On Mon, 09 Jan 2017 16:57:48 +0000, Jasper wrote:


Any recommendations for a suitable solenoid : I don't think I need a purpose
built solenoid door bolt - just something to operate off a transformer.

Something like a car door actuator

http://www.ebay.co.uk/itm/Car-Auto-H...AOSwjDZYZLn a

might be suitable with a steel rod going across the track?

It drives in both directions so only needs power when changing state
so overheating is eliminated. It also minimises the problem with
solenoid bolts where the power on force can be quite significant but
changing to the power off state relies on a spring so the bolt has a
tendency to bind if there is any slight misalignment between the
solenoid and door.