Is it possible to convert DC Current into an audio signal?

Question

I realize that DC current does not alternate and therefore technically would not create any sound, but all I need is an audio representation of the amount of DC current flowing to a motor. Sort of like voltmeter that provides sound instead of a number for its readings. I have looked into using a DC current converter to power a tone oscillator, but the project seemed a little too complex for me. If any one has any ideas, or even knows of a multimeter that has an audio output, please let me know! Thanks!

I have limited electronics knowledge... I built a few VERY simple circuits (Blinking LED's, etc) in high school, but I don't have the same resources now that I did then. The purpose of this conversion is to turn the signal sent from a video game to the "rumble" motor in the controller (basically DC current to an electric motor) into sound that can be fed to a device called a Buttkicker LFE (www.thebuttkicker.com), which is basically a vibrating motor that is activated by low end (bass) frequencies. I would definately use some sort of IC chip in a cirucuit if I knew how, but most of the instructions for voltage to frequency converters seem way over my head.

Answer 1

There are lots of Voltage-to-Frequency converter IC's available -- that's their job to convert voltages (i.e. currents through a resistor) to a known frequency, so the voltage (or current) can be measured.

Here is one that doesn't need alot of external components:
http://www.analog.com/UploadedFiles/Data_Sheets/AD654.pdf
There are example circuits near the end of the datasheet.
.

Answer 2

Use a VCO. Voltage-controlled oscillator
From Wikipedia, the free encyclopedia

A voltage-controlled oscillator or VCO is an electronic oscillator specifically designed to be controlled in oscillation frequency by a voltage input. The frequency of oscillation, or rate of repetition, is varied with an applied DC voltage, while modulating signals may be fed into the VCO to generate frequency modulation (FM), phase modulation (PM), and pulse-width modulation (PWM).

You could then feed the output of the VCO into an FM receiver and receive ouput frequency vs DC input

Here is an example of one that is available:

Publication: Microwave Journal
Publication Date: 01-MAR-04
Format: Online
Delivery: Immediate Online Access

Article Excerpt
The model CRO3120A is a voltage-controlled oscillator that utilizes a ceramic coaxial resonator. The model operates at 3120 MHz and offers good phase noise at -114 dBc/Hz at 10 kHz offset. With low tuning sensitivity of 7 MHz/V, this oscillator offers minimal susceptibility to pushing and pulling: < 0.5...

Answer 3

Since you do not have the "means" to build some voltage-to-sound generator, this is what I would do:
Take an AM radio (not FM) with the dial where no radio station is, and put it (better: its ferrite bar antenna) as close as possible to the DC motor and turn the volume up. Then run the motor. The (usually unwanted) Electro-magnetic interference from the motor will be picked up by the AM radio.

Answer 4

Using Ohm's law, I=V/R you can correlate current to voltage by reading the voltage off of a precision 1 ohm resistor in line with the motor. You can then configure a 555 chip to change frequency with response to voltage (see chip reference pages from manufacturer) This frequency can be amplified and sent to a speaker. Relatively easy project.

Answer 5

If you just want a tone when some voltage is present you can buy off the shelf buzzers. Apply a DC voltage and it makes a noise. Hope this helps.

Answer 6

attempt germanium diodes, those have a lots decrease forward activate voltage than silicone diodes, and are used for sign artwork in radio circuits, to illustrate filtering out the audio sign from a susceptible radio sign.they're even with the undeniable fact that so lots greater mushy to warmth so be careful whilst soldering.

Answer 7

Since there are many battery powered audio devices, the answer must be yes.