Greetings from a first time poster and electronics novice. I have been searching and reading up on solutions to my project for the past hour or so and think I may have some direction, but I'd like to get some advice before I end up moving in a direction that may not be the best.
My project: We have a security system at our office building and each desk has a button wired in to the system that will unlock the front door for 8 seconds. The security company wired in a buzzer that will activate as long as the door is unlatched. Even if someone opens the door the buzzer stays on, which is confusing for the customers and annoying for everyone else.
Here is what I have to work with: When the button is pressed, a 12v circuit is activated for 8 seconds that drives the buzzer directly. I'm not able to access/modify anything on the security system, all I have is the 12v circuit to work with and it is separate from the door lock mechanism so I can do what I want with it and not affect the locking mechanism.
Here is what I'd like to accomplish: The buzzer activates until the door opens. Once the door opens, the buzzer stops for at least 8 seconds until the security system closes the latch on the front door and disconnects the 12v power to the buzzer.
Here is what I'm thinking: Installing a magnetic door switch between the 12v source and the buzzer and integrating a 555 one shot circuit inline that will keep the power from the buzzer for at least 8 seconds. Is this something that sounds reasonable? If so, are there any suggestions on what I should know before going into this? Any suggestions on how to integrate the 555 timer? Any help or direction would be greatly appreciated.
My project: We have a security system at our office building and each desk has a button wired in to the system that will unlock the front door for 8 seconds. The security company wired in a buzzer that will activate as long as the door is unlatched. Even if someone opens the door the buzzer stays on, which is confusing for the customers and annoying for everyone else.
Here is what I have to work with: When the button is pressed, a 12v circuit is activated for 8 seconds that drives the buzzer directly. I'm not able to access/modify anything on the security system, all I have is the 12v circuit to work with and it is separate from the door lock mechanism so I can do what I want with it and not affect the locking mechanism.
Here is what I'd like to accomplish: The buzzer activates until the door opens. Once the door opens, the buzzer stops for at least 8 seconds until the security system closes the latch on the front door and disconnects the 12v power to the buzzer.
Here is what I'm thinking: Installing a magnetic door switch between the 12v source and the buzzer and integrating a 555 one shot circuit inline that will keep the power from the buzzer for at least 8 seconds. Is this something that sounds reasonable? If so, are there any suggestions on what I should know before going into this? Any suggestions on how to integrate the 555 timer? Any help or direction would be greatly appreciated.