Beiträge von Rudolf

    Some details about right installation/connection:

    1. On image you can see, how to connect all cables, if there is something unclear, not exact, please tell me!

    2. On second image you can see, that engine turned little bit, to change position of hall sensor, immediately is LED on device ON.

    It is really helpful, to have immediately information, that signal was passed to SparkSwitch Pro. In case when LED stay off, not blinking, when you rotate engine, then something went wrong, and signal is not passed. But I hope that never happen :-)

    3. Pinout

    If somebody will need help, please do not hesitate contact me immediately, also share please your experiences with new device!

    For all users of multi-cylinder engines, please have look into my post in thread SparkSwitch PRO and multi cylinder engines

    Couple of pilots are using this new device developed especially for SparkSwitch Pro, me too (first one, prototype :-)) and all are really satisfied with possibility to measure MIN/MAX temperatures on cylinders, using SparkSwitch Pro directly. I'm using this device also for one cylinder engine, with 2 sensors in different positions inside cowl. It's helpful for me, to be sure that engine is well cooled.

    Hallo All,

    new version is ready, on pictures you can see differences in size (new version is smaller), and new version has LED indicator of functionality, showing (blinking) status - sending pulses into SparkSwitch Pro:

    1. Here you can see both, installed old version, but connected new version, SparkSwitch Pro is ON (LED on fuselage)

    2. Engine is sending RPM info to SparkSwitch Pro (on device LED is ON)

    3. Little bit more rpm to be able see it on transceiver telemetry:

    All, whom I sent old version, I will send gratis new also, not need pay anything :-)

    Have a fun



    I would like inform all pilots, interesting into measuring of temperature for multi-cylinder engines, using SparkSwitch Pro, now is available device, whose is available to send into SparkSwitch Pro Minimum/Maximum/Average temperature of 2/3/4/5 cylinders. Means, this device is connected using patch lead to SparkSwitch Pro Temperature sensor port, and all sensors (available together with the device, cable length 40cm) for each one cylinder are connected into device. Device is controlled by one PWM channel, 3 position switch 0-Avg, 100-Max, -100-Min temperature.

    Dimensions: 46x22mm

    Wight: 10g without sensors

    Inputs: 1xPWM, 2 up to 5 temperature sensors

    Output: 1x output to SparkSwitch Pro temperature sensor port, using two wire patch lead

    Voltage source: Rx/PWM Channel, from 3.3V up to 8.4V

    Prototype was tested with MOKI 400cc 5 cylinder engine in the flight.

    In case, if you are interesting into it, let me know, device will be available from March 2, 2019 :-)

    have a nice evening


    Hello Kjell,

    I saw right now your post, I'm interesting about all related to SparkSwitch Pro. I know, that it is little bit late :-) maybe you resolved your problem using nice device from CB Elektronics, but for one my colleague I developed small device for MOKI 400cc radial 5 cylinder engine. This device is sending maximal temperature from all 5 sensors, and you can switch using one channel to send average temperature. Device has 7 connectors, one input (plugged into SparkSwitch Pro into temperature port), 5 connectors for each one cylinder, connected 5 temperature sensors, and one for PWM signal to switching maximal/average temperature (without using this port the default value is max). Colleague is satisfied, getting right information about the temperature and told me, that he is using mainly maximal temperature information, its important for him, and getting only one temperature info on transmitter screen makes it more readable.

    have a nice day


    yes, indeed, not only US as I can see :-)

    Colleague after yesterday's tests ordered 2 SparkSwitch Pro and he will use it with DA engines. He is using lot of years only DA (I'm using always OS MAX, GT33 or GT60, and now is new GT120), because is absolutely satisfied with DA.

    Salut All,

    because I'm not very patient guy, right now we did the test with colleague on balcony :-D

    Extra 330SC, DA-50.

    Initialy testing old setup with normal killswitch. Measuring full range from idle to 7380rpm using optical rpm meter.

    Replaced old killswitch with SparkSwitch Pro, wiring all properly (without temperature sensor), programming telemetry on 18SZ, on third flip started, full range of rpm's as in the past without any issue!

    It's working as I expected.

    Without any change on device :-) No impacts to ignition timing, absolutely separated signals.

    Have a great day, I'm satisfied!


    hallo Richard,

    thanks for warning, but, to be honest, I expected that and initially I designed something like instrumentation amplifier between input signal and optocoupler, therefore I can say, that I will not harm signal passing to ignitor's amplifier.

    But, we will see. All is solvable :-)


    Hi Richard,

    today I'm working from home :-) therefore I had time for small experiment, I was really curious about passing some weak, analog pulse, with amplitude from 0.8V to 6V.

    Threshold is min 0.8V without any changes, in case when we will need lower voltage, I can update resistor in amplifier. But I got nice output pulses at device output.

    DA ignitors are working from 4.8V to 6V, but I'm not sure about the sensor signal, as I mentioned, I will let you know at Thursday, but from my point of view, it should be work. If you have some another doubts, please tell me, to be prepared for another possible issues at Thursday, because I never used DA.




    Hi, signal from sensor (any) is modified to clear pulse and passed into SparkSwitch. Of course I not tested DA, but as can I see in documentation, it should be work.

    Let me test it, one colleague is using DA-50 engine, we will test it at Thursday. Will let you know.

    For all Ignitors without tacho output we can use small device, developed initially for OS MAX Ignitors, but usable for all other ignitors without tacho output.

    This device with dimensions 25x17mm, weight less than 5g contains four connectors:

    1. connect input from Hall (or other type of sensor, for instance DA sensors are not a Hall type) sensor on engine

    2. connect output from ignitor, normally connected to Hall sensor

    3. connect input lead from ignitor, normally used for power supply of ignitor, does not matter what voltage, it's working from 1.1V up to 3 cells full voltage

    4. connect to SparkSwitch Pro

    If is anybody is interested in it, send me private message please.

    On the picture you can see:

    1. Left side - device without shrink tube covering, to be able have look to implementation, PCB is two side, well shielding, used all SMD components excluding mosfet

    2. Right side - device covered, this covering is safe, do not need any metal box, easy use flexible strips for fixing, ideal position is near to ignitor

    UPDATE !!!

    New version of device, information inside this thread, at the bottom :-)

    Hallo Kjell,

    if you will have problems with amplitude of signal from ignitor, you can use one newly developed device, originally developed for OS MAX ignitors. This device modify input signal from min 1.2 V to 5.9 V. Both sides are isolated by optocoupler, therefore it's safe if you are using different supply for hall sensor, directly from ignitor.

    Have look into Spark Switch Pro and OS GF-30 RPM

    Have a great day



    you can use SparkSwitch Pro directly connected to Rx in two ways:

    1. PWM channel connected to SparkSwitch

    2. Using S.Bus2 (Futaba)

    I do not know Android version, I hope that it is the same as iOS :-) You can simply setup SparkSwitch as you want, Be aware about setup of voltage! When you are using full 2 cell voltage, please disable internal regulator in SparkSwitch Pro - in setup.

    Hope it will help

    Have a nice day


    Hi Jurgen, it's working in the fly properly and it's really stable, great to have rpm telemetry for OS engines :-) I tested new device accessory in Edge V3 78" with OS MAX GT33 engine. I reworked device, because initial version had two and two connectors on opposite sides, means it was unable to use shrink tube for some isolation, I thought that I will build some small metal box but it's really not good idea. Therefore I reworked PCB and now new version is 25x17mm and all 4th connectors are in one line, therefore not needed any box, used easy and perfect isolation with transparent shrink tube. Device is working in whole range of power supply, from 4.8V to 8.4V, not depend on voltage setup, max 2cells of LiPo or LIOn of course.

    Summary: It's ready and properly working with PB SparkSwitch Pro for full voltage range (5.9V using internal regulator or over 8.4V). Weight 5g, dimensions 17x25 mm, covered by transparent heat shrink tube. On picture is version without shrink tube. On prototype I used black shrink tube, now waiting for delivery of transparent :-)

    Connectors from left to right: 1-Spark Switch, 2-Input to Ignitor (Power Supply), 3-Output from Ignitor, 4-Hall sensor on engine. Spark Switch can be configured for 5.9V or full 3 cell voltage.

    Another one will be installed in Extra 330LX 92" with OS MAX 60GT.

    hallo, good evening. Yes, indeed, 'issue' with OS IG resolved. All tests on the ground done, Now I'm waiting for some acceptable weather, without snowing, to be able 'maiden fly' with the new accessory.

    Regarding price, if you're interesting for that, I will send you accessory by post, I would like only post fees back.