[Message Prev][Message Next][Thread Prev][Thread Next][Message Index][Thread Index]

Re: Justify Upgrade from X-10 to Z-Wave?



"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote in message
news:YtadnSjezeK3yffVnZ2dnUVZ_sHinZ2d@xxxxxxxxxx
>
> I hooked up the Monterey PLSA behind an AF120 15A filter and got some
> interesting readings.  The WGL received an RF command and put it through a
> TW523 onto the house wiring.  The Monterey showed normal commands being
> received (at .15 volts, even behind the filter!) with one exception:  The
> display showed them all in lower case, which means it only saw the second,
> repeated half of the command.  That makes perfect sense.  The II is
> stronger
> than the original XTB and the XTB/TW523 combo was on another circuit.
> Only
> the repeated signal could punch through the filter, as would be expected.
>
> The next test is to see whether the WGL's TW-523 alone gives the same
> readings.  If it's higher without the XTB, then there's cancellation going
> on.  If it's higher *with* the XTB then the two signals are combining.
> IIRC, the IIR alone can't punch through the AF120.  The fact that is does
> so
> when it's amplifying an already boosted signal from the XTB seems to
> indicate that the end voltage of an XTB that's repeated by the XTB-IIR is
> considerably higher than either unit alone.
>
> I tried doing some "signal dissect" runs where the Monterey looks at each
> of
> the 22 cycles and records 0's and 1's and their voltage during each cycle
> and that gave me information that seems to imply cancellation is
> occurring.
>
> Cycle
> 01        1    .42      1  .43
> 02        1    .39      0  03m
> 03        0    02m    1   .42
> 04        1    .38      0   03m
> 05        1    .38      0   02m
> 06        0    02m    1    .41
> 07        0    02m    1    .41
> 08        0    02m    1    .41
> 09        1    .37      0    03m
> 10        1    .37      0    03m
> 11        1    .38      0    02m
> 12        1    .25      1    .24
> 13        1    .22      0    03m
> 14        0    03m    1    .22
> 15        1    .21      0    03m
> 16        1    .20      0    03m
> 17        0    03m    1    .20
> 18        0    02m    1    .19
> 19        0    02m    1    .19
> 20        1    .18      0    03m
> 21        1    .18      0    02m
> 22        1    .17      0    03m
>
> Now that I've transcribed that lengthy list two things seem to jump out.
> First, the noise level is very low, probably the result of the Monterey
> sitting behind the AF120 filter.  The second is that the repeated frame is
> seems to be actually weaker than the first copy of the X-10 command.
>
> Obviously I need to run more tests with both the XTB and the XTB-IIR but
> it
> looks like we're seeing some fade in the voltage as the command
> progresses.
> Looks fairly linear, too.
>

Since the XTB-IIR power supply is not regulated, it will droop as the
transmitter is pulling current from the 4700uF energy storage capacitor.
(The TW523 has 470uF.)

Measurements here show about 5% droop over a single transmission.  (You can
see that in the Hometoys workbench photo.)  The droop does depend on how
nasty a load is being driven.  More current will be pulled from the supply
when driving a heavy load, which will cause more droop.  Sustained
transmission into a 4.8 ohm resistive load will result in about 30% droop
(and a very hot load resistor.)  The version 1.2 board supports a full-wave
bridge power supply, which has slightly better regulation.  The total energy
delivered is about the same, but there is less change in burst amplitude
over the transmission.  That was first incorporated into the 3-phase unit,
but it will be ported over to 2-phase unit when the new transformers arrive.

While I?m not quite sure how the measurements were made, I suspect that you
had a XTB driving the same phase that the Monterey was monitoring.  I would
expect that to be a stronger signal than when the XTB-IIR is driving both
phases, especially if the opposite phase contains more ?signal suckers?.  In
any case, that is a pretty respectable signal being punched through that
filter.

Jeff




comp.home.automation Main Index | comp.home.automation Thread Index | comp.home.automation Home | Archives Home