1 sec mom input to 5 sec mom output

Whilst request is not specifically for a motor vehicle, as it is 12v I thought some genius here might be able to assist.I basically want to unlock a house door via remote control.So far I have come up with the followinga) Remote relay 12v 1sec momentary output as per http://www.jaycar.com.au/productView.asp?ID=LR8822&CAtid=&keywords=remote+relay&SPECIAL=&form=KEYWORD&ProdCodeOnly= &Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCAtid=b) Door latch (similar to security door locks on some offices)http://www.jaycar.com.au/productView.asp?ID=LA5078&CAtid=&keywords=door+latch&SPECIAL=&form=KEYWORD&ProdCodeOnly= &Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCAtid=Problem: Relay output is only 1 second, and I ideally need 5 seconds to be able to open door.I do not want a latched relay as there is a risk that the door latch will be kept continuously powered and burn out.So, is there a relay combination to convert 1 second momentary input into a 5 second momentary output?Alternatively is there a different remote relay available that can output for say 5 seconds (momentary not latched)ThanksAndrew

There are many ways to do this building a circuit yourself but there is a part available from Directed Electronics (DEI) that will do this cheaply, reliably and best of all EASILY.

Get a 528t pulse timer .    

     It is an adjustable timer-controlled 30-amp SPDT relay (Single Pole Double Throw). The timer is adjustable from 0 – 90 seconds.You can activate it with either a (+) trigger input or with a (-) trigger input. You can set it to extend the one second pulse to five seconds with no difficulty, its done with a small dial on the unit.  It can be wired to put out a +,- or open a circuit...pretty cool piece.

If you don't know where to get one just google "DEI 528t pulse timer" and I am sure a ton of places to send you one will come up.

Hope I helped.

Thanks both for assistance. I have found a supplier here in Aus for the 528t for AU$43 dollars (not quite as cheap as you can get in the US). I may have most of the bits except relay for option 2, but will need to go through all my old electronic gear. Thanks & best wishes to you both Andrew