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Has anyone tried Prosport Gauge senders?

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  • Has anyone tried Prosport Gauge senders?

    Has anyone tried the Prosport electric senders with a Fusion Brain?

    Do they work out of the box or not at all?


  • #2
    I have some more info...

    Oil pressure sender uses 0-5V, so I expect that to work ok on the FB with nothing else added.

    Oil temperature uses 32-925 oHms (on a 12V DC car system). I expect to have to use a resistor. Is that correct and which one?

    Is there a tutorial on how to wire up the resistor?


    • #3
      Yes. There's a similar thread here for air pressure senders:

      you'll want a resistor somewhere around 400 ohms. You'll need to generate the curvefit yourself.


      • #4
        And feed it from a voltage regulated circuit - eg, the FB.

        PS - Don't they provide linearity data?
        And 10 bar seems overkill for fuel pressure; even oil pressure!


        • #5
          Originally posted by OldSpark View Post
          And feed it from a voltage regulated circuit - eg, the FB.

          PS - Don't they provide linearity data?
          And 10 bar seems overkill for fuel pressure; even oil pressure!
          I see 6bar continuous and 8bar spikes on my SR20DET.


          • #6
            Originally posted by greenman100 View Post
            I see 6bar continuous and 8bar spikes on my SR20DET.
            Hopefully not for oil pressure LOL!

            How long do the spikes last?
            And I presume that isn't a 3-Bar system with 3-Bar continuous & up to 5-Bar boost?


            • #7
              So I have ordered my Fusion Brain and I have the Prosport senders. Now I'm feeling intimidated by putting this together. Expecting to do something stupid and fry the FB.

              Any help will be most welcome.

              The pressure sensor is three wire; 12V, Signal, Grnd.
              Signal range is 0-5V

              The temp sensor is two wire and came with no instructions. I'm assuming 12V and Grnd and the FB must measure the resistance between the two. Sensor should put out between 32 and 925 ohms.

              How should these be wired up and what tests should I do before pluging these into the FB?


              • #8
                wikipedia Voltage_divider

                Forget the Wiki padding - go straight to Resistive divider with the R1 & R2 diagram and that Vo = Vi x R2/(R1+R2).

                Also be aware that the voltage across a resistance is equal to the size of the resistor (Ohms) times the current thru it (Amps). In other works (or symbols...)...
                V = IR (V=Volts, I&R = Amps and Ohms else mA & kOhms.)

                So to convert resistance to voltage, add a resistor in series and place both across a voltage. (Though you might want a constant current source for the temp sensor if powering it from 5V and wanting a reasonable voltage swing: If R = 50 Ohms @ 5V, that's I = V/R = 5/50 = 0.1A. Power (Watts) =VI = 5 x 0.1 = 1/2W which might be getting a bit high... FYI: P=VI = VV/R = IIR by substituting V=IR into P=VI)

                And you might need to use the voltage divider to reduce sensor outputs to a suitable range (eg 0-5V to 0-4V etc).


                • #9
                  My assumption about the temp sensor was wrong. It uses signal and ground (not power and ground) so must be expecting power through the signal wire.


                  • #10
                    Yep - hence my resistive rant. (7 of 9 was was correct - Resistance is NOT futile.)

                    The temp sensor is a resistor - albeit temperature dependent - aka a thermistor.
                    Hence is is a simple passive two terminal device - usually packaged with case ground and single terminal, else electrically isolated 2-terminals.

                    You would have it as R2 in my previous post.


                    • #11
                      One of my problems is ... your talking way over my level of understanding. I've been sitting on the software side of things for too long and need a simple set of instructions as to what to do. I can see you're trying to be really helpful but I'm still no wiser.

                      Best to assume I am still in kindergarten on the hardware front, while on the software side I have a system that can not only read values from the car's CAN bus but also change the setup of the car without touching the normal controls.


                      • #12
                        Ok, your powered sensor puts out 0-5V so that should be okay. (But if you want to decrease the range from 0-5V to 0-4V etc, then the resistive/voltage divider applies.)

                        Your temp sender is a resistance. You do not measure resistance per se - you measure the voltage across it & current through it.
                        Instead of measuring the current (and voltage), we add a series resistor and merely measure the voltage across it....

                        Hence your temp sender needs another resistor placed in series and have a voltage applied....
                        Call the added resistor R1.
                        Call the temp sender R2.
                        Connect them between a voltage Vin.
                        You then measure the voltage across the temp sender R2 which is Vout. (See the Wiki voltage divider link as above.)

                        You need to calculate the R1 value based on (1) our temp sensor range, (2) the supply voltage Vin, & (3) your desired output voltage range Vout.

                        Be aware that Vin needs to be regulated. Hence you might use another regulated source or the FB's 5V etc.
                        The problem is that you may want a good voltage range across the temp sender which means a higher voltage supply. This is to make the added resistor as large as possible to reduce the current. (Increased current means more load on the supply (eg, FB) as well as higher resistor wattage ratings.) An alternative is to use a constant current source (typically 2 transistors and a resistor or 2).

                        For comparison, many vehicle temp gauges are supplied by an 8V regulated supply.

                        Though the above sounds complex, it's just "one bit at a time". I've given you the full byte (in a long-word).
                        It is application of one main thing - Ohm's Law (V=IR).
                        Also a bit of power ratings (P=VI) and understanding basic circuit theory that series voltages add up (to the supply voltage) and the current flowing through a path is equal through each component (which is really Ohms Law V=IR).

                        It's an iterative design. Set your desired temp range (and hence resistance range) and what voltage that should correspond to for your FB.
                        You then iterate R1 based in Vin supply voltage and source.....
                        ... and then, more Chinese take-away programming tricks....


                        • #13
                          Here a couple of threads to look at. I was having a hard time understanding voltage dividers also and these were clear enough that even I could understand them.

                          The third link is an online voltage divider calculator that will help you find the correct resistor size.






                          • #14
                            Thanks to both of you.


                            • #15
                              For the temp sensor ...

                              Using a 400ohm resistor I will get signal voltage in the range 0.37V - 3.491V
                              Connect the 5V out on the FB to one side of the resistor. Connect the other side of the resistor to one of the sensor wires. Connect the other sensor wire to the FB signal. Connect the FB Ground to ground.

                              For the pressure sensor...

                              Connect battery to 12V wire on the sensor
                              Connect signal wire on sensor to FB signal
                              Connect the Ground on the sensor to ground
                              Connect the Ground on the FB to ground