07, 2012 11:35 AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: Renesis CAS & EC-2=20 upgrade?

Ed,

 

I always learn things from your = discussions.

 

An intriguing aspect of the rotor 2 dropout is = that it=20 occurs over a band of RPM. Below and above this band, the engine = apparently=20 operates normally.

 

I've attached an image of the signals when the engine=20 transitions to missing rotor 2 as the RPM increases during = startup. The=20 plot is without the signal from CAS 2 since the CAS 2 = signal=20 makes it harder to see what is happening. Again, the voltages need to be = multiplied by 3.

 

As seen in the plot, rotor 2 signals for fuel = injectors and=20 ignition coils disappear as RPM increases. Rotor 1 is also affected = since the=20 dwell time for its coil signals is 1 ms in one case and 13 ms in = the next=20 cycle. Before and after this time the dwell for all coil signals is = generally=20 around 5 ms.

 

My intention is to take Bobby's suggestion of removing = the=20 1K resistor on CAS 1 one step farther and install variable = resistors in both locations. This might enable the placing of limits on = the=20 effective resistor values. If the resistor value is not critical to = reliable=20 operation, I'll install fixed value resistors that are not close to the = limits=20 and go with that. Tracy is really the only one who can address the cause = and=20 effect and I'll just accept the fact that life will continue to have its = mysteries.

 

Steve

 

From: Rotary motors in aircraft = [flyrotary@lancaironline.net]=20 on behalf of Ed Anderson [eanderson@carolina.rr.com]
Sent: = Wednesday,=20 November 07, 2012 7:45 AM
To: Rotary motors in=20 aircraft
Subject: [FlyRotary] Re: Renesis CAS & EC-2=20 upgrade?

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

 

--
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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