Many industrial installations in developing countries start-up as small factories, without regard for the need of compensation of reactive power, leading to significant financial losses in the long term. By improving ...Many industrial installations in developing countries start-up as small factories, without regard for the need of compensation of reactive power, leading to significant financial losses in the long term. By improving the power factor, the customer can reduce its power demand and potentially increase efficiency of their equipment. A PIC microcontroller is used to switch capacitor banks to compensate for the reactive power. In order to determine the size of the capacitor bank needed, the microcontroller calculates the phase difference between the voltage and the current. The results obtained based on the lagging power factor for three test loads show an improvement in the power factor from 0.52 to 0.96 under different test load conditions.展开更多
Gastric disorders play an important role in digestive system of a human subject. Gastric disorder is due to the gastric dysmotility due to delayed gastric emptying and other motor dysfunctions like impaired fundic dis...Gastric disorders play an important role in digestive system of a human subject. Gastric disorder is due to the gastric dysmotility due to delayed gastric emptying and other motor dysfunctions like impaired fundic distention. Nowadays invasive technique like laparoscopy procedure, endoscopy procedure and surgery procedure plays a vital role in investigation of gastric disorders. Electrogastrogram is a noninvasive technique for analyzing digestive system disorders. In this proposed work, stimulation is delivered with the electrode package with camera, which travels through an esophagus to reach stomach and stimulate the interstitial cajal cells. Due to this stimulation the stomach starts, its activity a potential is provided that is recorded with electrode setup, which is called electrogastrogram. It is verified with its normal range 3 cpm. The stimulation includes pulses mode and continuous mode. Stomach function is recovered and its frequency is measured and the same is compared with normal range value. Depending upon the subject condition, the gastric activity is improved by setting different values of duty cycle. By this procedure the subject avoid painful procedure, stay in hospital, frequently and the cost is minimum.展开更多
This paper presents an electronic VSD （variable speed drive） for three-phase IM （induction motor） using a microcontroller. The VSD is designed for cooling applications where the 1M is coupled to a cooling fan. The...This paper presents an electronic VSD （variable speed drive） for three-phase IM （induction motor） using a microcontroller. The VSD is designed for cooling applications where the 1M is coupled to a cooling fan. The drive receives temperature feedback from objects to be cooled and output a corresponding frequency to the IM. A prototype of the VSD is constructed to control a 175 W, four pole, squirrel cage three-phase IM. The heart of the control circuit is a low-cost microchip＇s PICI6F777 microcontroller which is programmed using C language to generate variable frequency SPWM （sinusoidal pulse width modulation） switching signals. These switching signals are fed to an 1GBT inverter. The VSD constructed can be switched between two modes of speed control＂ automatic temperature-controlled mode and manual user-controlled mode. Cost savings using the prototype are demonstrated.展开更多
文摘Many industrial installations in developing countries start-up as small factories, without regard for the need of compensation of reactive power, leading to significant financial losses in the long term. By improving the power factor, the customer can reduce its power demand and potentially increase efficiency of their equipment. A PIC microcontroller is used to switch capacitor banks to compensate for the reactive power. In order to determine the size of the capacitor bank needed, the microcontroller calculates the phase difference between the voltage and the current. The results obtained based on the lagging power factor for three test loads show an improvement in the power factor from 0.52 to 0.96 under different test load conditions.
文摘Gastric disorders play an important role in digestive system of a human subject. Gastric disorder is due to the gastric dysmotility due to delayed gastric emptying and other motor dysfunctions like impaired fundic distention. Nowadays invasive technique like laparoscopy procedure, endoscopy procedure and surgery procedure plays a vital role in investigation of gastric disorders. Electrogastrogram is a noninvasive technique for analyzing digestive system disorders. In this proposed work, stimulation is delivered with the electrode package with camera, which travels through an esophagus to reach stomach and stimulate the interstitial cajal cells. Due to this stimulation the stomach starts, its activity a potential is provided that is recorded with electrode setup, which is called electrogastrogram. It is verified with its normal range 3 cpm. The stimulation includes pulses mode and continuous mode. Stomach function is recovered and its frequency is measured and the same is compared with normal range value. Depending upon the subject condition, the gastric activity is improved by setting different values of duty cycle. By this procedure the subject avoid painful procedure, stay in hospital, frequently and the cost is minimum.
文摘This paper presents an electronic VSD （variable speed drive） for three-phase IM （induction motor） using a microcontroller. The VSD is designed for cooling applications where the 1M is coupled to a cooling fan. The drive receives temperature feedback from objects to be cooled and output a corresponding frequency to the IM. A prototype of the VSD is constructed to control a 175 W, four pole, squirrel cage three-phase IM. The heart of the control circuit is a low-cost microchip＇s PICI6F777 microcontroller which is programmed using C language to generate variable frequency SPWM （sinusoidal pulse width modulation） switching signals. These switching signals are fed to an 1GBT inverter. The VSD constructed can be switched between two modes of speed control＂ automatic temperature-controlled mode and manual user-controlled mode. Cost savings using the prototype are demonstrated.
