Need a high-temp gear tooth(hall) sensor
Need a high-temp gear tooth(hall) sensor
(OP)
Aloha,
Well, I'm working on a traction control system; however, the space constraints are very tight (trying to get brakes and speed sensor to fit inside of a 10" rim) thus the tone ring for the speed sensor was integrated with the rear disks. The problem now is excessive heat generation under heavy breaking is causing the speeds sensors to flake out. I know Honeywell makes these great little 3/8" long hall sensors that can withstand 400 degrees, but cost is a concern and at $200+ for a single sensor, the cost may out weigh the benefits of traction control.
So with that all in mind, does anyone know of a small hall speed sensor which doesn't require an external magnet that can withstand temps of 200C or greater in a cost effective package? Ideally, the axial length needs to be less than 1.25".
Thanks for any input in advance.
Well, I'm working on a traction control system; however, the space constraints are very tight (trying to get brakes and speed sensor to fit inside of a 10" rim) thus the tone ring for the speed sensor was integrated with the rear disks. The problem now is excessive heat generation under heavy breaking is causing the speeds sensors to flake out. I know Honeywell makes these great little 3/8" long hall sensors that can withstand 400 degrees, but cost is a concern and at $200+ for a single sensor, the cost may out weigh the benefits of traction control.
So with that all in mind, does anyone know of a small hall speed sensor which doesn't require an external magnet that can withstand temps of 200C or greater in a cost effective package? Ideally, the axial length needs to be less than 1.25".
Thanks for any input in advance.





RE: Need a high-temp gear tooth(hall) sensor
When the tone wheel gets hot enough to screw up the Hall sensor, it's got to be plenty hot enough to be visible to any old IR sensor.
So use an analog IR sensor, e.g. photodiode, to keep track of the tone wheel temperature, and when it gets above some threshold, derive the tone wheel signal from the IR sensor instead of the Hall sensor.
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA
RE: Need a high-temp gear tooth(hall) sensor
Robert
RE: Need a high-temp gear tooth(hall) sensor
I remain,
The Old Soldering Gunslinger
RE: Need a high-temp gear tooth(hall) sensor
What I'm proposing is not an optical chopper, but just the detector half, which by the way should be aimed to look at something relatively cool when there's no tooth in its field of view.
Of course, putting the tone ring _anywhere_ else would be better than building it into the brake rotor, but the design was already screwed up when we got here.
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA
RE: Need a high-temp gear tooth(hall) sensor
I can offer a suggestion; the toothed wheel operating as a photo interupter with the use of a glass fibre light pipe to transmit the tooth signal to a remote located optosensor/source.
regards, Robert
RE: Need a high-temp gear tooth(hall) sensor
Ron
RE: Need a high-temp gear tooth(hall) sensor
VRS sensors were researched but most of the units that met the requirements of small axial length and high temp operation ended up costing a little too much.
Again, thanks for the ideas and input.