Although not what we do, a guy once brought an electric motor driven siren from a fire engine in the front door to see if we could convert it from 6V to 12V. Being as close to an expert on such things as we had, the siren ended up on my desk.
Well..... I just had to test it. I put on my ear protection and fired it up with a bench power supply.
Even with the door closed, and the concrete block walls around my office, and the poured concrete floor of the conference room above, everyone thought the tornado siren up the street was going off.
After an amusing distraction, I sent it back, saying no, we couldn't help the guy, and went back to more important but less enjoyable tasks.
Weston Bye - Author, The Mechatronist column, Digital Machinist magazine
~Practitioner of the Electromechanical Arts~
Theory & Practice-
Theory is when you know something but it doesn't work.
Practice is when something works but you don't know why.
It it dangerous to combine Theory & Practice;
nothing works and you don't know why.