Chip

iTrader: (3)

Aside from me needing to know for this project, I think a lot of people would find all that info interesting

I suspect 2 or 3 of the wires will just be a TPS to determine where its sat currently for the ECU

NEEDFORSPEED

lol yes there are defo i forgot about that! i think on the audi one theres a moniter wire il find out tomo tho im interested too!i never got further then buying it and was going to end up costing far too much!!

NEEDFORSPEED

id look at the size now but torch is in the van and its dark! im sure its about three inch tho thats why i chose it

Chip

iTrader: (3)

Well if its 3" and you have a wiring diagram for it that can allow me to open and close it easily, then its sold

NEEDFORSPEED

sure youl just have to work out some decent size resistors to get the 2 voltages whatever theyl be

Chip

iTrader: (3)

I suspect one will be zero, so thats pretty easy, and anyway not a problem on the other one, i'll just use a variable resistor initially, then turn it till it goes where i want, measure the resistance at that point, and install a fixed resistor of a similar value to that.

NEEDFORSPEED

theres 2 variables as far as i know for safety so if one side goes down your not left without throttle but with half and just puts light on. get some good resistors too big ceramic ones as youl be using a bit of current i would of thought

richm

Chip,
The Audi/VW 20V 1.8T ones are 2-wire motors and spring return to closed, I'm pretty sure they are voltage driven, but not 100% certain i'm afraid without double checking..
The housing also incorporates a twin-track feedback potentiometer.

6 wires total - 2 for the motor and 4 for the feedback pot (common supply and ground to both tracks and seperate wipers)

Chip

iTrader: (3)

Thanks for that richm, sounds quite promising if its just a fixed voltage not a PVM that holds it open.

richm

even though it's a 2-wire motor, it could still be a PWM voltage signal - imagine the vauxhall Bosch rotary idle air valve, exactly the same principle - sprung return and 2-wire pwm voltage to vary the opening.


*** EDIT to add a bit... ***
But when all is said and done, all the PWM does is varies the "average" voltage that the motor armature sees, it's just an easier mechanism to control electronically and doesn't generate as much heat in the switching device. You can experiment with a variable voltage supply (your variable resistor and a battery if you like lol) to establish what is needed to open the butterfly by the amount you need, even if it is a "pwm" driven motor in normal OEM applications

Chip

iTrader: (3)

Agreed.

TBH its not the end of the world if I have to make a little flip-flop box to send out a 90% PWM 20hz signal or similar I guess.

Id need a working car to stick on an osciliscope though to determine what it was doing in order to know what i need to reproduce.

richm

chip, see my edit in previous post

foreigneRS

exactly. if it is PWM (don't know what PVM is what you keep writing ) then 100% duty cycle is just a DC voltage anyway

Chip

iTrader: (3)

PVM was just a typo, you'll see ive used both.

Pulse Width Modulated is what I was of course referring to.

The danger of a signal going DC of course is that the motor then stops being a motor and starts being a heater, which is obviously potentially catastrophic if the current draw is allowed to be too high.

NEEDFORSPEED

normally i work somewhere where there is a vw or audi every single day but as sods law states i havnt as ive wanted too so i have no info for you yet!!

Chip

iTrader: (3)

LOL

No worries mate.

I think I may have found an answer now anyway, V6 Cavalier Traction control Thorttle looks perfect for what im after and Ive just realised Ive got one here anyway, although Ive yet to figure out how it works.

richm

not at all Chip...
the motor is always going to be a heater - provided the power rating of the motor isn't exceeded it won't care if the supply is DC or PWM or whatever else. For example, as mentioned above, a 12V peak 100% duty cycle PWM drive signal IS 12V DC
You just have to establish what DC voltage is required to drive it fully open and not exceed that.

Chip

iTrader: (3)

Its not that straightforward in terms of it always being a heater.

when its a PWM signal it gets time to cool between the pulses and when its moving it uses the energy up that way rather than as heat.

Get an injector, or a speaker, or just about anything else with a coil in it that normal takes a variable input and moves and give it a straight DC signal and you'll get problems potentially.
Normally these things dont ever see a fixed dc signal aka 100% PWM
You can kill a 1000W speaker with a very small amount of current through it DC for example.

richm

Chip - sorry, just not true in the case of a PWM driven motor in this kind of application, as it doesn't actually "move" in the normal sense, it is merely an armature that provides torque to move the throttle plate to a required position..
The armature requires an amount of power to move it to a given position, power is the important factor here. It doesn't matter if it's PWM of suitable duty cycle and peak voltage, or DC of a suitable level so long as it provides the same power

The device may indeed not require a 100% duty cycle at the chosen supply voltage to provide max torque, I used that as an easy to understand specific condition to demonstrate the equivalence of a DC supply voltage to a PWM one.

A speaker is not an equivalent example, as it is an AC operated device, which is far from being a pure resistive load, and that is essentially always moving, so generating considerable back-emf in the process.

Chip

iTrader: (3)

Ok RichM, thanks for the input, fingers crossed you are correct about me being wrong that a continuous voltage could burn it out, as that will make it a piece of piss to wire in if thats the case and I will have been making a fuss about nothing

richm

I hope I'm right too Chip.. or I wasted 3 years university and 30 years doing electronic design

Obviously the crucial part is establishing what equivalent DC voltage is required to open the throttle fully and don't exceed that. Clearly if the system normally applies for example say 50% duty cycle of 12V peak voltage as maximum drive signal, then chances are just bunging 12V dc on there will burn it out as you say, - whereas 5 or 6V dc will do the same job quite safely.

Chip

iTrader: (3)

Cool, I will just start upping the voltage till the fucker moves then I guess, lol

Any idea what sort of resistance I should see across the two relevent pins, as I have 5 to choose from

richm

i'm guessing as I've never investigated, but I'd expect in the region of tens of ohms. The feedback potentiometers will be much higher, but be aware that you may find a small resistance between the wiper(s) and the end of the pot track(s), although they are easy to spot as they will change as you manually open the throttle plate.
Another test that may confirm the pair that you decide is the motor - measure the voltage between the wires you think whilst you manually move the plate - you should be able to measure the back-emf voltage generated when you physically move the motor via the plate.
Don't forget that it will be polarity sensitive so you will need to apply the voltage the right way round to drive the plate open, the wrong way will just press it into the stop

If it's a VAG 1.8T one you are trying - the wiring diagram suggests pins 3&5 of the 6 pin connector, 3 probably being positive.

Chip

iTrader: (3)

Its a vectra V6 traction control body (its mega compact and a good diameter) and thanks VERY much for the tips, that all makes perfect sense