New expressions are given in the present paper for the output signals and input power requirements for the three principal torque sensor designs -- the branch, cross, and solenoidal designs.Procedures are described for evaluating model parameters. The parameters are then used in computer-model simulations of the three sensor designs. Calculations are made for each sensor configured to fit into the same space on the same shaft. The shaft was made of either maraging steel or SAE 1010 steel -- both of which have useful magnetostrictive properties.It is shown that for a fixed shaft length, for both shaft materials, largest signal level is obtained from the solenoidal sensor, followed by the branch sensor, and the cross sensor gives the smallest signal. On the other hand, the solenoidal sensor consumes the greatest amount of input power and requires the highest excitation voltage. Physical origins of this behavior are discussed in the paper.