[time-nuts] OT: AC voltage standard

[Bruce Griffiths]

Joe McElvenney wrote:
> Hi,
>
> Excuse the topic but is does push the same buttons as it were.
> After calibrating my old HP54502A 6-bit digitizing scope I'm left
> with an error I can't quite believe and so am trying to determine
> which of my instruments is telling me lies.
>
> Anyone know of a simple way of producing an AC voltage standard
> suitable for general workshop use without reference to another
> one? About one percent would be good enough, wave shape and
> frequency accuracy not important (wash my mouth out). I have a
> Weston Cell for DC voltage calibration, a Rb one for frequency but
> nothing for AC volts. Perhaps there is a chip out there that
> clocks between accurate limits that I could use as a source?
>
>
> Thanks - Joe
>
>   
Joe

NIST (Then NBS) started with thermal voltage converters as AC to DC
transfer standards and later built AC standards using DACs to produce
computable AC waveforms.

You could always use a DAC to synthesize an AC waveform, for low
frequencies (< 50kHz) at least.
Or just roll you own with a CMOS shift register and a bunch of resistors.

For higher frequencies, if one keeps the distortion down a pair of
matched diodes can be used in an AGC or other leveling loop to regulate
the output of an oscillator.

Fluke used to produce an AC voltage standard.

Bruce