PURPOSE: To easily perform division with high precision by performing pulse width modulation in inverse proportion to one of two analog signals and modulating the amplitude of this signal with respect to the other analog signal and averaging this signal.
CONSTITUTION: A duty variable free-running multivibrator outputs a pulse signal (c) whose duty ratio is changed in inverse proportion to the amplitude of an analog input signal A. This signal (c) is subjected to pulse width modulation in inverse proportion to the amplitude of the input signal A. The signal (c) subjected to pulse width modulation has the pulse width kept as it is but has only the amplitude changed in accordance with the amplitude of an input analog signal B by a pulse amplitude modulating circuit 2. If the input signal B has the same sine wave as the input signal A, the modulating circuit 2 outputs a signal (d) obtained by changing the peak value of the waveform of the signal (c) in accordance with the amplitude of the waveform of a signal (b). With respect to this signal (d), a pulse signal having a certain frequency is subjected to pulse width modulation corresponding to the input signal A and amplitude modulation corresponding to the input signal B. This signal (d) is averaged by an LPF 3 to obtain a division signal (e).
TAKAO KATSUTOSHI
KUSADA TOKUTARO
