We have an Outback FM60 controller which outputs 0 or 12V as a command, 0 for logic high, and 12 for logic low. I need to invert that for our solid state relay to output 12 for high and 0 for low. Is there a COTS module or assembly that can do this for me?
Figure 1. (a) Connecting an SSR for positive logic. (b) Connecting SSR for negative logic.
From the comments:
If I'm understanding you correctly, no this is coming from the FM60 aux output and is used to control a NC-SSR on and off.
To be very clear:
- NC (normally closed) means that power can flow through the output terminals when there is no input signal.
- NO (normally open) means that no power can flow until the input signal is given.
You have supplied no part numbers for the "NC-SSR" and I have never seen one. All commonly available SSRs are normally-open type because semiconductors require power to turn on. In Figure 1 you need to power D1 before the triac can turn on. See Omron FAQ for more on this. There are some small-signal NC-SSRs.
If this were a typical relay it would work but since it's a SSR, wiring the low signal at 12 V would require a 24 V signal to turn it on not 0 V.
No. See Figure 1.