Re: Function Generator Output Impedance

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "Barton B. Anderson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>
> 
> Hi All,
> 
> Question:
> While looking for low output impedance generators, I keep running across 50
> ohms which appears to be typical. Are there lower output impedance
> generators? Are there methods to reduce a typical 50ohm output impedance
> generator down to near zero ohms?
> 
> Thanks,
> Bart

	There are power opamps (and maybe even integrated audio amplifiers)
available which might work, depending on what frequency, voltage, and
current you need.  Stepdown tranformers are very useful too.  For TC
resonant frequency and Q measurements I use an audio oscillator with
fairly high impedance, a stepdown transformer, and finally a shunt
resistor across the secondary to more or less "define the impedance". 
Of course, for non-sinusoidal waveforms the transformer may cause too
much distortion.

Ed