Using a signal generator to power a magnetic coil and Repeat a Damped Sine Wave.

Projects General Guidance
1

I want to control a signal generator to control a magnetic coil (copper electromagnet). I want to use a signal which is a damped Sine Wave. This is to generate a Pulsed Electromagnetic Field.

The general equation for an exponentially damped sinusoid may be represented as:
Amplitude y(t) = InitialAmplitude* e^(-DecayConstantLambda*t) cos(Freqt + phase angle)

So, first a simple question: What hardware would I need to do this? What Software would allow me to control the signal with this formula?

My next problem will controlling the Amperage/Voltage of my electromagnet.

Thanks.
Ed

2

Signal generators are usually not designed to provide significant power to any load. Depending on the frequencies involved, coil characteristics and required coil power, you will probably need an amplifier. Software is relevant only if the signal generator you choose can be controlled by software.

For specific advice, please provide project details.

3

The Arduino doesn't have a DAC (no true-analog output) so it's probably of no use. It can put-out a digital pulse (depending on the pulse width & frequency) but it can't put-out a sine wave.

You can use a computer, soundcard, and software to generate the signal. That's assuming the signal isn't ultrasonic or higher. [u]Audacity[/u] has a programming language called Nyquist which is supposed to be fairly simple. GoldWave has an "Expression Evaluator" which might work, or you could use MATLAB, or something similar.

Or, if you are a programmer you could write a program from scratch in the programming language of your choice.

Of course, you do have to understand the basics of digital audio. Continuous functions/equations won't work with discrete-sampled data.

My next problem will controlling the Amperage/Voltage of my electromagnet.

Now, that's the "big problem". What are the voltage & amperage requirements? You'll probably need something custom designed. If you are "lucky" an audio power amplifier might work (again assuming audio frequencies). But most likely, you'll need more voltage and/or more current than you can get from an audio amplifier.