Can someone explain a dynamo problem to me?

Question

Hey guys,

This morning I rode my bike to work and powered the light using the dynamo mounted on the rear fork. I then parked the bike at a bike rack, and when I rode back to the train station this evening, the light didn't work. The wiring on the dynamo was fine, but when I briefly pushed the bike back while parking it, the light came on. Does the dynamo supply power when the bike rolls backward, but not when it rolls forward?

I don't understand how that's possible. Apparently, the pickup wheel on the dynamo continues to capture the momentum from the tire and rotates the magnet in the dynamo. The wiring must also obviously be working. But why does this only work when the pickup wheel is turned counterclockwise and not when it's turned clockwise?

blackhaya · Answer

There's someone plus and minus interchanger

felixlingelbach · Answer

The dynamo is no longer exactly what it is supposed to be. This happens quickly because it's only attached to a single screw. It just happens when parking and parking.

It must stand so that its inner axis points precisely at the center of the wheel.

Two 10 keys are usually needed to adjust it well.

gufrastella · Answer

Hello Sveta Akhatova

Possibly, the dynamide no longer presses sufficiently against the tire jacket in the forward run. You can bend the switched-off dynamo slightly towards the tire jacket so that the contact is permanently given again when the dynamo is switched on.

Because of the generation of an alternating current, the direction of rotation is not necessarily predetermined.

The tire sets the rod in motion, with the rod the magnet rotates and this rapid rotation of the magnet generates a constantly changing magnetic field. This in turn sets in motion electrical alternating current in the wire, which brings the bicycle lamp to light.

https://www.swr.de/know/1000-responses/how-functioned-one-fahrraddynamo-102.html

LG

gufrastella

campawoll · Answer

Bicycle dynamos are not smart like an iPhone, but even extremely stupid.

Although a dynamo has a "preferential" direction of rotation (which adjusts when it protrudes from the frame tube or fork in the direction of travel), it supplies current in both directions of rotation. The fact that a side-runner dynamo faces the rear of the frame tube to which it is attached was not unusual in the past.

Your dynamo problem therefore indicates a simple wobble contact. Whether it's in the outer cabling or inside the dynamo is hard to say.

If the dynamo is still working with single-core cables as before and the return of front headlights and backlight takes place via mass, ie protective sheet, luggage racks, frames and fork, there is very often the cause for the shaker, by grate/corrosion and generally high transition resistances.