Roboter mit Aufprall-Fühler (Schildkröte)

The sight of so many interesting and diverse circuits contained in one issue may well lead to a quickening of the pulse rate for some of our readers. However, we have taken this into account by including the following design for a digital heart beat moni· tor. The circuit measures the time interval between successive beats of the heart and then calculates the heart rate in beats per minute before displaying the result on a three digit LED display.