modify a propane detector to turn on a blower

I talked with the seller about the detector signal wires. Supposedly they just close a switch, rated at 750 watts max power. So makes it even easier.
I will keep the info coming.

 

Well than you have a couple of components extra, for playing around, when the envelope arrives at your postbox.

 

Thanks, I got them 2 days ago along with some nice schematic ideas.

 

I am updating the info on this device. It works.
I modified to make it work like I wish.
It has a relay HK3FF DC12V that it uses as a simple switch for the output when it detects gas. The thing is designed so that the relay is NC and is designed to open a circuit that runs to a gas control solenoid. It's default is to be NC so the valve is passing LPG, when it detects LPG leak, relay switched and breaks circuit, so then valve stops flow of LPG.

However, this is backwards, I want to run something when it detects leaks.

It is handy that this relay is double throw switch
http://nb-bole.com/uploads/soft/110419/HK3FF.pdf

So I traced the circuit and figured out which pins work for the other relay throw.
Absolutely verified operation while running and detecting gas for these connection points.

top of board, relay is the black rectangular box


upside down on board, black circles mark the NO connection points to make this work. IF I did not do this, then another relay would have to be energized all the time to make this work.
I plan on using another relay anyway as the bilge blower motor may draw more than 10 amps.


Top of board has attachment point for NO connection to relay. I verified it is same as pin on the back. Shown by black arrow.
I think I will use the back pin as it is easier to get a wire on that point. And less likely I will mess up the circuit, looks tight fit on the front. Maybe.


This device auto resets after it detects gas has cleared. That is ok for my use.

Do you think, Will the sensor also detect gasoline fumes?