JPS6427576A - Trunk protecting guard for karate - Google Patents

Abstract

PURPOSE: To make an accurate judgment on a match via a fair rule by generating a voltage when striking force is applied to the knock sensor of a karate trunk protector during the match, transmitting a warning signal from a transmitter for the voltage of a fixed value or above, receiving the warning signal outside the arena, and generating a waning sound. CONSTITUTION: The knock sensor 1 and transmitter 2 are fitted to the trunk protector for karate. The knock sensor 1 has a function to transduce the shock force by a 'thrust' into an electric signal (voltage impulse). The transmitter 2 is constituted of a comparator 5 receiving the electric signal from the knock sensor 1 and generating a warming signal when the shock force is a prescribed value or above, a modulation section 6 FM-modulating the warming signal from the comparator 5, and a transmission section 7 oscillating, amplifying, and transmitting radio waves based on the FM-modulated signal. The transmitter 2 has a power supply 4 feeding a voltage to the comparator 5. A receiver 3 is installed outside the arena, and it has a function, e.g. a speaker, to generate a warning sound for a fixed period based on the signal radio waves from the transmitter 2. The knock sensor 1 is constituted of a piezoelectric element 8.