My wife has cracked her head on our kitchen cupboard doors a number of times. I decided to install an alarm that nags her when she leaves one of those darned doors open. So I sent away for Magnetic sensors for the doors, a multi-functional time delay relay and I had a buzzer. After all the stuff arrived, I tapped into a 12 volt source and wired all this stuff up.
The Multi-functional time delay relay is made in America. It can be programmed to delay turning something on or off, or it can be programmed using a trigger event. It can also make things flash. There are 19 different programming modes for this little device. Costs less than $20 and can be found on EBay.
It's a little bigger than a postage stamp and has several wires coming out of it for the purpose of controlling voltage events.
Find this device at: http://www.3rdbrakeflasher.com/timer-c-68/
The Multi-functional time delay relay is made in America. It can be programmed to delay turning something on or off, or it can be programmed using a trigger event. It can also make things flash. There are 19 different programming modes for this little device. Costs less than $20 and can be found on EBay.
It's a little bigger than a postage stamp and has several wires coming out of it for the purpose of controlling voltage events.
Find this device at: http://www.3rdbrakeflasher.com/timer-c-68/