Safety device for sensing preventing radiation leakage from microwave-producing apparatus

Claim 1

A safety device for sensing and preventing radiation leakage from a microwave-producing apparatus comprising in combination: a first series branch including at least one gas-tube which is sensitive to microwave radiation and is located in a region of possible microwave radiation leakage, a first relay coil electrically connected in series with said gas-tube and arranged to operate a first set of contacts which are inserted in a power supply circuit of the micro-wave producing apparatus so as to break the power supply to the micro-wave producing apparatus upon de-energization of said first relay coil, and means sensitive to current passing through said first series branch; a second series branch connected in parallel with said first series branch and including a controlled diode and a second relay coil connected in series therewith, the second relay coil connected to operate a second set of contacts which are inserted in said power supply circuit so as to break the power supply therein upon energization of said second relay coil; and a d.c. source supplying direct current to said first and second series branches, whereby, upon the gas-tube sensing microwave leakage, the power supply to the microwave-producing apparatus is interupted.