I need a power supply with the frequency range from several Hzs to
1MHz, but no such power supply is available, I'm thinking to use the
broad frequncy range of a power signal generator (e.g. 10Hz~1MHz), to
drive a Helmholtz Coil, to excite a high frequency magnetic field.
Is it possible ? Anbody know how to modify it to realize that? Or is
it impossible ?
Thanks
Another winner from http:/ /groups.google.com
What voltage, power, efficiency, and how much distortion can you
tolerate? You might want to know the resonant frequency of the coils
you want to drive too, since that would affect the design if they are
close or below 1 MHZ.
What you want already exists, they are called linear amplifiers you
put one on the output of the signal generator to bring the power up.
Some audio amplifiers can reach beyond 1 MHZ - they usually
incorporate some form of "frequency roll off" to limit the frequency
response to audio.
10 HZ is no problem to a DC coupled amp.
The amp and output stage parts may have no problem reaching 1 MHZ but
the layout of the circuit boards is often the limiting factor - at
higher frequencies it is easy to get capacitive feedback from output
to input and the circuit is unstable and oscillates. Built with an
eye towards maximizing bandwidth - shielding and/or neutralizing and
there's no reason it shouldn't work.
Human hearing doesn't go beyond 20 KHZ and to keep the amp compact and
cost down, there's no reason to build audio amps to go beyond 100 KHZ
or so. Audio amps are used to provide the gradient fields for MRI
machines.
