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Cookie6000 wrote: ↑Sat Dec 19, 2020 3:54 pm Connect 12v+ to the battery, away she goes. Ref voltage climbs, gets to 4.3v and no further, motor keep running. I am guessing I am at the point now I need to change either R1 (currently 4k7) or R2 (currently 22k) to get the trigger point to about 3v, no?
20201219_153813.jpg

Did you get it to shut off?

Bigpie wrote: ↑Sat Jan 02, 2021 7:41 pm Anyone got any info on the vacuum sensor from a Corsa E?
Been looking for wiring diagrams for a few hours but not come up with anything. 3 pins

Pinout found by bobby_come_lately, added info to wiki.

johu wrote: ↑Sun Jan 03, 2021 8:54 am

Cookie6000 wrote: ↑Sat Dec 19, 2020 3:54 pm Connect 12v+ to the battery, away she goes. Ref voltage climbs, gets to 4.3v and no further, motor keep running. I am guessing I am at the point now I need to change either R1 (currently 4k7) or R2 (currently 22k) to get the trigger point to about 3v, no?
20201219_153813.jpg

Did you get it to shut off?

I didn't, no. I swapped R2 to 15k but no shut off up to 4.3v when it levels out. Yet to swap R1. Just need to dig around and find a 3k3 and test again.

johu wrote: ↑Sun Jan 03, 2021 8:54 am

Cookie6000 wrote: ↑Sat Dec 19, 2020 3:54 pm Connect 12v+ to the battery, away she goes. Ref voltage climbs, gets to 4.3v and no further, motor keep running. I am guessing I am at the point now I need to change either R1 (currently 4k7) or R2 (currently 22k) to get the trigger point to about 3v, no?
20201219_153813.jpg

Did you get it to shut off?

OK.
Finally got some time to play with this thing again. Here are the results

I kept R2 at 10k but swapped R1 for a 3.2k (instead of recommended 3.3k) which I found from another board.

Rigged everything up. As an aside, I had charged the vacuum 2 days previous and the ref voltage was still 4v so retention of vac pressure is spot on.
Purged vacuum so now ref voltage is 0.8v. Power the rig up, the pump runs and when it gets to 3.5v, the tone changes and the pump begins to slow down. 'Great!' I thought. Now we're onto a winner. Voltage slowly now increases from 3.5v to 3.8v... pump slowing further... then I notice a steady flow of smoke coming from the transistor. Argh! Disconnect power and then I notice the pump making a leaking sound...

So, prognosis. Wonder has the constant pressure on the pump over days not what it is used to. It may be designed to go to a 0 pressure vac rest state on engine shut down and this has caused damage to the diaphragm over the last 48 hours. Who knows. The primary problem of the puff of smoke is another I have no idea of. That's where I left it this morn. What you think @johu?

Ooh! I think the time constants are a bit different from what I'm used to. So the MOSFET went into linear region and heated up. Experiment failed. If the MOSFET is still good you can add a relay into the circuit and that will add the intended "digitalness". When destroyed let me refund
I think the pump is good, the vacuum is always preserved by the kickback valve for quite a long time.

Ah in fact I have one more left over in case your mosfet is toast and you want to try the relay route.

I'll report back later once I get a spare min with the relay to see if it's still operational. Have a few relays here to give it a try. Thanks johu

I've just tested the circuit board sent by Johu with the audi sensor and pump and all working perfectly so far.
Thanks Johu

Edit: After coming back to this as I'm now installing it for real I was a tad confused. I realised I have mine connected slightly differently to Fiachra but it still worked.
So after a bit of head scratching and metering It looks like the 12V pos is hard linked to the lead beside it so connecting either will work.

johu wrote: ↑Sun Jan 17, 2021 2:05 pm Ah in fact I have one more left over in case your mosfet is toast and you want to try the relay route.

Ah hell. I give up johu (pre emptive facepalm emoji). Where am I putting this relay in? I'm lockdown #3 brain fried. Tries a couple of different set ups and can't get it to work.

You put the relay where the pump used to be, i.e. 12V and the controller output.

johu wrote: ↑Thu Nov 19, 2020 8:15 pm Basically this. The MOSFET is strong enough to run the pump directly.

Hi Johu,
Are these populated boards for sale or were there only the few left?

All gone now but I can order some more on my next batch. Have also changed the layout to use cage clamps.

johu wrote: ↑Mon Feb 15, 2021 10:36 am All gone now but I can order some more on my next batch. Have also changed the layout to use cage clamps.

That would be great, I'll put my name down to buy one if you do get them

johu wrote: ↑Mon Feb 15, 2021 10:36 am All gone now but I can order some more on my next batch. Have also changed the layout to use cage clamps.

I’ll take one

johu wrote: ↑Mon Feb 15, 2021 10:36 am All gone now but I can order some more on my next batch. Have also changed the layout to use cage clamps.

I'm after one aswell for when their next in stock

Same!

Righty-ho

After a bit of a hiatus, I got stuck back in and decided to reverse out of the Bosch sensor cul-de-sac I was trying to traverse and ordered a VAG 036906051G sensor. I tried with Johu's help to get the Bosch sensor working but to no avail. I will get it working, just will sideline it for the moment until later. Really want to have it in there as an alternative that can work with Johu's unit to give more option for people.

So, back to the switch, I swapped the resistors back and added the transistor I bypassed, hooked it all up and it all worked a treat. Vac servo empty sits at 3.7v. When vacuum pump gets the system fully purged of air and we hit 0.7v, the pump shuts off immediately. Happy days. Time to swap hydro for air. Thanks for the patience Johnannes.

Very good!
Maybe I'll get one of these and conduct some experiments. I reckon rather than ditching one inversion stage it might be better to add another. I could then make a board that has two inputs, one for the Bosch and one for the VAG sensor.
On the picture it looks like you're running the pump directly over the mosfet, thats superb and just what I intended.

johu wrote: ↑Mon Feb 15, 2021 10:36 am All gone now but I can order some more on my next batch. Have also changed the layout to use cage clamps.

Hi johu,
Just checking if you have an idea when you'll have more of these?

Didn't make it on the last batch because I was in a rush as parts were dropping out of stock quickly... So next one in about 3-4 weeks. It will just support the negative going sensor, not the one that Cookie tested first.

Thanks for update johu, will keep an eye out for when you have them

I'm waiting to the next batch too

Will be ordering at JLC next week, so expect the module to be available in June

johu wrote: ↑Sun May 16, 2021 5:09 pm Will be ordering at JLC next week, so expect the module to be available in June

Cheers johu

Will these be on the openinverter shop? Still keen on one.