Electro-dynamic. Transformation of the impedance, speakers, resonators. Tele-screen. Thermo-emission, video-amplifiers, deflection, luminophore. Transformer. Fading current, classes of security, inner resistance. Power sources. Doublers, multiplier, pulse rectifier, electro-magnetic compatibility. Disturbance distance. Grounding, noises, el. and mag. fields, humidity, photo-sensitivity, microphony. Disturbance distance, grounding of wide systems, uniphase processes. Metals, alloy, polymers. Strength, thermo-stability, cutting, jointing. Metal plating. Conductivity of solution, corrosive protection. Printed circuits. Cuprextit, photo-resistor, current rating, printed inductor. soldering.