Today is...
Friday, December 14, 2018
Welcome to, the global online
community of automation professionals.
Featured Video...
Featured Video
Watch an animation of a conveyor stacking operation demonstrating the use of a move on a gear command.
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?