On Wed, 29 Jun 2011 23:58:23 -0400, aemeijers wrote: ....
I found out years into it that whenever someone rang my doorbell when I wasn't home, usually the mailman, it set off my burglar alarm. Most people weren't home and no one complained. It just came up in conversation.
I foudn a nicer doorbell on sale for 60% off, so I bought it and put the other one in the basement. Then it turned out I needed a bigger doorbell transformer to run both, and when I got the bigger one it rang the main floor bell louder than the previous bell had rung, which set off the glass/wood breakage detector, and the alarm.
Didn't want to make the two detectors less sensitive, so I put a resistor in the power supply to the main floor bell. Used a potentiometer until I got a good value, measured the value of the pot at that point, and replaced it with a fixed resistor.