Linas Svilainis

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Sun and ambient light is a serious problem for outdoor LED video displays. Shading the front-face surface by louvers implementation is used in majority of LED displays, but louvers influence the LED directivity. The analytical method is developed for image visibility estimation. The louver geometry and position are taken into account. LED FFP goniometry is(More)
The ultrasonic transducer excitation circuits have been investigated. The system structure is presented where excitation circuit is planned to be used. The possible excitation solutions are presented and discussed. The result of impedance measurement of ultrasonic transducer has been used to derive the Butterworth-Van Dyke electrical model.Then this model(More)
LED PWM dimming application for large scale LED video displays is analyzed. The need for short light pulse duration is outlined. PWM dimming with short driving pulses is investigated experimentally. The LED response time skew introduces the nonlinearity for PWM dimming. For LED response time skew estimation, a method is suggested that has been successfully(More)
Practical aspects of design and application radio frequency (RF) transformers in an ultrasonic system excitation channel are analysed. Design steps are discussed for those willing to design their own transformer an for excitation channel. Investigation has been carried out on what generator parameters can be obtained if instead of a purely active output(More)
Paper is analyzing the ultrasonic preamplifiers performance comparison problem. Technique and equipment for ultrasonic preamplifier's performance evaluation and different manufacturers' products comparison has been established. Equipment used and measurement technologies applied are described and presented. Experimental results for the measured complex gain(More)
The concept of the measurement system dedicated for air coupled ultrasound navigation study is presented. The proposed system is portable as it is intended for field experiments. In particular, it is planned to use it research, rapid prototyping and signal processing experiments of vehicle parking-guidance systems, transport docking platforms orientation,(More)