Help building a latch trigger

[FiremanMSmith]

I am trying to build a trigger for a small latch. I am thinking of using a mercury switch to trigger a linear solenoid that extends to operate the latch.
The voltage needs to be DC. Any ideas?

 

[Dotnet]

Hi FiremanMSmith and welcome to the site!

Like everything in life there are many ways to do/achieve the same thing so please bare with me.

Could you give a little more indication on the application/forces involved as this depends on rating, number of windings etc of the solenoid and consequently the voltage. (Basically)

One problem you might have is that a mercury switch could quickly close then open again without giving time for the latch to open therfore a time delay (monostable configuration on a 555) might need to be considered.

Alternatively a linear actuator (again with a monostable) and a form of cross-over relay be more suited if higher forces are expected, at least then you are guaranteed to move the latch 'completely' after triggering.

Sticksion must also be considered!!!!

Where are you based - it is not in your profile.

Regards
Matt

 

[FiremanMSmith]

Thanks for the response.
More info.
I am in the process of building a humane live trap that will catch multiple racoons. My plan is to have them stand on a trap door that will open only when the switch is activated. The door will be held shut by a latch similar to one on a storm door. The door must be solidly in place until the full weight of the racoon is on top of it. I know there are many ways to trigger the latch, but my electrical experience is very limited. Basicaly the door will have up to about 20 lbs when the latch needs to triggered. The forces needed to work the latch should be less because of the leverage of the latch handle. Any help is greatly appreciated...........Mitch

I will update my profile, but for now, I am in the US. Searcy Arkansas to be exact.