DA 120 with onboard Tach.

[stangflyer]

Really cool....and "USEFUL" thread Kelly. May have to put it to use.

 

[49dimes]

Really cool....and "USEFUL" thread Kelly. May have to put it to use.

Hey Rob,

In all honesty you could run an Rcexl ignition that has the tach connection built in. 3Dub did it years ago when they introduced MC (micro processor controll) ignitions to their line. One thing on these DA ignitions, other than they can wear your arm out, is that their advance curve starts right at 2000 rpm. Using the tach I saw a reliable idle down to 13/1400 rpm but shakin and bakin. Once 2k reached smooth as silk. That is with the pick up moved as far to the right when looking head on at the engine.

 

[49dimes]

@Alky6

In a nut shell the "Hall Effect" of a semiconductor needs voltage to "clamp" "shunt" harmonic transients "noise"that get generated by varying rpms sensed through the rotating magnet on the prop hub. The semiconductors used in our RC applications is merely an on or off device activated by the magnet. The resistor provides this clamping voltage or shunt to greatly reduce or cancel harmonic transients. This type of information is widely available through the internet and you can study manufactories such as Seiko, Texas Instruments etc.. and even read techno -geek blogs or teaching videos massed out to the general public. Search Engines are cool!

 

[stangflyer]

@Alky6

In a nut shell the "Hall Effect" of a semiconductor needs voltage to "clamp" "shunt" harmonic transients "noise"that get generated by varying rpms sensed through the rotating magnet on the prop hub. The semiconductors used in our RC applications is merely an on or off device activated by the magnet. The resistor provides this clamping voltage or shunt to greatly reduce or cancel harmonic transients. This type of information is widely available through the internet and you can study manufactories such as Seiko, Texas Instruments etc.. and even read techno -geek blogs or teaching videos massed out to the general public. Search Engines are cool!

What's all this talk about Hall effects, and clamps and shunts and harmonic transients and semiconductors? You sir, are much more intelligent than you have led us all to believe. And here we thought you were just another guy with some "TOY" airplanes. LOL

 

[49dimes]

I said I was going to keep it plane clothes but Alky6 opened the door! Thanks for the nice complement Rob.
And all said.... I do like them toy airplanes! And Search Engines.....And Engines....And Trains.....And things that go around and around.LOL

 

[3D-Joy]

.....And things that go around and around.LOL

So I'm sure you like the Kadet Senior

 

[Alky6]

I said I was going to keep it plane clothes but Alky6 opened the door!

What do you expect...I am an engineer, I love getting in the weeds! Though sometimes it is a bit much. Thanks for the reply. I will bite my tongue on the differences of two wire and three wire hall effects... Google is my friend. LOL

 

[IMAC FANATIC]

OK, need some help.
Have spektrum radio dx-8, spektrum t-1000 telemetry unit and want to use the spektrum optical RPM sensor but its wired to a JR type connector, can this be removed and simply wired to the small xbus type connector and plugged in without frying the system . spektrum apparently no longer sells a pick up for gas, only one for the .90 glo and for EP motors.
Has someone successfully done this and how'd you do it? Thanks. Brian

 

[orthobird]

so Brian, you want to use an RPM sensor that is optical, and not tapping into the pickup sensor? if this is the case, this is much easier to do. I, myself, tried multiple times to do it with the sensor, and it would never work for me on my DA's/ I eventually went with the optical sensors and they work great. I also had tried the spectrum infrared, and that was a mess. never worked.
Ok, i am going to contact someone from Spectrum to find the answer for you.

 

[49dimes]

OK, need some help.
Have spektrum radio dx-8, spektrum t-1000 telemetry unit and want to use the spektrum optical RPM sensor but its wired to a JR type connector, can this be removed and simply wired to the small xbus type connector and plugged in without frying the system . spektrum apparently no longer sells a pick up for gas, only one for the .90 glo and for EP motors.
Has someone successfully done this and how'd you do it? Thanks. Brian

From my understanding "muttdog" simply plugged the "available" male plug from the Y "adaptor" to the t-1000 using an "adaptor" he made. One end was a standard female connector and the other was a "rst" connector that plugged in to the t-1000.
So swapping your JR connector to a rst so it plugs in to your t-1000 should not be an issue. I would make an adaptor like "muttdog" did and plug every thing up that way. Make sure you get polarity and signal correct.
Plug it in where it says rpm.