I am currently working on a project where I am creating a faraday flashlight. The project applies the laws of electromagnetism where a magnet moving through a coil induces an alternating current.
After hooking up the coil to a multimeter I am reading voltage values below 1, but the system is still able to light the common LED, which I thought had an operating voltage at least greater than 1V. Why is this occurring? Am I using the multimeter incorrectly and must be getting higher voltages or is the LED able to work on 0.25 to 0.5V?
All LEDs are CURRENT operated devices, not voltage. To limit the current through a LED, a resistor is used in series with the LED.
Your device creates enough current to operate the LED, but not enough to burn it out.
What do you mean by current operated devices? Won't there always be a minimum required voltage even if the required current is provided? How can I measure the current generated by the coil with my multimeter?
If the voltage doesn't matter does that mean I'm generating at least 10 mA because the LED turns on?
Thanks
Research LEDs. How they were discovered/developed and how they operate. They are NOT a single device, but some microscopic part will begin to emit light when current flows. More current, more molecules will begin to emit. Not all molecules will emit at the same current. As they begin to emit, the break-down voltage drops to zero, so some limit is necessary to keep them from immediately going dark!
The multimeter averages the input voltage over some period of time.
The LED has an exponential voltage-current relationship.
Remember that the coil will be producing an alternating current. Positive voltage when the magnet moves in one direction, negative when it moves the other direction. A single LED will light up with one polarity of voltage, and block any current flow in the opposite direction (at least until it reaches its breakdown voltage, at which point it will conduct, but the current will likely not be enough to cause any damage in this case).
Thanks for the reply. I looked more into it and from my understanding there is no minimum current to light the LED, and as more current is passed, more photons will be emitted, eventually at the threshold when it is visible to the human eye.
When connecting it to my multimeter and shaking the coil tube I am reading a current of about 50 mA. So I am assuming that the LED is not frying without a resistor even at this current because the voltage is low?
My next step is to store the current rather than light the LED immediately. I plan to do this with a 3300 uF capacitor. How can I calculate or figure out how long it will take to fill this capacitor with 50 mA of current and around 0.75V?
I am getting readings that fluctuate between 0.5 to 0.75V when shaking the coil tube rapidly.
Those won't be the peak voltages.
Yes thanks I will be adding a full bridge rectifier to convert the A.C to D.C.
You need to use an oscilloscope to see the actual voltage/current being created. The DVM will average the readings over about a second, so will be impossible to indicate the instantaneous voltage/current being created by your device.
Oh okay so if the neutral voltage is around 0.75V is there no way to estimate the max and min amplitudes for the voltage?
The diodes will drop around 0.6V each, so 1.2V, and the LED probably won't light.
A total voltage drop of 1.2V? Then I will have to add way more coils to the tube, maybe double it correct?
For a flashlight, there is no need for a bridge rectifier. Just use two LEDs in parallel, but connected with opposite polarity. One will light for each direction of the current flow.
I considered that but my goal is not to just constantly light the LEDs while shaking. I want to store the current in a capacitor and then have the LED stay on for a brief amount of time. Would the LED still light from the capacitor without the bridge rectifier?
Shaking like a madman and the white LED barely turns on 
Then your generator is not very efficient.