Matsushita Electric Industrial Co., Ltd.

Masao Itou

Katsuhiko Yamamoto

Makoto Hori

Hidenosuke Matsumoto

Takaaki Nobue

Horoshi Horii

Toshio Marumo

The timer circuit of the present invention comprises a comparator, which, in the example of the air conditioner, compares the room temperature measured by a thermistor with a predetermined value and charges the timer capacitor of the timer circuit when its output is in ON state, and makes the capacitor discharge when its output becomes in OFF state; thereby the timer circuit can produce the first set time, for example, by the abovementioned discharging time, in this first set time a compressor circuit being made OFF for prevention of overloading due to a too-early restarting, and furthermore, with utilizing the same timer circuit with a modified predetermined value of the comparator thereby producing subsequent cycles of charging and discharging and accumulating a predetermined number of repetition of the cycles, a desired longer time for the second time can be produced.

Operation time control apparatus

An ultrasonic generator comprising an ultrasonic transducer having a natural frequency at which the dynamic admittance becomes maximum; a main circuit consisting of a switching circuit or first current regulator and a second current regulator connected in series to said switching circuit or first current regulator, the ultrasonic transducer being interconnected between an electrical source and the junction between said switching circuit or first current regulator and the second current regulator; a driving circuit for alternately driving the switching circuit or first current regulator and the second current regulator at a frequency equal to or substantially equal to the natural frequency of the ultrasonic transducer, thereby supplying the driving current thereto; and a feedback circuit for deriving an AC voltage in proportion to the magnitude of the driving current and feeding back this voltage to the driving circuit.

Ultrasonic generator with combined oscillator and current regulator

Growing community of inventors

Nara, Japan

Masao Itou