principles of operation of bicycles, generators, dynamos

The bicycle electrical power supply is in a few different methods but this section will treat the method where a dynamo is used. A dynamo is a generator but supplies direct current (D.C.) only. The other generator is referred to as “alternator” because its output is collected via slip rings instead of split rings or commutators.

Operation: The dynamo is hinged for huge movement but with a firm bracket. When in use, it is pushed against the cycle tyre on its nulled rubber cap which is free to rotate at the pedaling speed of the rider.

The armature and the commutator rotate between the carbon brushes are in a fixed position so that the conductors situated at a right angle to the magnetic field always release its current to the same brush therefore maintaining same polarity of the generated output e.m.f. i.e. polarized + and – (D.C.) similar to a battery.