Electronics is not my forte, so bear with me on the nomenclature.

**Backstory**

We have an old house and my wife bought me some [old butler bells](https://www.doorhandlecompany.co.uk/prima-butlers-bell-on-black-spring-with-shaped-oblong-enboss-26591/) to get going as our door bell.

[![enter image description here](https://i.stack.imgur.com/bIg1A.png)](https://i.stack.imgur.com/bIg1A.png)

I found a motor which turns a handle to throw the bell left and right and when it's on, it needs to be on for a few seconds for the momentum to build up and ring properly.

Now, I can have a door bell button and if I hold it on for 4-5 seconds, the bell rings nicely. However, I have this old door bell puller. I have a momentary switch installed at the back of it so, at rest, the switch is pressed and no power flows (momentary off??). When you pull the handle, the switch is open and power flows while you pull it. This works, but I've found most people when they pull it, they just let it go. So I want to do something that allows power to flow for a minimum of 5 seconds, whether I pull it once and let it go or for longer. Obviously if I pull and hold for 10 seconds, it should ring for 10 seconds.

**Question**

What can I add to a momentary off switch, to allow it to run for a minimum of 5 seconds on one press/release?

Thank you.

Update from the comments. This is all about 12v from a normal doorbell transformer.