Jump to content

Our LonSupport team does not monitor this forum. Check our website for additional self help, and our free and paid support options.


We use the FT3150 P20 with a FT x1

  • Please log in to reply
1 reply to this topic

#1 jackfishbone



  • Members
  • Pip
  • 1 posts

Posted 12 March 2008 - 02:10 PM

We use the FT3150 P20 with a FT x1 jack fishbone jackfishbone jfishbone@phoenixcontrols.com

confused Greetings,

We use the FT3150 & FT x1 transformer.  The Processor provides a

2.5V Offset to the secondary of the transformer to enable the 0.6V  Bipolar Packets to be seen above and below gnd. The 2.5V circuit often gets blown out, and we would like to know what that circuit looks like ? 

Is it switched on or is it just developed from a resistor divider ?

We have no known ESD issues .  If we can find out what the circut looks like we might be able to determine how it is getting blown up.

Please email me at jfishbone@phoenixcontrols.com 

#2 ech-berke


    Advanced Member

  • Moderators
  • 2255 posts

Posted 13 March 2008 - 10:04 AM

We use the FT3150 P20 with a FT x1 Mike Berke ech-berke berke@echelon.com

It should definitely not be getting blown up.  I believe that the 2.5V bias is being generated by voltage dividers from 5V.  What voltage do the T1 and T2 pins go to when the FT 3150 is blown up?  What causes this failure?  You discount ESD, but ESD and Surge would be the only two things that would come to mind.  A short to 5V or GND would not damage the bias circuit for the T1/T2 pins -- it would take a significant transient.

Are you sure that the chips are not in reset when you are seeing T1/T2 not biased at 2.5V?  I believe that in reset they may float high, but I'm not 100% sure about that.

Mike Berke
Troubleshooting Guide -- "troubl2.pdf" at:

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users