Transistor output leakage

[xJAyx]

I have an application where a transistor output on a GE PLC is used to trigger a solid state interposing relay. The could voltage on my relay is 120VAC, and the PLC card is rated for 120 as well. It seems as though the leakage through the transistor is enough to energize my interposing relay. I can see the LED on my relay drop in intensity, but it remains slightly lit, and my contacts remain energized.

Are these two devices just not compatible, or is there a proper way to overcome this issue, such as using a certain device similar to a snubber etc.?

 

[IRstuff]

Switching AC with solid state devices is often tricky. There may be many parasitic devices that don't know they're supposed to be off. One option is to use a standard relay to switch the voltage for the other relay. I've got some automated light switches with mechanical switches to eliminate the residual leakthrough. But, I've got other solid state switches driving LED Christmas lights that have sufficient leakthrough to keep them partially lit.

TTFN
faq731-376

 

[itsmoked]

Try adding 56k ohm 1/2W resistor across the SSR input.

That will shunt 2mA around the SSR. It might be enough.

Keith Cress
kcress -

http://www.flaminsystems.com