I am looking for a device that once 12vdc is applied a 10-15 second timer is started to initiate a momentary closure. No power transfer just a momentary closure of .5 seconds. Anyone know of something simple? Thanks in advance.

 

You can implement this project with an Arduino or any other microcontroller.

 

Or you can use an LMC555 timer circuit.

 

I dont know if you have availibility of components where you live, but if you can buy an OFF DELAY TIMER RELAY that should solve your problem.

 

Not knowing what the load is?

A simple Google of "timer relays" will bring up a dozen hits of modular off the shelf inexpensive timing solutions including delay on make, delay on break, repeat and one shot as well as others.

Ron

 

To make the intention clear, you seek a timer that after a variable delay of 10 to 15 seconds after power is supplied, provides a contact closure for 0.5 second. Then the contacts remain open.

 

What is the open-circuit voltage across the "closure" circuit / device / whatever - ?

What is the closed-circuit current?

ebay timer module with isolated relay contact outputs - approx. $5 US.

ak

 

Getting a half second pulse will require some sort of second timer function, which may add some complexity to the project.
How accurate do the time periods need to be?? And what sort of load current will the contacts be controlling? There is a really simple trick to get a single pulse, if the load is isolated and at a specific voltage.