A regular gate latch is the most common I've seen used this year with a separate tiny cylinder to unlatch it.
If you do the precharge trick don't pull the cylinder all the way back when it latches. Leave a couple of inches of cylinder as precharge volume.
You can also do a variation, such as
- using a cylinder to pull back a heavily elastic powered kicker
- latching it back
- returning the cylinder to it's forward position
- opening the latch to kick
- repeat.