This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency o...This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency of timer output waveform which is measured using a digital storage oscillator(DSO)is almost linearly proportional to the applied input voltage.Hence we obtain a linear relationship between the frequency of timer output waveform and the input voltage.Because of its quasi-digital output,the main advantages of this developed converter are linear input-output relationship,small size,easy portabilityand high cost performance.In addition,the timer output waveform can be directly interfaced with personal computer or microprocessor/microcontroller for further processing of the input voltage signal without intervening any analog-to-digital converter(ADC).展开更多
Dust accumulation on photovoltaic (PV) panels degrades PV panels’ performance;leading to decreased power output and consequently high cost per generated kilowatt. Research addressing the severity of dust accumulation...Dust accumulation on photovoltaic (PV) panels degrades PV panels’ performance;leading to decreased power output and consequently high cost per generated kilowatt. Research addressing the severity of dust accumulation on PV panels has been ongoing since the 1940s, but proposed solutions have tended to increase the cost of PV systems either from oversizing or from cleaning the system. The objective of this work, therefore, is to design and implement a low-cost affordable automated PV panel dust cleaning system for use in rural communities of Sub-Saharan Africa (SSA);where financial resources are limited and significantly strained in meeting livelihood activities. Complete design and implementation details of a prototype system are provided for easy replication and capitalization on PV systems for sustainable energy needs. The system detects dust based on the innovative use of light-dependent resistors. Testing and observation of the system in operational mode reveal satisfactory performance;measured parameters quantify a power output increase of 33.76% as a result of cleaning dust off the PV panel used in the study.展开更多
文摘This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency of timer output waveform which is measured using a digital storage oscillator(DSO)is almost linearly proportional to the applied input voltage.Hence we obtain a linear relationship between the frequency of timer output waveform and the input voltage.Because of its quasi-digital output,the main advantages of this developed converter are linear input-output relationship,small size,easy portabilityand high cost performance.In addition,the timer output waveform can be directly interfaced with personal computer or microprocessor/microcontroller for further processing of the input voltage signal without intervening any analog-to-digital converter(ADC).
文摘Dust accumulation on photovoltaic (PV) panels degrades PV panels’ performance;leading to decreased power output and consequently high cost per generated kilowatt. Research addressing the severity of dust accumulation on PV panels has been ongoing since the 1940s, but proposed solutions have tended to increase the cost of PV systems either from oversizing or from cleaning the system. The objective of this work, therefore, is to design and implement a low-cost affordable automated PV panel dust cleaning system for use in rural communities of Sub-Saharan Africa (SSA);where financial resources are limited and significantly strained in meeting livelihood activities. Complete design and implementation details of a prototype system are provided for easy replication and capitalization on PV systems for sustainable energy needs. The system detects dust based on the innovative use of light-dependent resistors. Testing and observation of the system in operational mode reveal satisfactory performance;measured parameters quantify a power output increase of 33.76% as a result of cleaning dust off the PV panel used in the study.
