2-10
Pre-installation Guidelines
TI545/TI555 System Manual
Correcting Noise Problems (continued)
You can also use contact snubbing (shown in Figure 2-6) as an alternative
type of snubbing.
Both types of snubbing cause the physical devices to come on or go off more
slowly. The resistance-capacitance (RC) and metal oxide varistor (MOV)
elements should have minimal effect on system timing; their time constants
are substantially less than one millisecond.
Discrete
input
Load
C
R
Discrete input
module protection
RC snubbing
Discrete
input
Load
Discrete input
module protection
MOV snubbing
MOV
Input Power
Input Power
Figure 2-6
Contact Noise Snubbing
NOTE:
Noise snubbing shown in Figure 2-6 is built into the PPX:505-5518
Relay Output module.
