1. Hardware
  2. Questions
0

Are Diodes or TVS required when using a COUT for On/Off control (NOT Proportional)

Mark Bevington 2 weeks ago • updated by Tim Reen 2 weeks ago • 1

Hi,

We are converting a machine that had MC2's, XA2's, XS2's & MC3's to use MC43's or XC43's. There were not enough DOUT's when the application was originally written, so COUT's were used and driven from either 0% to 100%, or from 100% to 0%.  There is no proportional control used.  The command input to the COUT is either 0% or 100% can instantaneously switch  from either OFF to ON, or ON to OFF at a 10 mS system cycle time. See below for an example of the code. Are TVS, or Diodes, required across the COUT to protect the outputs from instantaneous changes??   

Image 5210

Tim Reen 2 weeks ago

Transient voltage suppression is not required on COUT channels. Often we see on/off valves where proportional valves may be implemented in the future, so we use COUT channels for on/off applications occasionally - and they work fine. The only consideration would be setting the maximum current for the on/off load to prevent saturation.

Customer support service by UserEcho