Shaft torque meter with digital read=out - detects phase difference between inductive transducers attached to shaft

The shafts torque meter consists of two toothed wheels which are attached to the shaft in question at two different positions(1, 5). The toothed wheels operate in conjunction with inductive pick-up coils(7, 9) whose output pulses are amplified(11, 14) and passed to an exclusive-nor gate(17). The output of this gate is connected to one input of an orgate(20). Its other input is taken from a phase-locked loop (23, 25, 27, 30) connected to the output of one of the pulse amplifiers(14). This amplifier output is divided(40) and drives a hold circuit(45) and, via a delay(43) a counter(37) and divider(35). The phase difference between the two toothed wheels, and thus the torque in the shaft, is converted to pulse form to be processed in the above logic stages. The hold circuit delivers pulses to drive a digital display(53) and an analogue signal is available at the output of a digital-analogue converter(55).