An efficient Light Emitting Diode (LED) lamp driver circuit is proposed for retrofitting the conventionally used incandescent lamps with existing TRIAC dimmer. The dimming feature in a wide range of firing angle from 30¢X to 130¢X can be accomplished by means of double pulse-width modulation (DPWM) and analog current regulation. The LED lamp driver adopts a flyback converter with an auxiliary active power MOSFET for synchronous switch and an associated inductor for zero voltage switching (ZVS), leading to lower switching loss and thus achieving a higher circuit efficiency. In the thesis, the mode operation of the driver circuit is analyzed and the design equations are derived accordingly. A laboratory circuit is designed for an 50 W LED lamp which is composed of 45 high-brightness white LEDs in series. Experiments are carried out to test the circuit performances with two dimming schemes. The experimental results indicate that the driver can achieve a circuit efficiency of 95 % at the rated output. When the LED lamp is dimmed, the circuit efficiency with DPWM is higher than that with the analog current regulation. On the other hand, the LED lamp dimmed by analog current regulation has a higher efficiency but a less color shift by DPWM.

This work deals with designing complete equipment of paludarium. Selection of individual components to simulate jungle conditions and automate the process of maintaining the forest conditions in a closed environment. All components of the project will be automatically controlled to maintain a user-set conditions inside paludariums. The measured data will be stored on the SD card.

The aim of my master’s thesis is a system for control of the light intensity. It is electronic equipment which controls the intensity of the light circuits based on settings and input signals. This equipment could work on single-phase systems or multiphase systems. The equipment is controlled by the signal DMX-512 which is a standard for the control of lighting technologies. The set up of this equipment is based on a personal computer or in a limited form by a small connected display.

This thesis deals with design and implementation of a versatile control unit, which is primarily designed for control of solar collectors. It describes the various stages of design. First, the system of solar collectors is introduced. Its input-output parts are analyzed and the requirements are determined for the control unit. The characteristics of temperature sensors are examined, the work deals with continuous variable speed circulators. The following part is dedicated to hardware and software implementation of the objectives of the work. The boards were designed in Eagle design environment, the firmware was written in C programming language. In conclusion, the evaluation of the results of the proposed system and possible ways of its further development are discussed. The versatile control unit can be deployed in practice realistically.