i am currently doing an electronics project which has a reed switch which activates a door alarm for 4 minutes. However, i would like the owner using the alarm 30 seconds to leave the room. i have used a 555 timer monostable to do this and have used a 555 timer monostable to create a 4 minute alarm when the reed switch is broken.
Can anybody help me link the two systems together using a not gate etc.
when the first switch is pressed in my first 555 timer to enable the 30 second turn on delay,onlt then do i want the second 555 timer, which has the reed switch to work. when the reed switch is broken a buzzer or led will sound or light up.
i am using 9v supply.
Can anybody help me link the two systems together using a not gate etc.
when the first switch is pressed in my first 555 timer to enable the 30 second turn on delay,onlt then do i want the second 555 timer, which has the reed switch to work. when the reed switch is broken a buzzer or led will sound or light up.
i am using 9v supply.