Power Functions Quadrature Transmission by Mark J E Bellis July 2008 The system consists of: In the transmitting location, a PF handset with crankshaft axle that moves its levers at quadrature phase (90 degrees apart). In the receiving location, a PF battery box, IR receiver and two motors. The motors are geared down 3:1 and then another 3:1 on torque limiting cogs, which accommodate the limited travel of the output shafts. The output shafts turn cranks to push thin beam rods. The rods turn a crankshaft that has its two big end bearings set at quadrature phase. How it works: The input crankshaft turns by 90 degrees. This changes the positions of one or other of the handset levers. The different signal is sent over PF IR protocol. The received signal changes the power to one of the two motors. That motor's crank and push rod move. The push rod turns the output crankshaft. Any parasitic movement of the other push rod is accommodated. The result is that the output shaft turns 90 degrees for every 90 degree turn of the input shaft The pictures show a sequence of movements, with the rack pointer on the baseplate indicating the amount that the input shaft has turned. The accuracy is such that approximately 90 degrees of output shaft movement is obtained, with a wide tolerance. It may be enhanced by gearing up the measured position or angle to the input shaft and gearing down the output. Application: This system may be applied to any equipment where a shaft angle, or a converted linear position, needs to be sent from one rotating or mobile field to another. Models with multiple rotating fields are usually quite advanced. Position feedback from a train to a lineside feature may be more commonly used. It may enable an on-train auto-decoupling device to co-ordinate with a lineside feature that holds the train in place as the coupling is retracted.