ABS sensors

Discuss which Sensors work best with these ECUs and share how you are using inputs and outputs
Jon K
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Re: ABS sensors

Post by Jon K »

Ok - yep. A lot, lot different than the older cars. From what you can tell, does it read the side of the tone wheel or does it read the face. Ie., does it read the teeth perpendicularly or does it read it from the direction its inserted?
1992 700RWHP Pump Gas BMW
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mefmotorsport
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Re: ABS sensors

Post by mefmotorsport »

cant tell as you cant see any teeth. I think it reads them from the face, I tries a small VR sensor offered up to the face and I get a low level sine wave output when rotating the hub but it's very hard to get any sensible or constant speed when trying to hold the sensor, the upright and rotate the hub face!

I just ordered up a hall effect sensor from RS components:

http://docs-europe.electrocomponents.co ... 02e30e.pdf


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It will be here tomorrow so I'll fit it and see what comes out. It has an M12 threaded body so it should be easily adaptable to fit the BMW upright and reach the face of the wheel bearing where the ring is embedded.

Martin
Jon K
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Re: ABS sensors

Post by Jon K »

Sweet - if you need to get into any weird angles or what not, check this thread out:

http://msextra.com/forums/viewtopic.php?f=131&t=41370
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MarcoV6T
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Re: ABS sensors

Post by MarcoV6T »

Martin,
if the ABS sensor has only two wires, then it must be a VR sensor, a Hall sensor has three wires.

The main reason ABS sensors are typically VR sensors, is because these are ‘dumb’ sensors, and can withstand higher temperatures than Hall sensors(built-in electronics), the sensor you mentioned above, is rated max 75°C, it won’t last long placed near a break disk.

If you measure infinite resistance, then probably your ABS sensor is dead.
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mefmotorsport
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Re: ABS sensors

Post by mefmotorsport »

MarcoV6T wrote:Martin,
if the ABS sensor has only two wires, then it must be a VR sensor, a Hall sensor has three wires.

The main reason ABS sensors are typically VR sensors, is because these are ‘dumb’ sensors, and can withstand higher temperatures than Hall sensors(built-in electronics), the sensor you mentioned above, is rated max 75°C, it won’t last long placed near a break disk.

If you measure infinite resistance, then probably your ABS sensor is dead.
OK, I'm sorry but you're completely wrong here, I've proved that they are 2 wire active devices, please study the information from the data sheet

http://www.datasheetcatalog.org/datashe ... 57_pra.pdf

They are very clever and complicated advanced devices that not only have 3 hall effect devices but can measure the direction of rotation and also put out pulses when the wheel is stationary! (which is of no use to the DTA for launch control). Ive actually set one up on my desk with 12v power and a 75 ohm load resistor and looked at the pulse train on the scope. I have maybe 10 of these and they cant all be open circuit! No use to us whatsoever!


Martin
MarcoV6T
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Re: ABS sensors

Post by MarcoV6T »

mefmotorsport wrote:OK, I'm sorry but you're completely wrong here, I've proved that they are 2 wire active devices, please study the information from the data sheet
Well, not completely, but I admit that it’s the first time I’ve seen those kind of sensors(transducers), anyway, these have a working temperature of -45° to 150°C(190° max), the one you’ve ordered are rated 75°C max.
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mefmotorsport
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Re: ABS sensors

Post by mefmotorsport »

OK, yes, the working temperature is no good I agree, OK with some magnets on a propshaft etc.... but no good on the back of a wheel bearing! I think this is actually the one that gets supplied with some of the trip meters on the market.

Anyway that hall effect sensor doesn't work on my wheel bearing, I suspect that there is insufficient magnetism in the magnet thats inside the wheel bearing, I cant even get a screwdriver to stick to it although I know it's there, I can see small bits of steel swaft that move about as I rotate the hub. Maybe there's enough for those active ones as they have internal amps etc..

I have just tried a small VR sensor and can only get a signal of around 5mv p-p on my oscilloscop, burried down in the noise.

Maybe I am never going to be able to use the original sensor position, I might have to fabricate a bracket and sense off the back of the wheel bolts, I was just trying to avoid doing this!

Martin
razzor
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Re: ABS sensors

Post by razzor »

I can understanding using these sensors for custom applications but what would be the disadvantage of using oem sensors in the original application ?
stevieturbo
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Re: ABS sensors

Post by stevieturbo »

Can you persuade Allan to make the DTA accept the OEM signal ? Is the hardware able to ?
razzor
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Re: ABS sensors

Post by razzor »

so i take it the oem sensors dont work properly with the DTA ?
On my VR6 would i need to buy another sensor ?
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