Today is...
Thursday, May 24, 2018
Welcome to, the global online
community of automation professionals.
Featured Video...
Featured Video
EtherCAT with CTC’s master lets your multivendor network play well together...
Our Advertisers
Help keep our servers running...
Patronize our advertisers!
Visit our Post Archive
Matrix SSR/triac Switching
Leakage in SSR matrix. How to fix?
By queenidog on 6 April, 2018 - 1:47 pm

I have a large number of 110VAC lights that are controlled by an SSR matrix. I have 3 large SSRs that control 3 power buses (RGB) and a number of other SSRs that control the lights I want to turn on. First I have to turn on the power bus (one of the three colors RGB or any combo of the 3). Then I turn on an SSR for the particular light. So if I want a green light to go on, I turn on the Green SSR, then apply a signal to the light SSR (which has 3 bulbs, RGB attached to it). I am getting lots of leakage such that my 3 separate buses act like they are all shorted together. With just ONE SSR active, all three buses have voltage on them and so I end up with 3 lights going on simultaneously instead of the ONE light I wanted. When I modeled this with LEDs (no SSRs) it worked fine, of course. To be clear, I have a matrix with 3 columns and 16 rows. The three columns energize via 3 unique SSRs, the 16 light SSRs are on two PC boards. Each SSR is basically an input of a logical AND gate: both required in order to get an output.

I've read on this site about snubbers and could see this as a problem. But I have lots and lots of relays to snub with a 10K resistor or equivalent, and being high power, very inconvenient. Any other solutions?