Patent ID: 7348690

Claim:
A device including a control, said device having a first energizing circuit, said first energizing circuit containing at least one first transducer, said first energizing circuit containing a plurality of first switches, said device including circuitry allowing said control to operate said first switches, said first transducer requiring a first current to be energized, said first switches capable of carrying said first current, said device including a first sensing means to scan said first energizing circuit, said first transducer having a potential to cause said device to operate in a hazardous manner if said first transducer is mistakenly energized, said first transducer never causing said device to operate in a hazardous manner when said first transducer is in an unenergized state, said first energizing circuit having first idle periods throughout which said first switches are expected to be open, said control using said first sensing means to; identify each of said first switches as either first functional switches or first erroneously closed switches during said first idle periods, identify any of said first switches as said first functional switches that said first sensing means verifies are open during said first idle periods, identify any of said first switches as said first erroneously closed switches that said first sensing means verifies are not open during said first idle periods, said control using said first functional switches to preclude said first current from flowing through said first erroneously closed switches, preventing said first transducer from being mistakenly energized.