I'm designing a burner control for my beer home brew system. I use a plc to control the pumping and will use it for flame ignition and safety also. Iall ready have the ignition parts and I'm looking for a flame safety device with a contact output. I know I could purchase a commercial flame safety relay but that is cost-prohibitive. Does anybody know how a gas clothes dryer flame sensor operates(eBay item 120335493311 at $9.95 is an example)and if it has a contact output? I could probably go to a HVAC contractor and find something in their junk pile but I was searching for a simpler and slightly more elegant solution than cannibalizing a furnace, another option is a flame rod, amp to convert mv to 5vdc and a relay. Or are their any other thoughts for a simple flame safety device with a contact output that is off the shelf and not high dollar.