Aigtek power amplifier application in wireless controlled stage lighting spot cutting system

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Aigtek power amplifier application in wireless controlled stage lighting spot cutting system [Copy link]

Stage lighting is generally composed of color-changing system, pattern-changing system and spot-cutting system. The color-changing system and pattern-changing system technologies are relatively mature; the spot-cutting system is gaining more and more attention because it can achieve colorful pattern changes.

The spot cutting system is generally provided with power signals by the external switching power supply of the system; the pattern changes are controlled by the external main control board of the system; the energy transmission and signal transmission media are electric wires and wireless respectively. When the spot cutting system is connected with electric wires, the rotation angle of the system is limited due to the entanglement of the wires, so that the continuous infinite rotation function cannot be realized, which greatly weakens the performance of the system. At the same time, a large number of connecting wires and connectors may cause leakage, circuit heating and other faults.

The principle block diagram of the stage light spot cutting system based on wireless control is shown in the figure, which consists of five parts: power transmission, power reception, signal transmission, signal reception and light spot control.

The power transmitter converts direct current into alternating current through the inverter drive circuit and loads it into the resonant transmitting circuit. The power receiver receives power through the resonant receiving circuit and provides energy for the modeling device motor after rectification, filtering and voltage stabilization. At the same time, the communication circuit and antenna realize two-way communication of data.

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 light spot cutting system based on wireless control, comparative experiments were conducted on the coils designed for power transmission with and without ferrite shielding materials, and the experimental data were compared with the calculation formula and simulation results. At the same time, a multi-machine operation monitoring experiment was conducted on the reliability of wireless communication.

The number of turns of the power coil that can be verified is 6, which is divided into two cases: with ferrite magnetic shielding material and without ferrite magnetic shielding material. Considering the low resonant frequency and the insignificant skin effect, the coil impedance is approximately equal to the DC resistance. The resistance measured by the multimeter is 0.659; the self-inductance of the coil with and without shielding material is measured by the bridge, which is 7.05 uH and 13.0 uH respectively.

A 150 kHz, ±3V sine wave signal is used, and the voltage amplitude is adjusted to ±30V through the power amplifier ATA-4012. A fixture device is used to keep the distance between the transmitting coil and the receiving coil at 3 mm. An 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 the mutual inductance coefficient M=Vout Iin is calculated. Finally, a DC power supply and a power amplifier drive circuit are used to drive the power transmitting coil, and a resistive load is connected to the output end of the power receiving coil, and the input power and output power are measured to calculate the wireless power transmission efficiency.

The key issue of the stage lighting spot cutting system is energy supply. High-efficiency energy transmission requires optimization of the transmitting coil and receiving coil as well as related technical parameters. Through theoretical analysis, simulation and experiments, a flat spiral coil with a ferrite shielding structure is designed to solve the transmission efficiency problem and avoid the influence of changes in the surrounding environment on the magnetic circuit. In the future, as the spot radius increases, the power coil space will be required to be smaller, and it is necessary to study power coils with higher power density and efficiency.