May 04, 2019, 11:14 AM
Bruce WilliamsMSD Crank trigger
Is the pickup used on the flying magnet crank trigger an inductive or hall effect sensor?
I presume the pickup in the MSD distributors would be the same?
May 04, 2019, 10:29 PM
imakehpThe MSD Flying magnet crank trigger uses a non-magnetic Hall Effect sensor...
May 05, 2019, 06:59 AM
Alaskaracerquote:
Originally posted by imakehp:
The MSD Flying magnet crank trigger uses a non-magnetic Hall Effect sensor...
It does not. It uses an inductive, non-magnetic sensor. When a magnet passes by the sensor, it induces a small voltage which is "seen" by the ignition, resulting in a triggered event. On a hall effect, it sends a reference voltage to the sensor, and is toggled between 12v and ground. A hall effect sensor generally requires three wires to work, +12v, ground, and signal return. The inductive does not have the +12v wire, only the ground and signal return......FAST uses a hall effect sensor on their crank trigger, MSD uses an inductive. The FAST version uses a magnetic pickup and a tone ring that they call the trigger wheel. It has metal points that trigger the ignition rather than magnets.....The Most cars these days also use a hall effect since they are less prone to interference than an inductive and provide a more stable signal.
May 05, 2019, 02:57 PM
imakehpBruce, I’ve always thought a Hall effect sensor was non-magnet pickup. I would disregard my advice and give MSD a call Monday for correct info. Not saying the above isn’t spot on, just saying MSD would be a 100% for sure....
May 05, 2019, 03:29 PM
Bruce WilliamsThank you for all of your replies.
May 05, 2019, 03:53 PM
Buckyquote:
Originally posted by imakehp:
Bruce, I’ve always thought a Hall effect sensor was non-magnet pickup. I would disregard my advice and give MSD a call Monday for correct info. Not saying the above isn’t spot on, just saying MSD would be a 100% for sure....
My flying magnet was a two wire magnetic or inductive pickup. When I switched to the toothed wheel I also switched to a hall effect three wire.
May 05, 2019, 10:24 PM
Mike BeckA stock MSD Flying Magnet setup comes with a two wire inductive pickup.
Holley makes a Hall Effect pickup that will go right in it's place, three wires, one needs switched +12v, another goes to ground, the other is the signal output, or return, whatever term you want to use. THAT wire can go to the Points Input on an MSD (or similar) box to trigger it.
Hall Effect sensors are superior due to their electrical noise rejection, but they do cost more. They also are not finicky with sensor gap. An inductive pickup produces very little voltage output at low rpm, especially cranking. They produce a LOT of voltage at high rpm, and can cause issues if the gap is too small. It basically overdrives the input to the MSD box with too much voltage.
There are two different types of Hall Effect sensors. One responds to a magnet passing-by. The other has a built-in magnet and responds to a ferrous metal (typically steel) passing-by that "completes" the magnetic field inside the sensor. I think this is what a lot of OEM's use, like an LS engine, that has a toothed metal ring pressed onto the crank inside the engine. I never took one apart myself yet. They are also widely used in industrial machines. The other type that requires a magnet passing-by is used in ABS systems with the toothed rings on axle shafts and rotors, you always see metal stuck to them when doing brake jobs.