I bought this water faucet timer a while ago thinking I could use it as part of a system for watering my plants while I was away. But it requires a minimum water pressure to work properly. Using it inline with a gravity feed system won't work. It's been sitting around here not doing anything for a while now so I figured I should open it up and see what makes it work. Turns out to be pretty simple inside. And by enlarging a tiny hole in a rubber diaphragm, I was able to get it to work the way I originally hoped it would.
When active, the flow rate is something like 2 gallons an hour. That's good enough for me. And it will likely be more with more water in the 5 gallon bucket I use as a reservoir. It leaks just a little bit when shut off but that's ok. So now I can string out some waterline and tee off to a few drippers or something and actual put this thing to use watering my plants when I'm not around.