Abstract: A toilet-flushing control apparatus comprising a detector, a delay circuit, a judging circuit, a first timer, a second timer, and a flush valve. The detector detects that a person is using a toilet, and outputs a signal. This signal is input to the delay circuit. Upon lapse of a predetermined time after receiving this signal, the delay circuit outputs a signal. The output signal of the delay circuit is supplied to the judging circuit. When the output signal of the detector lasts shorter than a reference time, the judging circuit determines that the toilet user has urinated. Conversely, when this signal lasts for the reference time or a longer time, the judging circuit determines that the toilet user has defecated. In the first case, the first timer is operated, and the flush valve opens for the time set to the first timer, thereby flushing the toilet. In the second case, the second timer is operated, and the flush valve opens for the time set to the second timer, thus flushing the toilet.

Abstract: An automatic flushing system for flushing a plurality of toilet bowls with water, which is provided with a solenoid-controlled valve and a detecting device. So long as the detecting appliance detects no toilet user, the solenoid-controlled valve is opened every time a predetermined time lapses, thereby to flush all the toilet bowls. If only one toilet user is detected, the solenoid-controlled valve is opened thereafter upon lapse of a reference time shorter than the predetermined time, thereby to flush the toilet bowls. If two or more toilet users are detected, the solenoid-controlled valve is opened thereafter upon lapse of a time shorter than the reference time, the time being shorter by a predetermined length for each additional toilet user detected.