This is a short demo of the punch acceleration sensor i built. Device measures maximum acceleration of the punching board (makiwara) and displays value in g. Hardware used - Arduino (Atmel AVR) board, ADXL193 accelerometer, AD7680 16bit A/D converter. For more info see http://abieneman.wordpress.com/2010/04/03/punch-acceleration-sensor/
Well, i would imagine it's the acceleration * mass of the board + displacement * spring coefficient. As a rough estimate, the board is about 2lb, so if you hit it to 100g, then the maximum force is 200 lbf (same force that acts on 200 lb mass by gravity)
abieneman 1 year ago