Torque Converters (Transmission)
While clutches only convert the speed, the output and input torques however remain the same. Torque converters (transmissions) are capable of additionally varying the output torque against the input torque. This way, the engine characteristic can be approximated to the desired power hyperbola P=const. (Slide 26 shows the ideal characteristic, in which the desired characteristic curves for torque and power are included).