I suppose one just needs to check with a scope to see what's coming out. The
ferroresonant Solas that I've seen produce clipped sine waves.
73
-Jim
NU0C
On Wed, 28 Aug 2013 19:35:50 -0700, Richard Knoppow wrote:
>
>----- Original Message -----
>From: "Jim Shorney" <jshorney@inebraska.com>
>To: <Amateur-repairs@yahoogroups.com>
>Sent: Wednesday, August 28, 2013 6:33 PM
>Subject: Re: [Amateur-repairs] In search of the basic test
>equipment for workbench.
>
>
>
>Solas don't produce a pure sine wave. This will tend to
>throw some voltage
>readings off.
>
>73
>
>-Jim
>NU0C
>
>
> Modern regulating transformers put out quite pure sine
>waves. Some very early Sola types did not. I doubt if the
>impurity would cause any significant measurement error
>especially after being turned to DC. The error in a meter
>depends on type of AC to DC converter it uses. A single
>diode, as found in RF meters, is RMS reading for very low
>levels, i.e. below about 1.5 volts, and becomes a peak
>reader at higher voltages. In the range where it is peak
>reading the error can be as large as the percentage of
>harmonics in the signal. Most audio meters and others like
>the Hewlett-Packard 400 series, use a full-wave bridge.
>These respond to the average of the waveform. The error from
>the RMS calibration can be several percent but is much
>smaller than for a peak reading meter. Of course, a
>true-RMS meter is immune to these errors. Note that both
>single diode and bridge type meters are calibrated in the
>RMS value of a sine wave which accounts for the error since
>they do not really read RMS.
> Non-electronic meters such as analogue VOM's are bridge
>type which respond to the average but are calibrated as RMS.
>
>
>--
>Richard Knoppow
>Los Angeles
>WB6KBL
>dickburk@ix.netcom.com
>
>
>
--
The universe we're in will reach absolute zero in three hours. Safe is relative. - Idris, "The Doctor's Wife"
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