Quote:
Originally Posted by icingdeath88
The VR conditioner that's used in yours I think is different than the one that's in the MS3. Do you know if there are a couple of adjustable "pots" on the board? So it may not be directly applicable, but I, and probably Mike if he searched the MS forums, was able to find the old posts by you and the guy who helped set it up initially, that cover what was done: http://www.msextra.com/forums/viewto...p?f=94&t=24695
Matt, do you know where along the wire the resistor was added?
Also, a question. On the MS forums one of the fixes for sync loss is adding resistors, but sometimes they are added inline with the signal wire, and sometimes, they are added across the signal and ground wires. Or sometimes both. What does this accomplish and why would that be a remedy? Harvey? Or anyone? |
The signal from these type of sensors is a low level AC sine wave. The voltage rises to peak then falls to zero, to cross to the opposite voltage. It is the zero crossing that they use to trigger the controller.
If the signal is reduced by a mismatch of the impedance, the voltage will be lower, and the zero crossing point will not be as sharp, and harder to detect.
The problems stem back to the Inductive pick-up that the engine has. These are an electrical generator, that produces a voltage wave form that depends on the circuit load, and the rate of change, rpm.
This allows the signal to be too much voltage, from the speed or a higher than normal impedance, or too low a voltage from too low a impedance. Also because they generate a such a low voltage, it is prone to interference from all the other electrical equipment. To be reliable they need the input circuitry to be matched to the inductor.
If the impedance is too low, fitting a resistor in series with the signal will prevent the voltage from being reduced. If the impedance or the voltage is too high, fitting resistor across the signal or the pot as a voltage divider, will reduce the level,
It would be better to replace the inductive unit with a Hall Effect unit. These produce a 5v square wave that is immune to interference, and does not change with speed or load. A shutter could be fitted behind the crank pulley.
Harvey.