From: "Stephen Izett stephen.izett@gmail.com" <flyrotary@lancaironline.net>
Received-SPF: pass
 receiver=logan.com; client-ip=209.85.210.175; envelope-from=stephen.izett@gmail.com
Content-Type: text/plain;
	charset=utf-8
Content-Transfer-Encoding: quoted-printable
Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\))
Subject: Re: [FlyRotary] Re: EC3 hardware notes
Date: Tue, 23 Jun 2020 10:02:26 +0800
References: <list-405803@logan.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
In-Reply-To: <list-405803@logan.com>
Message-Id: <58DEE0D5-22A4-4D71-87F6-8DFE6DF6894C@gmail.com>

Thanks Finn. Did you previously give us a the circuit? Do you have a =
sketch of it?
 I=E2=80=99ll mod the EC3 and see if that is the problem.

Cheers

Steve Izett


> On 23 Jun 2020, at 9:59 am, Finn Lassen finn.lassen@verizon.net =
<flyrotary@lancaironline.net> wrote:
>=20
> Well, that is what he told me to add to the EC3. That's all I know.
>=20
> Finn
>=20
> On 6/22/2020 9:37 PM, Stephen Izett stephen.izett@gmail.com wrote:
>> Thanks Finn.
>> Is this clamping circuit what Tracy used.
>> I=E2=80=99m trying to remember what he added in the EC2 though its in =
heatsink so I can=E2=80=99t tell looking.
>>=20
>> Steve
>>=20
>>> On 23 Jun 2020, at 9:22 am, Finn Lassen finn.lassen@verizon.net =
<flyrotary@lancaironline.net> wrote:
>>>=20
>>> Just for the record.
>>> <ommkelgblomchfkc.jpg>
>>> The 1K resistor and the two 2.7V zener diodes are the CAS input =
clamping circuit.
>>>=20
>>> The rest is for redundant +5V to control panel (mixture voltage =
being the critical one).
>>> Vcc3 is J2 pin1 (+5V to control panel).
>>> I just used BAX16 diodes because I had them. Any 100mA (16V reverse =
voltage or more) diode will do.
>>> LM78L05 flat side down. Left pin is output. Center pin is ground and =
right pin is input.
>>>=20
>>> <jjfkkebmdbnhneko.jpg>
>>> If you want to secure components against vibration make sure you use =
Natural Cure Sealant (non -acidic)!
>>> I'm using Dowsil 737 RTV sealant.
>>> The auto parts store RTV is acidic and you don't want your circuit =
board damaged (etched) by that.
>>>=20
>>> Finn
>>>=20
>>> On 6/17/2020 6:57 PM, Finn Lassen finn.lassen@verizon.net wrote:
>>>> In addition to the CAS input clamping circuit, Tracy also =
recommends shorting pins 1 and 3 of D18. The voltage drop across the =
diode to the PCM module causes slightly lower mixture and program =
voltage than the software was programmed for.
>>>>=20
>>>> However, if you are powering A and B controllers separately (e.g. =
separate fuses or busses), I have a better idea.
>>>> 1) Remove the D18 diodes (just below C45 which they feed).
>>>> 2) Add a LM78L05 (or similar) voltage regulator. After each (A and =
B) of the power (L1 and L2) input coils (+ on the big C20 and C21 =
capacitors) feed the input of the LM78L05 with a diode. Output of it =
goes to J2 pin 2 (or + on C45).
>>>>=20
>>>> Same principle as powering the PCM from either of the 5V regulators =
on the EC3 board, but the 0.7V diode drop now happens before the =
regulator, not after the 5V.
>>>>=20
>>>> CAS input clamping circuit:
>>>> 1) A 1K resistor between J2-5 and J2-15 (CAS input and ground).
>>>> 2) Two 2.7V zener diodes in series, arrows or striped ends (anodes) =
connected together. The non-striped ends (cathodes) to J2-5 and J2-15 =
respectively (CAS input and ground). (Basically in parallel with the 1K =
resistor). If you got the polarity of the zener diodes correct you =
should see the signal from the CAS sensor clamped to no more than 0.7 + =
2.7 =3D +-3.4 volts on an oscilloscope.
>>>>=20
>>>> I now have two bad chips (does not respond to reading or =
programming attempts -- do "work" in the EC3). The chip pins used to =
program the chip go to the Mode switch on the PCM. J2 pins 22 and 24. =
One might consider protection diodes for those pins. Oddly the pins =
continue working for Mode switch input, just not for re-programming the =
chip.
>>>>=20
>>>> The EC3 board was designed for in-circuit chip re-programming (set =
mode switch to zero or disconnect J2). Vpp/MasterClear are on J2 pin 11 =
(for A) and pin 1 (for B). PGC on pin 22 and PGD on pin 24. However, =
Tracy found that the combined capacitance of the programming pins of two =
chips made in circuit programming unreliable. I wonder if it might work =
if one could control the speed with which it communicates with the chip?
>>>>=20
>>>> Finn
>>>>=20
>>>>=20
>>>> --=20
>>>> Homepage:  http://www.flyrotary.com/
>>>> Archive and UnSub:   =
http://mail.lancaironline.net:81/lists/flyrotary/List.html
>>>>=20
>>>=20
>>=20
>> --
>> Homepage:  http://www.flyrotary.com/
>> Archive and UnSub:   =
http://mail.lancaironline.net:81/lists/flyrotary/List.html
>>=20
>=20
>=20
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   =
http://mail.lancaironline.net:81/lists/flyrotary/List.html