H. E. Orovwode

Construction and Operation of an Electronic Automatic TransferSwitch (Ats)

The inconsistency of power supply in Nigeria has been a major stumbling block to the advancement of her economy and as such it is an issue that requires immediate attention. Uninterrupted power supply is critical in so many applications especially in cases like hospital operations or financial transactions. This work was born out of the need to provide a cost effective and locally available way to automate the switching between various power sources. This issue can be addressed by implementing an Automatic transfer switch which automatically switches on a backup generator in the absence of the utility supply and transfers the load to the generator. The automatic transfer switch also switches off the backup generator and connects back to the utility supply when the power comes back. The circuitry consists of time delay integrated circuits and switching relays. The present effort is a prototype design to create an automatic transfer switch that can be used in an average Nigerian household because of its affordability and simplicity of operation.

Analysis of a Weaver, Hartley and Saw-Filter Based, Image Reject Architectures for Radio Receiver Design

This paper presents an analysis of the three popular image reject architectures used in radio receiver design. The SAW-filter based image reject architecture is the simplest to implement and has the lowest power consumption while the weaver is the most complex with the highest power consumption. The Hartley architecture which utilizes half the number of mixers used in the weaver architecture does not consume as much as the weaver architecture but is not as efficient due to the use of the 900 phase shifter. The three architectures are optimized for various design specifications. The receiver design with power constraints is better realized using the SAW filter while the receiver with portability as its highest priority is better realized using the weaver architecture. The architecture implemented for any particular radio design is determined by the receiver specification with the highest priority.

Management of Existing Capacity of Electric Power with Energy Saving Devices

The strategy of management of the existing capacity by proper illumination design and the use of energy saving devices in the residential sector is reported. Improper installation design and the use of all sorts of devices at homes has led to a lot of electrical energy wastages resulting in the need to increase the generation capacity. The study revealed that annual energy of 551.88kWh could be saved for a three – bedroom flat when energy saving fluorescent lamps were used. The corresponding naira savings was 2,207.52 per annum. In addition, the sizes of cable, fuses/circuit breakers required are reduced and hence reduction in the cost of installation. The paper advocates the need for proper design and installation of energy saving devices in homes. The paper will be of relevance to lighting installation designers, power systems engineers, power utility managers, and the general public.