Physics Demo Number: 160

Approximate

Run Time: 5 min

Hand-Cranked DC Generator, Motor, Large Capacitor

Demo Description

By hooking a hand cranked generator to a large capacitor one may demonstrate storage of energy in a capacitor.

One may also hook the generator to a DC motor and demonstrate conversion of mechanical energy to electrical and back to mechanical.

Scientific Principles

• Spinning wires through a magnetic field can generate electrical power.

• Electrical energy may be directly converted to mechanical energy by running current through wires in a magnetic field.

• Capacitors can store charge for subsequent use at a later time.

Equipment

• Generator

• Capacitors

• DC motor

Equipment Location

• Kit (160) on [B-1-6]

Instructions

The first photo shows the generator(s) along with a capacitor and electric motor for attaching as loads.

Two physically smaller capacitors, but larger capacitance (each 1 farad) may be hooked in parallel and charged by the generator.

One may attach a string to the pulley on the motor shaft and tie the string to a mass to show mechanical work output from the electric energy generated with the crank unit.

Closer views are given by the next two photos:

Writeup created by David A. Burba

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