Hi All,

I was referred to this board by one of your members.
I'm in the process of swapping a '98 Subaru EJ25 engine in my 1970 Bug.

I heard some where that it is possible to mock up a VSS using a HAL (?) switch ?
Anybodu got any good info on how o build this ? I think you need to mount a magnet on one of the driveshafts, and then the switch recognizes the rotation ?

Thanks,

Rob.

Look at this post

http://www.aussieveedubbers.com/forum/viewthread.php?tid=14906 

under the Subaru section, heaps of info :thumb

gidday Rob,
just today i sorted out my speed sensor I think! Reed switch in back of speedo so is triggered by manet which operates the needle. I got the clue on how to do it from this link:
http://www.smallcar.com/speeds.htm 
this seems to work fine (up to 135kph indicated but due to big wheels about 150 kph actual) which is as fast as i've been able to test it so far.
good luck
tonyg

Good stuff, thanks guys, I'll take a look at it.

Rob.

Check this post.
http://www.aussieveedubbers.com/forum/viewthread.php?tid=14864 

The ECU on my EJ20 expects to see the VSS pin connected to ground 4 times per wheel revolution. The Vanagon uses a reed switch and magnets in the speedo drive to achieve this. I think the same setup can be applied to the 1990's vintage EJ non-turbo Subarus.
Kombicol has adapted a Commodore optical VSS.
I plan on using a hall sensor and some magnets on the CV.

A friend has been with Telstra (Telecom) for >30 years and dealt with reed switches.

He responded to my question thus:

( He is NOT favourable disposed to my Transporter campervan, nor impressed by its performance.)

I would not use a reed relay. Consider this. An average car probably has a wheel rotation of 500 rpm. Therefore the Kraut Kramper would be roughly 250 rpm except when it is coming down the hill at West Ashgrove. You require 4 pulses per revolution. This means that the reed relay is operating at 1000 operations per minute.

This means the reed relay would operate 60,000,000 times per 1000 hours of use of the KK. I used to know the life of a reed relay because hundreds were used in an Ericsson telephone exchange. What I do know is that the quality of reed switches you would buy in Brisbane would be such that they probably have a life of only a few hundred thousand operations if you are very, very lucky.

FWIW

Dave

I've attached a file describing a Hall Effect VSS. The Allegro UGN3060KA sensor can be had as a free sample from the US manufacturer (even to here in Australia) if you only ask for 2. There are NO other parts other than magnets and cable.

This VSS works for me.

I wish I could recall who in the US sent me the circuit.

Dave

I have 5 peices of the new series hall unit comming from the USA in the next few days .


I would like to know your thoughts Jenny on proximity units like ( sick ) or PP units .High speed ? what to ask for ect , these are just look like a easy way of mounting > have a thread with two nuts pree wired better IP rating ect

like I said just your thoughts and part numbers> links ect Jenny seagull

Time for some math:
Using 4 pulses per wheel revolution and a 205/70R15 tyre. This has a diameter of about 0.668m and a circumferance of about 2.1m.
At 100km/hr you have about 47619 wheel rotations at 4 pulses/rotation = 190476 pulses in 3600 seconds = 52.94pulse/second or Hz
Your sensor needs to operate over the range of about 1Hz to 100Hz, which is not high speed.
In order for the sensor to act like the reed switch and connect the ECU pin to ground you will need one that has an open collector NPN transistor output. If you're keen then have a read of this http://www.allegromicro.com/techpub2/an/an27701.pdf 
There is also good info available at the Honeywell and ASSMtech web sites.
ASSEMtech have a fully encapsulated one (at least IP55) part PSS25S/30, available from Farnell. Note that the cheaper proximity sensors are actually only reed switches. The hall type ones start at about $50

nn[ Edited on 28-7-2005 by Jenny ]

I plan to use one of these mounted at an inner CV with a star shaped piece of metal attached to the CV. The points of the star would pass through the sensor. It is an On/Off hall effect device in a robust case, seems ideal.

http://www.jaycar.com.au/productView.asp?ID=ZD1900 

Only AU$20.

Thanks mike , I did ring jaycar about this one , told me no stock , rang again to day , yes we have stock now ! I off to get one .

Thanks for your post Jenny well done .I wish you lived down the road I am sure our projects would be running at the same time by now .

Yes thats correct Mike > long story but there samples comming from the USA , this takes 2 to 6 weeks .I need one now so purchased the jaycar unit today , what a shop ! have some great gear , I must get out my office more I did not know this place was even there , all types of kits you can make .

seagull
O I post you one when ( if ) they turn upnn[ Edited on 29-7-2005 by seagull ]

Just a thinking have a look at the subaru main pully , mine has 4 x 8mm holes spaced in it same size as the magnets I have , the unit from jaycar fits behind the pully bolted to the cam covers .

just an idea ? seagull

Neil if you drive it off the main pully you would be counting engine RPM, I thought you wanted to measure road speed? What are you using as your speedo on the trike? If you're using a normal motorcycle one with a mechanical cable drive off the front wheel then you may be better off buying that VDO part 412.009 and fitting it between the cable and your speedo. See catalogue page 66 & 67 herehttp://www.siemensvdo.com.au/files/2388_VDO%20CATALOGUE.pdf

The Jaycar sensor does not sound like an open collector type but, as I don't know the ECU circuit, it may still work.

The trigger disc for that type of sensor normally looks like an upside down small metal cup, with notches cut out of the lip. The lip with notches goes through the slot on the sensor making it switch, but the star shaped disc that you describe Mike should work too.
nn[ Edited on 29-7-2005 by Jenny ]nn[ Edited on 29-7-2005 by Jenny ]

Hi Jenny , yes its a motor bike speedo , I dont have any space to fit the vdo unit .
I found the Jaycar switches with magnets as well ( it did on the bench ) but I am machining a metal disk to day to do as mike is saying to fit to the cv flange.if this works I lazer cut some out .

cheers neil

My set up I doing this weekend , making and mounting of the metal starplate to cv .I be making the bracket for the hall unit tomorrow .

Mounted the plate to the back of the cv , I removed the three retaining plates ( stock vw ) .I will make an ajustable braket of the swing arm to mount the hall unit to .

the finished uint mounted and wired to the ecu

Seagull,

Looks good. My idea came to life and I didn't have to do anything! You've basically done what I planed to do. Only difference is I'm hoping to mount the star on the inner CV and make a bracket mounted under the clutch tube bracket to hold hall effect .

My car is only a few months away from needing this so I'm keen to hear how is goes.

Keep us informed Neil!
Thanks

Mike I found the small amout of play in the inner cv would collect the hall unit and smash it .

just hang in there as the samples are on there way , these may be better for a buggy set up .what I have will never see off road work , when you see it you will understand .

Neil

Mike the units arrived on friday ( 10 peices ) I load a photo soon .

Mike the units are ( ICs ) you would need to make the unit up

if some one would like to ( can do ) I will send these to them , may be we can sell them off & funds to the fourm ??

I have 10 peices here .

what's the manufacturer & part number?

Allegro Micro systems
Ic part number A1421LK

http://www.allegromicro.com 

Hope this helps Jenny

Any good to you Jenny ?

I can do some experimenting with them, but they are not the open collector output type, so I can't guarantee they'll work.

Any more happening on these?

no Mike its easy to get the one from jaycar , the other set up is lots of work .