CONTROLLED LED SYSTEM FOR LIGHTING PLANTS IN GREENHOUSE

摘要

A controlled lighting system contains LED lamps, power supply, voltage converter, resonant transformer, power line and control unit connected to several voltage converters, separate for each color, wherein a voltage converter is connected to n transmission lines (n = 1, 2, 3. .. k), which are connected in parallel through restrictive capacitance or inductance to m luminaire circuits (m = 1, 2, 3, ... p). In each circuit one to several lamps consisting of z light-emitting diodes (z = 1, 2, 3 ... x) are connected in series, the control unit outputs are connected to corresponding voltage converters, and individual colored LED lamps can be combined into one. The voltage converter is an electronic generator of sinusoidal oscillations, made on two transistor amplifiers with positive feedback through a Wien bridge employing RC-elements; through the series-connected first and second transistor amplifiers the Wien bridge output is connected to the primary winding of the resonance transformer, the second amplifier collector output is connected to a Wien bridge capacitor, the emitter of the first amplifier transistor is linked through a resistor voltage divider connected to the output of the second amplifier, control input of the electronic sine wave oscillator formed by a circuit of two series-connected LEDs for irradiating Wien bridge photoconductive cells is connected to the output of the control unit, while blank terminals of LED circuit, Wien bridge and amplifiers share a common bus.