| 摘要 |
PROBLEM TO BE SOLVED: To follow abrupt change in real time even when the change accompanies occurrence of abnormality.SOLUTION: A digital amplitude modulation device of an embodiment comprises: a calculation output unit which is configured as an analog circuit and calculates a protection index for an amplifier on the basis of a synthesized output signal or an amplitude modulation signal to output the protection index; a first protection unit which is configured as an analog circuit and outputs, on the basis of the protection index, a first control signal for making all amplifiers of an amplification unit be into an off-control state, to a control unit when receiving the protection index; a second protection unit which is configured as a composite circuit of an analog circuit and a digital circuit and outputs, on the basis of the protection index, a second control signal for controlling the upper limit number of amplifiers of the amplification unit capable of being into an on-control state in parallel and a third control signal for performing on/off-control on amplifiers of the amplification unit in the initial state or under the condition that the number of the amplifiers is within the upper limit number, to the control unit; and the control unit for performing on/off control of a plurality of power amplifiers on the basis of an input voice signal, first control signal, second control signal, and third control signal. |
