In Nigeria, due to the epileptic nature of power supply, most institutions, individuals, and industries resort to self-generation of power via petrol and diesel generators, which does not only cause environmental and sound pollution but very expensive. As a result, the prices of domestic goods are on the rise. The threat of noise pollution and greenhouse gas emission associated with these generators cannot be over-emphasized. A renewable energy resource will provide a better alternative. This paper therefore designs and implements a regulated DC variable power supply of rating (0-15)V, 5A using solar PV with storage. The gap found from the literature review was; lack of digitally displayed output of the system. The paper designed and implemented DC variable power supply using a voltage regulator (LM33S), resistors, LED, capacitors, a solar PV of200 W, a 12V/24V20 A charge controller and two 12 V, l8Ah batteries. During the design stage, the voltage regulator capacity, solar PV, charge controller, battery ratings were designed. Tests were carried out with the aid of a digital multimeter to determine the response of the system. Results obtained showed that the system is capable of powering DC loads not greater than 75 W. It was also established that implemented system output voltage ranges from 1.21 V to 15.2 V. It was evident that basic experiments and other needs of DC power that are within the design range can be met.

There are many important balancing systems in control theory. The Ball-on-Sphere (BOS) system is one of these systems. It finds applications in aerospace, transportation, robotics, etc. The system is a nonlinear multiple-input multiple-output (MIMO) system where the ball is controlled on the sphere. It is a testing ground, due to its naturally nonlinear, under-actuation, and unstable nature, in nonlinear systems control. Consequently, different techniques have been used to control the system. A review of these techniques of comprehensive nature is presented in this paper. Different reputable publishers were considered using different search engines utilizing different search terms. The techniques include Linear Quadratic Gaussian (LQG), Sliding Mode Control (SMC), Fuzzy Logic Control (FLC), Artificial Neural Network (ANN), Feedback Linearization (FL), Linear Quadratic Regulator (LQR) and their hybrids. It was established that the system is not covered much in the literature. The LQR, LQG, and SMC were found to be the most used controllers to control the system. Also, 93% of the techniques used no optimization. Additionally, it was established that more techniques need to be explored for the system control. Control techniques hybridization and exploration and optimization usage were found to be the major future directions.