Turbocharger speed signal issue
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Dear experts, is the turbine speed signal that comes in from the field a frequency signal? If it has 30 teeth, what is the range of this frequency signal?
The rotation speed is generally measured using a magnetoresistive probe (MPU). A tachogear is installed on the turbine shaft; each time the probe passes over one tooth of this gear, it cuts through the magnetic field lines, causing the voltage to rise and fall. By setting a voltage threshold, it is possible to determine how many teeth the probe has passed. As indicated in the title, the speed measurement gear has 30 teeth; every time 30 teeth pass by, thirty pulses are generated, which corresponds to one full rotation. RPM = (60*f)/PPR. RPM represents the rotational speed in revolutions per minute; f is the frequency in Hz, or cycles per second; PPR refers to the number of pulses per revolution, or the number of gear teeth. Therefore, when measuring rotational speed, there is no frequency range specified – instead, a range for rotational speed is used, with the conversion being carried out through formulas within the control system
Find the maximum speed of the turbine unit; it varies depending on the type of unit. Unit speed = (frequency/30)*60 rpm.
Is there such a conversion formula? Last year I encountered a fault where the shutdown of the system was caused by damaged shielding on a speed probe