Hello,
I am setting up a small PV solar setup for my boat and would like add some logic control to prevent my batteries going below 50% depth of discharge. Pretty much I just need an industrial grade voltage comparator, which would flick a high current changeover relay between inverter power and shore power hookup depending on the battery bank voltage.
I am trying to use industrial din rail mount controls everywhere as the installation and maintenance is usually easy, robust and straight forward. I do not want to faf around with arduino type setup for the control, so think a simple PLC controller would suffice.
Does anybody work with various PLCs and could recommend which one to go for, which is:
1. cheap (especially could be found easily second hand on ebay)
2. does not need any paid for software to configure it.
I know there are arduino PLCs but they seem to be in a region of >£200 which is above to what I'm happy to pay.
On the other hand, I understand I could mock up some op'amp with adjustable voltage regulator to work as comparator, which is straight forward. What is not straight forward is making sure it is safe (inputs, outputs, fire, etc), so probably a well designed PLC is again a better choice.
Unless there are din mounted voltage comparators I am not aware of?
Other suggestions are more than welcome as well.
Cheers