How come my relay switch for an alarm I built only works for a few seconds?

Thursday, June 24th, 2010 at 3:36 pm

I built a latched alarm using a relay switch. The first one I built works fine, but after copying the circuit, the new latched alarms I built only stay on (latched) for a few seconds. I have a 40A 12V relay and a 12V 1.5A power source. Thank you for your help.