Slip ring transmission dozens of different signals, high-frequency alternating current, high voltage alternating current, high current AC, DC with small signal weak, because the distance between the slip ring close to a variety of signal during transmission interference with each other. Various disturbances seriously affect the accuracy of the information transmission. Signal transmission interference generated electrostatic inductive coupling, magnetic inductive coupling and electromagnetic induction coupling.
 

1, the electrostatic interference caused by inductive coupling
Such interference is due to the capacitance between the wires between the rings and the distributed capacitance caused by the voltage generated by electrostatic induction
The interference frequency and the size of the two capacitors.
. l / W C Dry L2 "1,
j-c ~ --- {, -] /-R-(-C-j-2-+-C-a ze)
Where: V - generated interference voltage;C 2 - ring capacitance, (F / in);C. - Disturbed conductor capacitance to ground, (F / m);- Interference source angular frequency;
R - interference between conductor and earth resistance value, (Q);
V - the voltage of the source of interference.
When R "when the south. vN an R. c_z · Vj
When R "side iI-time. vN a [JV L
When the interference source is a high voltage, low current, mainly electrical interference, can be used to reduce the interference field shielding. Specific interference conductor plus shield in the shield grounded at one end.

2, the magnetic field generated by inductive coupling interference
Because slip ring wires in close proximity, the rings also very close distance. When alternating current through, the mutual action of adjacent wires and rings produce mutual inductance voltage. Both interference voltage. This interference voltages available formula V = j (0-M · I calculated.
Where: V - generated interference voltage;
. - Interference source angular frequency;
M - Ring asked mutual inductance;
I --- interference source current.
When the interference source is a low voltage, high current, the magnetic disturbance magnetic shielding should be used. Magnetic shielding mainly inhibit the coupling of magnetic interference shielding low frequency magnetic field is often used high permeability ferromagnetic material. High frequency magnetic field shielding can be a good conductor of a low resistivity material, and both ends of the shield conductor to ground.

3, electromagnetic interference - Interference hybrid electric and magnetic fields
When the interference source voltage is high, the frequency is high, easy to use electromagnetic shielding, conductive material of the shield can be thrown, which can interfere with the electrical and magnetic interference shielding also play a role.
"No disturbance information transmission device" is the use of conductive shielding material of the slip ring. We will produce interference source signal
Number of rings to be shielded with shielding ring. Meanwhile, the small signal through fear of interference rings are shielded with shielding ring, slip ring output conductors shielded wire brush holder is also used to input wire shielded cable and shielded lines, respectively, all through the brush holder and the ground then, the wiring in the form shown in Figure 2. Practice has proved that the interference substantially to reduce the installation of shielded to reduce interference in the form, the structure is more complex, bulky, in the case of space should be allowed in the main source of interference shielding ring ring up and down the installation.

4, current and voltage disturbances caused by mutations
Input signal at the input line switch process, due to current and voltage mutations cause interference. To reduce such interference can switch near to install filters to minimize interference voltage into the slip ring leads.

5, the current and voltage fluctuations in the value of interference
When transmitting high current or high voltage, due to the current value of ± lO voltage fluctuations in the wire forming surge, resulting in interference. Interference can be caused by the sudden surge suppressors to reduce crossing.
Such measures can reduce the slip ring between the electromagnetic interference.