flickering sound activated light

[mommyof3]

I am looking for the best (and easiest) way to hook a light bulb up to a microphone that it would flicker when you speak into the microphone. I am wanting to put it inside a pumpkin to give it the illusion of the pumpkin talking. Any assistance would be greatly appreciated

[awright]

You are describing a LIGHT ORGAN.  This is a device that modulates the power to one or more lights in response to audio input to the device.  While the basic components of such a device are relatively simple and straightforward, I believe that your best bet for getting one up and running by Halloween is to buy a light organ kit.  There are lots of them out there.  Google "light organ kit," and you get more than 3 million hits.

Watch out for kits that require input from an audio power amplifier.  This is the most common configuration due to the primary application of such kits.  Since I gather that you want the light organ to be driven from a microphone, you would need a microphone preamplifier to drive such a unit.

Since you are not looking for multiple colors controlled by different portions of the spectrum, which complicates the device, pick one described as a, "single channel" kit.  A single channel light organ drives only one lamp or cluster of lamps or LEDs in response to a single audio signal.  Multiple channel light organs control multiple light sources of different colors from different portions of the audio spectrum.  I gather that you are not looking for that type.

You can get single-channel light organ kits in the $5 to $50 range.  Velleman is a very good kit maker.  Here's a $5.95 Velleman kit  (http://store.qkits.com/moreinfo.cfm/MK103) that powers 4 red LEDs mounted on the board and has a microphone built in on the board.  Looks perfect for your project if you wanted the microphone inside the pumpkin with the light source.  Consider substituting ultra-bright white LEDs for the red LEDs provided with the kit.  You can get the ultra-bright LEDs from Digi-Key or Mouser or possibly your local Radio Shack.  You will need a power supply in the range of 8 volts to 15 volts DC.  Since the kit consumes from 0.5 to 20 milliamps (depending upon the instantaneous intensity of the light), you could probably get by for a few hours on a 9 volt alkaline "transistor" battery, which would make the whole thing self-contained with no power cord.  You can conserve battery power by adjusting sensitivity to avoid having the LEDs on most of the time.

Have fun.

awright