+1, I see often these on ammonia control systems. Takes a 4-20mA signal and does the complicated part for you.Here's exactly what you want
https://buildings.honeywell.com/us/...4e19011eb82a4c42b0a82b839&cjdata=MXxOfDB8WXww
What is the controlled parameter? Is it
- valve position (e.g. 0-100%);
- valve velocity (e.g. ±X%/s);
- valve direction (e.g. ±K%/s)
- K = constant magnitude of valve velocity,
- 3-state control i.e. opening closing, or stationary?
This does not sound like a place for a roll-your-own solution. Many things can go wrong. If you don't have a flame sensor you run the risk of allowing a buildup of unburned gas, a potential explosion. If you don't also control the flow of combustion air you run the risk of a buildup of CO. Both of those scenarios can kill people. That's why people are recommending you purchase a burner controller from a reputable source.
thanks,
valve position =0-100%
valve velocity=0-30sec. full close to open time
it is open and close