Using a 5 vdc Power signal toggle to activate a Pin on SainSmart 16 relay.

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1

I have a couple of SainSmart relay boards that the driver is ACTIVE LOW. I am actually trying to have all the relays be active or not by supplying an active low signal via a switch and an external 5 vdc supply
(https://smile.amazon.com/gp/product/B00J3MHT1E/ref=ppx_yo_dt_b_asin_title_o09__o00_s00?ie=UTF8&psc=1). Basically I am wiring two different PLCs to the same Widgets.

I will be using only one PLC at a time. I want to use the same exact SSRs and Widgets for both PLCs, just not at the same time. I would run the Control from the SSR to the Relay Common. PLC #1 Digital Out Control Signal to the NO Pin, PLC #2 Digital Out Control Signal to the NC Pin.

So when the Toggle is made, PLC #1 would be the driver. When Off, PLC would be the Driver.

The Active Low on the SainSmart Board is not what I understand. Do I need a couple of resistors and a small transistor?

aCTIVE lOW SIGNAL.png
aCTIVE lOW SIGNAL.png1890×818 9.87 KB

2

Could be that the Sainsmart 16-relay board already has a 12volt>5volt buck converter buildin (most do).

All you might need is a switch from relay input to relay ground (no resistors).
Leo..