The mechanism:

To make sure that the dynamo does not destry the LED which is driven by the DC motor, which is this case works a  generator, it was nessecary to either design more complex mechanics or implement an electrical circuti which solved the same problem

First part consisted of make the alternating current into direct current so we could make the LED shine. A diode bridge was therefor set in afte rthe DC motor, as shown on the circuitdiagram. Luckily it was possible to find an encapsled diode bridge so it was only 4 terminals which should be connected in the final print. The output form the diode bridge is in form of a direct current. The datasheet for this component is included in the sources.

To make sure the input voltage for the LED was stable the first idea was to insert a 7805 voltage regulator, to make a stable outout of 5V. Only problem is that the component itself uses a lot of energy and is therefore not suited for being used for this task. Configuring the 7805 would also require a small handfull of components extra, but not an solveable obstacle for the design.

Instead the solution was to implment a zenerdioder mounted in opposite direction of the possitive output of the diode bridge. The breakdown voltage of this component is used in correleation with Kirchorfs law to make sure the component in parralel also has the same voltage. A resistor is also mounted to regulate the current the LED has available.

A capacitor was mounted in between the Zener diode and the diodebridge, to smooth out the output voltage from the diode bridge. The bigger we choose this capacitor the longer it will take before he LED lights, but also how long the LED can light without input from the diode bridge, since the capacitor will give off it’s charge to the diode. A large enough capacitor would in combination with a on off switch work as a rechargeable battery.


2 tanker om “Mechanism

  1. Interesting! could be great with a picture / diagram showing how it works..
    And i am not sure if the led would be destroyed if connected to the motor directly…

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