RickWoodall

RickWoodall

Well Known Member
Hooking a dynon sky view to a slickmag and a lightspeed plasma 2.
Now what I believe I need to do is run pin 32 standard
Rpm pickup to the left tab of key switch where mag p lead is hooked up
Then...run pin 35 LOW VOLTAGE rpm input to the right side post of the key switch, because lightspeed is low voltage output. Both pick ups to be protected with 30ohm resistors on an inch or two of good wire to help with vibrations at the keyswitch point

Can someone with a similar setup let me know if this sounds right? Thanks
 
tach

Hi Rick, Im still working on the wires myself.
The skyview manual pin 32 and 33 are both 10 volt inputs. ( L + R )
In the plasma install manual , looking at the INPUT connector, the circuit pins 6 and 13 are 10 volt , so I was going to use them. I dont see a need to use the LOW VOLT inputs. Maybe Dynon will chime in for us. :)
 
dynon

in 6-26 of the skyview install manual, there is the wire break down for the 4 pins. The last line before they move on to the manifold pressure sensor, is a line atht you have have an RPM source that outputs frequency based rpm signals that are smaller than 10 volts, such as LIGHTSPEED ignition outputs, use the low voltage RPM inputs.

So, i just was unsure...as I will I guess use one regular, for the mag side and one low voltage for the ei side. Just seemed a little fuzzy, so figured someone here would be able to clarify. Dynon is on holidays for the week. Thanks.
 
On all Plasma systems the 15 pin "D-sub" input connector to the system is pre-wired with its power and signal inputs. A pulse tach output is also provided on this connector. Refer to the Input Connector Diagram.
http://www.lightspeedengineering.com/Images/PlasmaINPUT.pdf

it shows the output as 10 volt square wave.

Im not able to find any ref to low voltage output in the plasma manual.

Maybe send an email to Klaus at plasma to ask if it does indeed output 10 volts, as his manual states. If its under 10v then yes you will need the low volts inputs into the skyview.
 
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Last time.

Last time Jamie...I promise.:eek:

So, I am with you on using pin 6 and 13 from the lightspeed INPUT to the dynon wire for EI tach readings on the dynon. Makes sense to me finally and is as lightspeed wishes. Not sure why DYNON makes it more difficult than it needs to be in the instructions, or why that info would not be wired out of the lightspeed OUTPUT..not INPUT side..but clearly I am having a brain issue here. I will just wire it as suggested and move forward.

So, did you then just do the mag side off the acs key for the left side mag tach readings?

No more questions honest!
 
Hi Rick,

Beware the LightSpeed tach. I don't believe the Plasma 2 actually outputs the tach signal; it is just that they use the same wiring diagram as the Plasma 2 Plus and Plasma 3. Even on the Plasma 3, some earlier units only output 5v - not enough for the Dynon. For absolute confirmation, contact Klaus and have your exact model (e.g. "2" vs "2 Plus" vs "3") and serial number ready.

For those asking about the reason for having that wire on the "Input Connector," the answer is simple - he ran out of pins on the Output connector. The output connector also has analog outputs for tach, as well as manifold pressure and timing advance - but those are all in milivolts, too low for the Dynon to use.

Finally, on the earlier model Dynons at least, it was not possible to have two tach sources which put out a differing number of pulses per turn. On a 4 cylinder airplane, the Mag will put out 2 pulses per revolution while the LS will output 4 pulses per rev. They were intending to fix that in a later release, don't know the status.

I finally simply wired up the mag. The RPMs hardly drop at all when turning off the Mag (when I do the rpm indication drops to zero, but you can hear the pitch remain the same) so it really doesn't seem important to me. If I ever DO hear the pitch drop I will KNOW there is a problem with the LS; however, since I have the crank sensor I am confident it is never going to be a timing issue.

Final thoughts: A perfect RPM source would have a pickup based off the engine turning, such as an optical sensor mounted on the Magneto (my old mag had that, but it was part of an old EMS system I sold to upgrade to the Dynon so it is gone). There are several rpm pickups out there including one from UMA and another from MGL, but I can't determine what type of signal they output from the info immediately available.

Edit: I think I remember someone tapping the signal pulse between the brain box and the coil to get RPM, and that that signal was about 12v. That may be possible, but I'd be cautious about anything that might cause an interruption of the current that powers the coils.
 
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Thanks

Its been a very slow learning curve for me, but finally all done. The dynon gets the left tach pickup (mag) off the acs 510 keyswitch post, a flex wire (tefzel) to a resister to the dynon wire. I do have the lightspeed 2+.

The lightspeed (R) signal comes off the INPUT d sub right out of the lightspeed box (that d pin had to be taken all apart to do that) and that goes to the dynon (striped low volatage feed) R side tach reading wire for the dynon.

And thats that. VERY frustrating as dynon says one thing, Klaus says another and builders all go in diff directions and swear their way is better. This seems to be the correct way and ok with dynon and lightspeed so..fingers crossed.

Thanks
 
I discovered the E/I in my plane did not put out a signal that the GRT would see, and was faced with two options.

Return the GRT for a modification, or install a mechanical signal unit from Vans-----then the tach would forever be independent of whatever ignition was installed.

Besides the Vans option was cheaper.

Bet you can guess I went with option 2.
 
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