| 摘要 |
PROBLEM TO BE SOLVED: To provide a PWM controller which drives the base of an IGBT (insulated-gate bipolar transistor) according to a digital system, in which a temperature drift is eliminated, in which an externally attached element is not required, which can perform a variable dead-time compensation, which reduces the load of a microcomputer by a three-phase generation circuit to generate the other phase from two phases in three-phase sine-wave data and which saves the capacity of a waveform ROM. SOLUTION: A dead-time compensation circuit 4 which is operated according to a digital system is operated for a definite time by timing pulses from a microcomputer so as to be set to a reset state, and it is synchronized with the timing of a timing generation circuit 1 which generates the reference signal of a digital PWM control apparatus. In addition, by making use of a fact that the sum of three-phase sine-wave data is always zero, the generation of three phases is computed by a three-phase generation circuit 7 which is constituted of an adder and of an inverting circuit. |
