Most torque converters have a stall speed around 2000 - 2500 RPM. Which also happens to be the RPM range that your vehicle normally runs at cruising speed. At a lower speed you would be simply running a viscous coupling between the engine and transmission.
Then, thereâs the obvious choice: A dynamo attached to one of the bike wheels. (These devices in general are called generators, but when attached to a bike, a generator is traditionally referred to as a dynamo.
A washer with a key to prevent rotation, and is used to lock two nuts in place, without allowing the torque applied to the top nut to cause the bottom nut to also rotate (such as in a threaded headset on a bicycle).