Inverting Tps Signal

[sub205 5]

Yesterday i created a small circuit for inverting the TPS signal of the MM-loom. the TPS signal is going high -> low, but megasquirt need low -> high.

 

needs 1 opamp, 4 resistors and 1 capacitor. biggest problem: because of the elements in the opamp, the signal is slightly lower. i had to tune the resistors to get it right, otherwise it could be cutted at peaks.

 

perhaps someone finds this useful... see for yourself:

 

[DrSarty 90 1 Cars]

I'm confused here.

 

Don't you mean Crank Angle Sensor (CAS), also known as Crank Postition (CPS)* or even just Speed Sensor rather than TPS (Throttle Position Sensor)?

 

A TPS just gives a 0-5v DC return.

 

A CAS gives an AC signal back to the ECU and can be reversed just by swapping the two signal wires. There is a shield around the positive signal wire which does nothing other than be grounded at the ECU end; it doesn't carry a signal.

 

I'm wondering if you could be meaning creating a square wave for Megasquirt?

 

Sorry for the questions but use of 'TPS' here doesn't quite make sense, and even the signal from that can be reversed by swapping two wires over if it's wired in reverse.

 

Is there another abbreviation for CAS I don't know about? If it's TPS in German then I apologise.

 

*Also known as VR (Variable Reluctance Sensor)

[Tom Fenton 1,525]

If you are truly inverting the throttle pot signal, all you needed to do was swap the 0v and +5v wires over, and leave the wiper wire in the same place??

[sub205 5]

If you are truly inverting the throttle pot signal, all you needed to do was swap the 0v and +5v wires over, and leave the wiper wire in the same place??

its the tps, throttle position sensor

and the reason why i want it inverted is to make my megasquirt really plug&play and 1:1 swappable with the original ecu without changing pins every time!

[DrSarty 90 1 Cars]

OK then.

 

2 bullet connectors would work for me.

[Tom Fenton 1,525]

If you are that bothered about swapping between different ECU's then a short adaptor loom with 2 off 3 pin Junior timer plugs (male and female) to add in for the one ECU and remove for the other would do it for me.

 

But I have to say, once you've fitted an aftermarket ECU I don't understand why you'd wish to go back to standard anyhow.

[sub205 5]

If you are that bothered about swapping between different ECU's then a short adaptor loom with 2 off 3 pin Junior timer plugs (male and female) to add in for the one ECU and remove for the other would do it for me.

 

But I have to say, once you've fitted an aftermarket ECU I don't understand why you'd wish to go back to standard anyhow.

because i need the car nearly every day. and in the beginning of mapping i need the option to swap back to stock, just if anything goes wrong and i have to drive longer distances. i like electronics and have the equipment, so why not using it and build a simple opamp-based inverter for analog signals?

[Galifrey 1]

because i need the car nearly every day. and in the beginning of mapping i need the option to swap back to stock, just if anything goes wrong and i have to drive longer distances. i like electronics and have the equipment, so why not using it and build a simple opamp-based inverter for analog signals?

 

 

Do you know the expression "sledgehammer to crack a nut"?

[sub205 5]

Do you know the expression "sledgehammer to crack a nut"?

in this case i would rather prefer a nail file

[Veero 1]

Sorry to be tardy to the party, wouldn't it be easier still to just get a Bosch TPS off an Alfa Romeo TB? I believe the mechanism is identical but just mirrored, as the TPS fits onto the TB on the other end of the spindle, si fitting it onto the Mi16 TB would effectively reverse the action of the Mi one.

[pug_ham 240 3 Cars]

wouldn't it be easier still to just get a Bosch TPS off an Alfa Romeo TB? I believe the mechanism is identical but just mirrored

This is very probable because when I first fitted the MP3.1 to my car using a Bosch TPS I found when I went to WOT the car died (causing a scarey over taking moment) & I had no idea why.

 

When I took it for maopping it turned out that the TPS was switching to the idle map when I went to WOT so we swapped the wires round until it was right.

 

Graham.

[Henry Yorke 269 3 Cars]

My MP3.2 has a Vauxhall TPS on the standard 1.9 throttle body for this reason I believe