How do I use Magnet Reed type switch to turn on 110 -5amp Alarm?

I am trying to install a reed magnet type switch, on doors/windows, to turn on an alarm. The alarm is 110 volt 5 amp. What I would like is to have a relay to be activated by the opening of the door and a timer to keep the alarm activated for like a minute. This will prevent them from opening up the door, coming inside and quickly closing the door. Get what the want, then exit quickly. The magnet switch eliminates the false alarms created by motion detectors. What I need help with is what specific relay do I need to handle the 110 volts and is there a timer which will activate the alarm to stay on for a set time?

What I would do is use the burglar/theft reed switch style, they can be wired with low voltage wiring and can be wired in series.
Hamlin are one supplier, Digikey should have them.
Most relays or timer relays, out there will switch 110v @ 5amps.
Just need a low voltage supply, bell transformer from H.D. and a bridge rectifier, 12v timer relay.
Max.

With a small external 5 V or 12 V supply, a magnetic reed switch can trigger a timer module from ebay, one that has a relay output. Any spare USB charger will work.

ak