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Re: X-10 Broadcast Storm Detector



That's NOT a transformer based supply - no power supply whether switch mode
or linear is likely to pass the X-10 signal. It's merely a 120V:12V AC
transformer. There are internal diodes and capacitors that convert it to
±18V DC for the dual-supply opamp and to +5V DC for the other chips used by
the ESM1. John Galvin published a schematic of the ESM1 - search this group
on his name and ESM1. Or you can see it on my web page at
http://davehouston.net/ESM1-TEST.htm


"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

>I've started my project and the first thing I decided to do was to cut the
>cord between the power supply and the meter head of the ESM1 and to install
>a jack on the meter head power leads so that I could examine the performance
>of various 12VDC 500MA adapters that I have around the house.  I wanted to
>see whether I really need to acquire multiple units of exactly the same
>power supply to get equivalent readings from each of the branch circuits.
>It seems that transformer-based power supplies are getting harder to find!
>I assume that a switched power supply wouldn't pass the X-10 signal along
>the way a transformer-based supply would.  This will also enable me to test
>various lengths and gauges of wire to see how cable length affects the X-10
>signal.
>
>I've also decided to monitor the LED bargraph as well as the X-10 and PWR
>LEDS on the unit.  My reasoning was simple.  As long as I was monitoring the
>existence of X-10 traffic, I might as well add a few more photodetectors and
>monitor the bargraph at three points to give me readouts of high, low and
>medium signals.  Since the cradle's interface panel will prevent me from
>aiming a camera at the meter and sending the signal to a remote monitor,
>optically coupling the cradle to the LED bargraph should accomplish much the
>same thing and give me an output I can read remotely via something like the
>Ocelot.
>
>I've been reading up on the 555 chip and they're incredibly powerful little
>devices with lots of capabilities.  I'm putting together an order for
>phototransistors, some GP circuit boards for IC devices and a few different
>versions of the 555 chip and hopefully will have time to design the basic
>circuitry in a few weeks.  Ironically, in putting together the basic 555
>circuit it's a little easier to see where ladder logic came from and how it
>works!  (-:



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