I had one of those BB generators in the 80's*, A toe touch to the lever releases it onto the tire , without stopping.

*got a British remanufactured version with a rubber strip around It. since the metal drum invariably slipped on a wet tire.

I think they were DC, (+ wire, frame ground) so may be incompatible with LED headlights
run from Hub Dynamos which now are AC.

[I did not have an Oscilloscope available to confirm AC] ( 1 hot+ wire and thru the frame cold- and ground is possible)

E Bike LED's I think leave out the rectifier chip, since they use the battery that powers the motor.

I ran Mine off Bulbs , Union Halogen 2.4w. regular tungsten 0.6w taillights .