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For reasons hitherto explained, when the pump suddenly runs dry, the motor may not in fact actually speed up, it may just spin irregularly at some random speed, however fast or slow that speed may be.
Our buckboost feedback loop will only decrease current to the motor if it senses the motor speeding up above the nominal value (8000 rpm)
--yes we are trying to make it so that we can use it in our tulip field irrigation system...we don't have it built yet
...Right, but would the current to the motor just go and decrease when the pump suddenly runs dry?...please remember we are regulating the current to the motor with our buckboost...so our feedback loop is actually responsible for the level of current sent to the motor...if our feedback loop fails to detect motor overspeed when the pump suddenly runs dry, then our buckboost will not reduce the current that it sends to the motor.The Hall sensor would not be used for messing with the PWM (which is for applying a current limit); it would be solely for detecting the pump load change, independent of any 4425 or converter function.
For reasons hitherto explained, when the pump suddenly runs dry, the motor may not in fact actually speed up, it may just spin irregularly at some random speed, however fast or slow that speed may be.
Our buckboost feedback loop will only decrease current to the motor if it senses the motor speeding up above the nominal value (8000 rpm)
--yes we are trying to make it so that we can use it in our tulip field irrigation system...we don't have it built yet
yes it is capable of PWM'ing the IGBTs of the inverter, but we have bypassed that by grounding the ISENSE pin of the ML4425....for us, the ML4425 simply commutates from one coil to the next....we have VREF tied to SPEEDSET, so ML4425 just switches the IGBTs at 400Hz.But surely that's exactly what the 4425 does?
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