Posts by Papatrey

    I don't think there is anything wrong, because everything else works (Current, voltage, capacity, temperature). The fact I'm getting telemetry says I've connected the telemetry correctly. The fact that the ignition shuts off and turns on to start the engine means the connection from the rx to SparkSwitch is correct. The battery is in the right place since I'm getting current and voltage displayed. And the light comes on (once I reversed the polarity) when the radio switch is in the right position. The ignition correction is correct because the engine runs. You confirmed that my description of my connection to the RPM Sensor is correct (connected to Y into ignition). That accounts for every connection.

    BUT.....I did have success using Rudolf's recommendation to remove the RPM Sensor and connect the signal wire from the halls sensor to ignition slot using a Y connector. Just for those who may be looking for help, I had to select rpm sensor not Speed Sensor as shown in Futaba instructions in this forum. Then I had to select the brushless motor option and set the poles to 2 (corresponding to blades on prop) to get the correct RPM reading. Happy to have it working on the DA35.

    I do appreciate everyone's help. I may incorporate it on the DA70 and DA120 in the future once I read that people are having success installing the RPM Sensor on DA with Futaba.


    Do you have any thoughts of why this isn't working with the RPM Sensor?

    Do you know of anyone who has successfully used the RPM Sensor, Futuba, and DA engine? As Rudolf stated, he was successful with a DA70, but not using this particular RPM Sensor.

    Thank you,

    Thanks again for your input.

    Just to be sure I understand. I have the ignition slot with Y cable attached. I have connected the lead with signal wire removed to that Y cable and to the ignition as before. See picture.

    To the Y that is shown in the picture, you said to run the signal wire from that to the Y that is connected to the ignition slot on the SparkSwitch (the RPM Sensor was previously plugged into that Y cable). Correct?

    The other question is do I only use the signal wire or does the signal wire need the ground also?

    Once I have these answers I will give it a try.



    There is no reason to need the signal wire to be connected to the ignition for this system to work, correct?

    If that's the case, due you think I have a defective RPM Sensor. Everything else on the SparkSwitch is working perfectly.

    A little more information on removing the signal wire from the ignition.

    When I couldn't get the engine to run, I put the TechAero back on and the engine fired right up. Thinking the voltage wasn't getting to the ignition, I checked it with a meter and determined it was getting 5.9V from the SparkSwitch. I then thought it could be the Y cable so I plugged the ignition straight into the SparkSwitch (RPM Sensor not connected) and the engine ran.

    I then replaced the Y cable with a new cable and the engine wouldn't run with the RPM Sensor connected. I then disconnected the RPM Sensor from the Y cable and the engine ran fine. At that point I knew it was something to do with the RPM Sensor being connected to the Y cable. Figuring the RPM Sensor's signal cable was carrying something from the sensor to the SparkSwitch, I decided to remove the signal wire from the RPM Sensor lead. The engine ran fine with that lead removed.

    However, since I'm confident that signal from the RPM Sensor needs to go so the SparkSwitch, I then put it back in and removed the signal wire from the ignition input. Now I am just putting power to the ignition from that wire, but there isn't any signal wire connected to the ignition. I'm not sure why the signal would prevent the ignition system from working, but it does.

    Based upon that, I am confident there is a signal on the signal wire coming from the RPM Sensor (that is what was preventing the ignition from working). To me the question is why isn't that signal being properly used by the SparkSwitch to display the RPM.

    I have the supplied Y cable connected to the Ignition socket on the SparkSwitch. I have an extension connected to the Y cable that goes to the input of the ignition. As I said in my first post, I had to remove the signal wire from the ignition because the engine would not run with the signal wire connected to the ignition. In other words, I am simply applying power from the Sparkswitch Pro to the ignition. I have read the voltage and it is 5.9v as set in the Power Terminal program.

    I have the RPM sensor connected to that same Y cable as the ignition. So the ignition and the RPM sensor are connected to the Y cable that is connected to the Ignition socket on the SparkSwitch Pro.

    Thanks for taking the time to talk this through.


    I have everything working but the RPM sensor....which is the primary reason I want to use it. FYI...I updated it to Firmware 4.0 which is the latest and I had to reverse the polarity for the bulb to work.


    At first, I couldn't get the engine to run with the SparkSwitch Pro as the input. I knew I had voltage going to the ignition, but it wouldn't run. I noticed the only difference with the TechAero and the SparkSwitch Pro was that I had a signal wire also connected to the ignition box. I removed the signal wire and it fired right up.


    As you can see in the attachment, everything else is working fine. The temp is on the next page but it is also working. I'm drawing 0.1 amps, the battery is at 7.8v and I've used 24mah up to that point.


    I've also attached a picture of the wire wrapped around the ignition wire.


    Based on everything I've read, it appears that there is an issue with either the pickup or the SparkSwitch Pro as far as using it with a DA engine goes.


    My questions are:

    1. Any suggestions on what I can do different?

    2. Is Powerbox looking into this issue since there are several threads that indicate others are having the same problem with the DA70 and DA120.


    Thank you!!




    I won a SparkSwitch Pro at a fly-in this weekend and have done some research but can't find a specific answer to this question.

    I have a DA35, DA70, and DA120 and I use a Futaba 18SZ radio. I understand that I need the Teleconverter S-BUS2 to get telemetry with a Futaba radio.

    My question is this: Does the PBS-RPM device work with DA engines and interface with the Futaba radios via the Teleconverter? The product description states it can be used with Jeti, M-Link and HoTT , but there is no mention of Futaba.

    Thank you,