Present day torque converters use electro hydraulic Management for that lock-up clutch. The hydraulic circuit which locks/unlocks the torque converter clutch is managed using hydraulic valves. The valves are actuated straight or indirectly by solenoids. These electricity conversions appear with a few losses. These loses are generally because of friction https://torque-converter-clutch20741.blog-a-story.com/14738701/a-review-of-torque-converter-clutch