Appendix; Technical Notes On Cardio Receivers - Technogym Top 600 XTPRO Service Maintenance Manual

TOP 600 XTPRO: Service & Maintenance Manual - rev. 2.0

11. APPENDIX

11.1. TECHNICAL NOTES ON CARDIO RECEIVERS

Technogym utilizes Polar technology for measuring the heart rate frequency of the person training
on the machine. The Polar system consists of:
• a transmitter, worn by the person training on the machine, which uses 2 electrodes to detect the
electrical activity of the heart and transmits the measured heart rate by sending an
electromagnetic signal at a frequency of 5 KHz.
• a receiver, shown in the figure below, which consists of:
− an antenna a, designated the "coil", which receives the signal from the transmitter strap worn by
the user.
− an integrated circuit b, designated the ASIC, which has the function of filtering the analog
signal and generating a pulse train corresponding to the received heart rate.
− two contacts c parallel to the coil, on which a 15 KOhm resistor is sometimes mounted.
The receiver is connected to the CPU board by means of 3 wires for:
− +5 Vdc power supply;
− Output signal (heart rate);
− ground.
The output is a digital signal that is normally at 5 Vdc and goes to 0 Vdc for a few msec when a
heart beat is detected, as shown in the figure below.
Figure 11.1-1
Page 11.1