Variable frequency AC supply
Variable frequency AC supply
(OP)
Doing some expirements on low inductive load and I need a variable frequency AC supply. 0-200 kHz, 30 W. Reasonably clean sine wave.
What would be a cheap way to do this?
Have function generator.
Thanks in advance
What would be a cheap way to do this?
Have function generator.
Thanks in advance





RE: Variable frequency AC supply
Benta.
RE: Variable frequency AC supply
RE: Variable frequency AC supply
This type of testing can generate some very low and reactive load impedances which can easily let the smoke out of many typical audio amplifiers.
Either a single monster amplifier, or several amplifiers, but make sure there is some additional series resistance placed between amplifier and load.
A resistive tee attenuator network would be even better as it also offers some protection from high reflected voltages.
However you do it, there is likely be a great deal more heat and power involved than you might expect, to reliably generate a measly thirty watts into a "difficult" load.
RE: Variable frequency AC supply
i am afraid you may be crediting mo with more knowledge of electrical engineering than i have.
any ready-made products out there?
RE: Variable frequency AC supply
Not that I am aware of.
The problem is this type of testing is fairly obscure, and so the test equipment needs to be custom made to suit the specific application.
A lot of this type of analysis is done these days by computer simulation, often using "Spice".
But that can only take you so far.
Magnetics can often exhibit strange non linear characteristics that are best measured directly under real operating conditions.
RE: Variable frequency AC supply
One company name is Amplifier Research. I'm not sure if they offer LF amps. They do offer very wide frequency range RF amplifiers. We have a 75 watt one where I work.
The "0" Hz in your frequency requirement is something to consider carefully. Make sure you require exactly what you're asking for at the low end of the stated bandwidth.
RE: Variable frequency AC supply
RE: Variable frequency AC supply
I use transformer if I need to do high voltage (grid simulation with 'funny' waveforms) or high current at different frequencies for impedance testing and primary injection tests.
The 400+ watts are awesome and I can't live without it.
Gunnar Englund
www.gke.org
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