Monitoring Device of Horsepower Rating

Measuring the torque in an automobile drive shaft is the purpose of designing this horsepower monitor device which can provide an output to a portable computer via an RS232 interface or a vehicle data recording system.

The sensor unit and the receiver unit comprise the whole system wherein the sensor unit attaches to the driveshaft while the serial output signal is provided by the receiver unit. A battery is used to power the sensor unit as it communicates through a 433MHz RF data link with the receiver while the vehicle electrical system is used to power the receiver unit. To calculate the horsepower, the received data can be combined with RPM measurements from the data recording system.

A cylindrical housing encloses the sensor unit and is split along its axis so that attachment without access to the driveshaft end would be allowed. The torsion is transferred to the housing endplates when the driveshaft experiences it because the sensor plate is attached to the outboard end plate it moves with. A signal, processed by MCU circuitry and proportional to the driveshaft torque is produced by the resulting angular deflection between the magnet and sensor.