MICRO-PROCESSOR BASED TEMPERATURE CONTROLLER ON POWER TRANSISTORS

Mulwa P.K, Muia L.M, Ogola W.O

Abstract: Radio frequency (RF) signal amplification was considered to solve the power transistor’s problems caused by temperature. The goal is to minimize power losses and maximize signal area of coverage. The problems are drift, gain loss and failures in power transistors. This is mainly caused by temperatures exceeding preset design limit. These problems lead to low radio frequency power output and white noise in output signal. Micro-Processor based temperature controller was designed to solve the problem. Experiment was carried out to determine the required air flow rate at a certain ambient temperature and power transistor temperature. Intercooled stata 8.0 software was used and gave characteristic depicting power loss and the regression coefficient (r2 ) for the independent and dependent variables. Through the research, design and testing an intelligent temperature controller monitoring both ambient air and power transistors temperature hence realizing the required ambient air flow rate was achieved. This enhanced RF power transistors to increase the power of carrier signals, increase the range of radio waves and suppress noise in the wanted signals.

Keywords: Power loss, Temperature, Drift, Gain Loss, White Noise.

DOI: https://doi.org/10.15623/ijret.2014.0305146