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Using a Hall sensor for Crankshaft Position Sensor

Sparkles

New member
Joined
Jun 29, 2017
I've got a B230 and M90 box from a 940 with a dog dish flywheel and I'm setting up a Speeduino for it. There's no CPS so I can either buy a new standard VR sensor (£30) and get a conditioner board for the speeduino (£20), or I can get the Cherry/ZF GS100701 Hall sensor (£35) which looks like it'll fit the M90 without any drama. Does anyone have experience with this sensor? https://uk.rs-online.com/web/p/hall-effect-sensors/7659321/
 
No direct experience with that particular sensor; but, as a general observation Hall sensors are easier to deal with than Vr sensors. No speed related issues and no need for conditioning circuits.
 
Those sensors are fine. They tend to break the wires right where they enter the sensor if you don't strain relieve them properly.
They also do not like a lot of heat, like mounting them on a valve cover to read a cam trigger wheel. But they should be fine for a block mount setup.
 
Thanks for the info and the link. I found what I think it's a clone of the Honeywell and it's really expensive. I've also only got about an inch of clearance above the gearbox so it would be tight. The Cherry sensor is probably a bit on the small side but I could just make a new bracket/grind the bracket.
 
I got the transmission off to install my new flywheel, and made a new bracket for the Cherry sensor. I had a quick Google but couldn't find out if the frequency of a Hall sensor given on its spec sheet is whole teeth or just edges. If it's edges then with the 60 tooth flywheel this 15kHz sensor would top out at 7500rpm, right?

Where are you putting the hall sensor? In the factory location? DIYautotune sells a few that are pretty reasonably priced... https://www.diyautotune.com/product/hall-effect-crankshaft-position-sensor/

I would prefer a more rugged looking sensor but those ones are too big, as I've got the engine right back against the Amazon's bulkhead, and the trans tunnel doesn't give enough room for anything to stick up so high.
 
You can still get the Honeywell 1GT101DC. I've found it in several places including allied electronics .


https://sensing.honeywell.com/1GT101DC-Speed-and-Direction-Sensors

Technical Specifications
Sensing Type Single Hall-effect
Housing Length 31,8 mm [1.25 in]
Operating Frequency 2 Hz to 25 kHz
Connection(s) 137 mm [5.4 in] Leads
UNSPSC Code 41111921
Housing Diameter 17,9 mm [0.70 in]
Supply Voltage 4.5 Vdc to 24 Vdc
Operating Temperature -40 ?C to 150 ?C [-40 ?F to 302 ?F]
Availability Global
UNSPSC Commodity 41111921 Speed Sensors

Please show me the math on your 7500 rpm. Somehow I dont think you'll be in the 15 Khz realm. I hope your not going to set this up without a scope anyway right?

Regards
Hubert.
 
The datasheet doesn't say explicitly, but I'd sure expect that the 15KHz is the tooth rate (i.e. 15000 rpm with a 60-tooth wheel). Odds are that the sensor will operate much faster, and that the datasheet is conservative. Make sure that the alignment is well centered and perpendicular. The recommended 1.5mm gap seems normal.

Your custom bracket is aluminum (or robust plastic), right? If it's steel, it can interfere or degrade the sensor magnetics.
 
With the honeywell the output of the sensor signal occurs when the edge of the tooth is apprx 1mm past the centerline of the sensor. The gap should be apprx 1mm between the sensor and disk tooth. Tooth height should be 8mm minimum. Tooth length minimum 8mm. Trigger wheel thickness min 8mm. What trigger angle does your ecu ask for or can it accept a range say from 45-112 degrees for instance?

Regards
Hubert
 
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The datasheet doesn't say explicitly, but I'd sure expect that the 15KHz is the tooth rate (i.e. 15000 rpm with a 60-tooth wheel). Odds are that the sensor will operate much faster, and that the datasheet is conservative. Make sure that the alignment is well centered and perpendicular. The recommended 1.5mm gap seems normal.

Your custom bracket is aluminum (or robust plastic), right? If it's steel, it can interfere or degrade the sensor magnetics.

330px-Slew-rate.svg.png


Red=desired Green=actual with effect of slew rate​


Im a bit confused 15000 rpm would only be 250 hz right? X 60 would be 4000 hz(4000 events per sec) or am I tripping? I think its signal remains fairly square until u start to get close to the limits of the devices slew rate then the square pulse train start distorting. I think the hall may have a better slew rate than the opto couple in a cas. If this is the case the Hall trigger should give you a more accurate signal plus its less drag on the intermediate shaft of a side mounted distributor. 15khz is the maximum operating frequency range . Something like this I imagine can handle nearly 900,000 rpm Most of them will have a min around 2 hz (120 rpm) . Maybe I'm tripping but this seems to be the correct math. The cherry should not run out at a Volvos redline If I'm correct. Someone else please check my calculations, but I think this is correct. Im not quite sure what an M90 is . I dont want to make the obvious assumption because I could be wrong. If it is the gearbox Im a bit lost.

Regards
Hubert
 
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Bob is correct. At 15,000 rpm a 60 tooth reluctor wheel would be spinning 250 times per second. 60 teeth covering 250 revolutions per second would create an output frequency of 15khz.

hk 40 said:
250 hz right? X 60 would be 4000
hk 40 said:
Someone else please check my calculations, but I think this is correct.

Nope. 250*60!=4000
 
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Huh?
250 revolutions per second (250 hertz) x 60 teeth is 4000 teeth per second ( 4000 hertz) multiplied by 60 for events per minute certainly isnt 15Khz its 240khz . So show me how you figure the output frequency will be 15000 hertz when u just calculated 4000 hertz right after you say nope... 15000 hertz is the maximum frequency that the sensor can accurately pick up if the maximum frequency it states it can pick up is 15khz . Its the same thing.

Hubert,
 
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hk 40 said:
250 revolutions per second show me how you figure the output frequency will be 15000 hertz

It’s pretty simple. 250*60=15000.

Might want to consult some of your super smart doctor friends on how to simple math.
 
Why consult them when I have smart asses like you ready to jump the moment i **** up? ;-) This is why you always ask for a math check. Thanks for correcting that. I don't know what the hell I was thinking there 250 x 60 = 4000 smh.... I guess stupidity is rubbing off in the phone world :-P

Regards
Hubert
 
Thanks for the compliment, but I’m really not that smart. I just know how to push 2 5 0 X 6 0 on the calculator and read the result after I push the = key.
 
Oh dont thank me too soon... I dont mean smart ass in that way. Don't get it twisted coz you stroke calculator keys better than me today :lol: I know you'd like to think otherwise but it was a careless error in keyboard marauding on my part. Enjoy it while it last. :cool:

Hubert
 
I’m not really enjoying anything. I think it’s really sad that someone who touts themselves as so intelligent spends three posts over the course of 4 hours defending the erroneous result of third grade level math.
 
Well by that metric I think its sadder to spend nearly 3 hours in 4 post to go out of your way to be nasty about it to correct a 3rd grade level math problem when all it requires is one in 60 seconds to say your math is wrong. 250 x 60 does not equal 4000.

Congratulations
 
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