Analysis: What Are The Anti-interference Measures For Static Voltage Stabilizers?

All the switch input and output ports of Static Voltage Stabilizer are isolated by photocouplers. In addition to using photocouplers to isolate the trigger pulse output circuit of the thyristor, transformer isolation is also used to prevent reverse interference from the higher voltage of the main circuit. A 01 circuit is also used in the circuit to improve its anti-interference ability. In order to ensure the normal operation of the microcomputer floating ground, the ground wire of the analog input port should also be isolated from the microcomputer ground wire. Although the use of equal isolation amplifiers can achieve isolation of internal and external ground wires, the anti-interference ability is limited because such amplifier modules use transformer coupling technology. In the experiment, it was found that narrow spike pulse interference can penetrate into the sampling and conversion circuit of the microcomputer, causing control errors. For this reason, after the analog quantity is converted into digital quantity and before entering the microcomputer, each digital quantity is isolated by a photocoupler.

Because the photocoupler is a current-type device, it has a good suppression effect on narrow spike pulse interference signals, and can obtain better anti-interference ability and higher conversion accuracy. Power supply anti-interference: The power supply of the microcomputer adopts a static voltage stabilizer, a super isolation transformer, a two-line low-pass filter, and an anti-interference type microcomputer switching power supply. Tests show that this system has good anti-interference performance, which can ensure that the microcomputer is not interfered by the AC power supply. The power supply of the peripheral circuit is drawn from the static voltage stabilizer and realized through another super isolation transformer to prevent mutual interference between the peripheral circuit and the microcomputer. Other anti-interference measures include: signal input filter network, digital filter program, trap program, use of integrated circuits, separate wiring of power lines and control lines, and use of shielded lines for microcomputer signal lines.