| 摘要 |
PURPOSE:To prevent the failure of other normal amplifiers due to a failure of one amplifier, in case of a plurality of parallel connections, by detecting the overcurrent flowing to the power amplifier element in a power amplifier in failure and making inactive the control circuit. CONSTITUTION:The output is increased by the parallel connection of a plurality of power amplifiers A1...An. When the output from the power amplifier A1 is absent by a failure in the amplifying circuit 3, the output of other normal power amplifier is fed to the secondary winding of the output transformer 8. Thus, the closed circuit of diode 13 amplifier element 7 primary winding of power transformer 8 is formed, and it is in short-circuit in comparison with other normal power amplifier. Accordingly, short circuit current flows to this closed circuit and overcurrent flows to the closed circuit of power supply 5 fuse F1 amplifier element 7 primary winding of transformer 8 fuse F2 power supply 5 to heat up the amplifier element 7. This is detected by the heat sensing switch 17 in the detection circuit, the control circuit 11 is open with the detection circuit 12 to cancell the said short circuit state. |
