I'm going to reply/post on this post with a Use Case topic because @david4 has the picture right there and has made the most recent complete post on these devices (and you guys following this thread seem to care about the applications thereof).
So, here's my objective.
To control a 12VDC (less than 1amp under load) actuator which when wired and powered in one polarity will extend to the point of the internal fully extended limit switch. When wired and powered in the opposite polarity it will retract to the point of the internal fully retracted limit switch. These are typically set up with DTDP relays or just a momentary rocker switch that powers -/+ in one throw and +/- in the other.
I have one of these devices ( the 4 relay version) in a location where I am using two of the relays and I am wondering if I could safely use the other two relays to achieve this polarity reversal control of the actuator.
So I'm thinking (out loud) that I'd wire the + from the battery to the COM on one relay, and the - from the battery on the COM of the other relay (actually there is a solar panel controller in there, this isn't really going direct to a battery).
Then using the Normally Open and Normally Closed of each relay I'd achieve the polarity reversal capability depending on the state of the relays, ON or OFF. On paper it seems to look like it might work if there were no inrush or other transitional switching issues. I have to work through the logic again because I'd rather not send power after the limit switches have been hit. That might just be a timing thing to work out because I either want the actuator fully extended or fully retracted, no in-between.
Someone that works with this stuff all the time might be primed to say- "no no no, that's going to cause issues or fry something, this is what you'd use to to achieve this". I'm waitin to hear that if so. Thanks in advance.
EDIT: Refering answers to this to another thread specific to this problem.
