First blizzard warning in Wisconsin for over 10 years and our furnace decided to stop working this morning. At least I was home because of the weather. Still had to drive a hr round trip in the snow and hope the after market sensor works. It is, for now…
Here is how I see how the flame sensor works in my mind:
Is it a flame? 🔥 Yep. Return signal.
That’s how I do it too.
MCP: Is there a flame?
Me: *checks, sees flame*
Me: Yup.
End of line.
I always thought it neat that the flame acts as a rectifier to create a dc circuit from AC.
According to wikipedia most of them work by detecting light :)