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Trying To Light A Lightbulb!? Home made generator! Using multiplier circuit!

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CBlol

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Hi,

I am doing a uni assignment and have a few questions.

I made an AC generator using a magnet and a crank shaft to pusht the magnet in and out of a coil.

Using my multimeter, I get a voltage of 1.5V AC roughly (varies between 1 and 2 volts). I wanted to power a mini light bulb with this circuit or preferably magnetize a nail using the voltage I get out.

I hooked the terminals of my generator to a multiplier circuit which then gave ~10V DC on the output terminals of my multiplier circuit. How can I use this voltage to power a lightbulb?

When I connect the lightbulb, the voltage over the lightbulb goes to zero.

This is my circuit:

**broken link removed**

The resistor circled is the lightbulb.

The capacitors are low leakage capacitors I bought at a store. The problem is as soon as the lightbulb is connected, the voltage sinks to zero.

If I put a 10k resistor, I can measure the full 10V drop over the resistor. However, if I put the lightbulb in series or on its own, the voltage sinks to zero.

I can't understand it???? If I put a 100ohm resistor where I have marked on my circuit, the voltage also sinks to zero. With 1k I get roughly the full voltage drop.

Does it have something to do with the impedance of the circuit? Please help me light a lightbulb! :)

Thanks so much!
 
You just aren't making enough power. Multiplying the voltage will not increase the power, it actually uses up power to get through the diodes and capacitors. I think you should try to light a red LED with a diode in series with it and connected directly to V1. It needs about .01 watt to barely light. If you can't get a glow out of that, you will never get an incandescent bulb to light without rebuilding the generator.
 
You just aren't making enough power. Multiplying the voltage will not increase the power, it actually uses up power to get through the diodes and capacitors. I think you should try to light a red LED with a diode in series with it and connected directly to V1. It needs about .01 watt to barely light. If you can't get a glow out of that, you will never get an incandescent bulb to light without rebuilding the generator.

Deleted - moderator

so the problem lies at our generator? nothing with circuitry will up our power or current :<?
 
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Changing the light bulb to a red LED will make you look like you're making more power because it is way more efficient than a light bulb. Try it.

ps, watch the mouth. The bosses here will get after you.
 
How could someone on a Uni course know so little about electicity?, I can only hope he's doing History or something, and nothing electrical or electronic?.
 
How could someone on a Uni course know so little about electicity?, I can only hope he's doing History or something, and nothing electrical or electronic?.

Actually, it's three of us studying electrical engineering in 3rd/4th year doing a university assignment together.

Sorry we weren't born with the knowledge mate.
 
You'd be amazed at what schools do NOT teach. I can zip around any third year student I ever met with 40 years of experience and no electronics courses AT ALL! It's like doctors...they teach everything once and without experience, berri-berri is just as likely a diagnosis as appendicitis.
 
May I suggest that you would do better to improve the design of the generator? Instead of moving a magnet in and out of a coil, either rotate it or rotate the coil in the magnetic field. Also, wrap a coil around the magnet and connect it to the field coil so you have a dynamo. That will convert significantly more of the work you put into the system into electricity.

The Exploratorium in San Francisco has such an arrangement (actually, it’s an old car generator if I recall correctly) connected to a stationary bicycle. I have to pump as hard as I can to generate enough power to light a single bulb. Certainly more effort than I can keep up for more than a few seconds.
 
Actually, it's three of us studying electrical engineering in 3rd/4th year doing a university assignment together.

Sorry we weren't born with the knowledge mate.

I'm even more depressed to find you're 3rd/4th years!.

This was 12 year old physics stuff, not even electronics.
 
Anyway, this experiment looks way better than my zinc-copper plates experiment in a single tray of water. I never thought that the bulb won't light up :p
 
I think you should make a complaint about the quality of your education, it clearly isn't good enough.

Here's a simple voltage doubler circuit which should power a red LED from an AC voltage as low as 750mV RMS.

The value of C1 depends on the voltage and frequency of the power supply, you might also need to add a series resistor to the LED.

You should be able to figure out how this circuit works and what value components to use.

D1 must be a Schottky for optimum efficiency, again you should be able to figure this out for yourself.

EDIT:

With a 1.5V RMS AC supply, you should be able to power a white LED.
 

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