#Industry News
Application of power amplifier based on wireless control system
Stage lighting generally consists of a color changing system, a pattern changing system, and a spot cutting system. The technology of color changing system and pattern changing system has been relatively mature; the spot cutting system has attracted
Stage lighting generally consists of a color changing system, a pattern changing system, and a spot cutting system. The technology of color changing system and pattern changing system has been relatively mature; the spot cutting system has attracted more and more attention because of its ability to realize colorful pattern changes.
The light spot cutting system is generally provided by the external switching power supply of the system to provide electrical energy signals; the external main control board of the system controls pattern changes; the energy transmission and signal transmission media are electrical wires and wireless, respectively. When the light spot cutting system uses electrical wires to connect, the wire winding limits the rotation angle of the system, so that the continuous infinite rotation function cannot be realized, which greatly weakens the performance ability of the system. At the same time, a large number of connected wires and connectors may cause faults such as leakage and line heating.
The principle block diagram of the stage lighting spot cutting system based on wireless control is shown in the figure. It consists of 5 parts: electric energy transmission, power amplifier, electric energy reception, signal emission, signal reception and light spot control.
The controller converts the direct current into alternating current through the inverter drive circuit at the electric energy transmitting end, and loads it into the resonant transmitting circuit. The electric energy receiving end receives electric energy through the resonance receiving circuit, and provides energy for the motor of the modeling device after rectification, filtering and voltage stabilization. At the same time, the communication circuit and antenna realize two-way communication of data.
The wireless communication in the stage lighting spot cutting system based on wireless control requires a stable high-frequency transmission signal, which determines the reliable operation of the entire system.
In order to verify the reliability of the stage lighting spot cutting system based on wireless control, comparative experiments were carried out for the design of coils for power transmission with and without ferrite shielding materials, and the experimental data were compared with the calculation formulas and simulation results. verification. At the same time, a multi-machine operation monitoring experiment was done for the reliability of wireless communication.
The number of turns of the power coil that can be verified by the design is 6 turns, which can be divided into two cases: ferrite magnetic shielding material and non-ferrite magnetic shielding material. Considering that the resonance frequency is low and the skin effect is not obvious, the coil impedance is approximately equal to the DC resistance. The resistance measured by a multimeter is 0.659; the self-inductance of the unshielded coil and the coil with shielded material are measured respectively by using a bridge to be 7.05 uH and 13.0 uH.
Using 150 kHz, ±3V sine wave signal, the voltage amplitude is adjusted to ±30V through the power amplifier ATA-4012. The clamp device is used to keep the distance between the transmitter coil and the receiver coil at 3 mm, and the oscilloscope is used to measure the primary coil current l when the secondary coil is short-circuited and the output voltage Vout when the secondary coil is open, and calculate the mutual inductance M=Vout Iin. Finally, use a DC power supply and a power amplifier drive circuit to drive the power transmitting coil, and connect a resistive load at the output end of the power receiving coil, measure the input power and output power, and calculate the wireless power transmission efficiency.
The key issue of the stage lighting spot cutting system is energy supply. High-efficiency energy transmission needs to optimize the transmitting coil and receiving coil and related technical parameters. Through theoretical analysis, simulation and experiments, the design of the ferrite shielding structure flat spiral coil solves the problem of transmission efficiency and avoids the influence of changes in the surrounding environment on the magnetic circuit. In the future, with the increase of the spot radius, the space of the power coil is required to be smaller, and it is necessary to study the electric power coil with higher power density and efficiency.
