A disjoint control system using an ultrasonic wave is provided to allow a signal of a predetermined frequency to pass a band pass filter by designing the band pass filter using RLC parallel resonant circuits coupled in a condenser coupling scheme. A disjoint control system using ultrasonic wave comprises an RLC parallel resonant circuit(305). A signal passes through both a limiter amplifier(303) and an RLC parallel resonant circuit(305) so as to be applied to a frequency output part(306) from which a plurality of desired frequencies are output. The output signal passes through an integrator(307) and is applied to a variable reference-voltage comparator(308). The output signal is applied to a disjoint/response signal generator(309) embedded in a controller. The frequency output part divides and outputs signals having a plurality of frequency bands using the RLC parallel resonant circuit.
