I'm not the sharpest tack in the box on this stuff so any help appreciated.
At 70+ years there must be a lot of shorts upstairs.
In running a pair of CMOS 555s in a door alarm with a wall wart and battery backup, is there anyway to prevent the circuit from resetting when the power is interrupted by pulling the jack out or unplugging the wart? The power transisition does work ok but must produce enough of a delay to cause the reset.
I am using LMC555CN in astable mode, pin 7 open and 2 & 6 tied to an RC network for a 15 sec delay for adults to move in and out the door without setting it off. It is wired "always on" and when needed is reset thru a switch driving 2 low. The 2nd IC gets its input from the output of the 1st.
The battery connections are wired direct to the jack's outputs. Pin1 shares the pos. with the wart & Pin3 gets the neg.
I also have tried using 2 steering diodes to direct the pos. but without success.
At 70+ years there must be a lot of shorts upstairs.
In running a pair of CMOS 555s in a door alarm with a wall wart and battery backup, is there anyway to prevent the circuit from resetting when the power is interrupted by pulling the jack out or unplugging the wart? The power transisition does work ok but must produce enough of a delay to cause the reset.
I am using LMC555CN in astable mode, pin 7 open and 2 & 6 tied to an RC network for a 15 sec delay for adults to move in and out the door without setting it off. It is wired "always on" and when needed is reset thru a switch driving 2 low. The 2nd IC gets its input from the output of the 1st.
The battery connections are wired direct to the jack's outputs. Pin1 shares the pos. with the wart & Pin3 gets the neg.
I also have tried using 2 steering diodes to direct the pos. but without success.