Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/11/1997
Publication Date: N/A
Interpretive Summary: The automatic feed control system on a roller gin stand monitors and adjusts the seed cotton feed to a pre-selected feed rate. The control system compensates for differences in the seed cotton such as trash and moisture content. The present design of the control system uses a power- type electrical transducer to measure the load on the rotary-knife motor. An experiment was run to determine if either a power factor transducer or current transducer could instead be used to measure the motor load. Using either one of these transducers simplifies the design of the control system. Results showed that the power transducer and the power factor transducer worked successfully in this application. However, due to the fact that the rotary-knife motor operates mostly at low load, the current transducer did not perform well. Those roller ginning plants who plan on incorporating the automatic feed control system on their gin stands should use either a power transducer or power factor transducer, and not a curren transducer, in their design.
Technical Abstract: Three types of electrical transducers were tested for use on a roller gin stand automatic feed control system. The automatic control system monitors and adjusts the seed cotton feed rate to a pre-selected level while automatically compensating for differences in the seed cotton such as trash and moisture content. An electrical transducer, which is part of the design of the automatic control system, measures the input signal from a motor driving a rotary knife, and then proportionately converts and sends this signal as direct current to a digital controller. The controller then outputs the DC signal to a motor control which operates the feed rollers on the feeder. Transducer types tested included a power transducer which measured the input signal in watts, a power factor transducer which measured the phase angle between the voltage and current waves, and a current transducer which measured the signal in AC amperes. Results showed dthat all three transducers converted the input signal from the rotary-knif motor to an output DC signal. However, because the rotary-knife motor operated mostly at a low load, the power and power factor transducers converted the signal more effectively.