Use conductive pads; A coiled coil spring; Curled spiral shielding tape; High performance shielding tape; Silicone rubber core shielding washer; A plurality of sealing strips; Finger-shaped elastic pad; Metal woven mesh washer; Conductive rubber lining, etc.
2. Window shading method
A, cut off the waveguide or ventilation board;
B. Shielding window coated with film or metal mesh: used for monitors, etc.
3. Handling of operating equipment (such as knobs and keys of toggle switches).
A, when the signal frequency is high, the cutoff waveguide principle can be adopted;
B, when the signal frequency is low, you can use the isolation chamber to separate it from other circuit parts.
4. Operation of indicator dial
A, steel wire mesh shielding
B, cut-off waveguide method
C. Using filters
D, adding an isolation window
5. Conductor passing through the shielding layer
A. the shielded cable and the chassis form a fully sealed body;
B, filtering. Grounding is a wiring device for discharging or providing reference potential. Grounding has two purposes. First, protect personal and equipment safety and prevent lightning, leakage and static electricity. This kind of ground wire is called protective ground wire, which should be connected with the real earth. Second, in order to ensure the normal operation of the equipment, it is called working grounding wire.
1, suspend grounding.
A. The equipment ground wire is electrically insulated from the reference ground and other conductors, that is, the equipment floats;
B, in order to prevent the interference current on the chassis from being directly coupled to the signal circuit, it is intentionally insulated from the chassis, that is, the floating ground of the unit circuit.
2. Single point grounding
Single point grounding provides a common reference point for many connected circuits. Parallel single-point grounding is the simplest. It has no problems of impedance coupling and low-frequency grounding loop, so there is no disturbance.
3, multipoint grounding
Multipoint grounding can avoid the problem of single point grounding at high frequency. Digital circuits and high frequency and large signal circuits must be grounded at multiple points. Modules and circuits are connected by many short wires (
4. Hybrid grounding
Hybrid grounding includes both the characteristics of single point grounding and multi-point grounding. For example, the power supply in the system needs single point grounding, while the RF part needs multi-point grounding. Hybrid grounding uses reactance devices to make the grounding system show different characteristics at low frequency and high frequency, which is necessary in broadband sensitive circuits.
To sum up, the grounding of shielding machine room should consider mixed grounding.