SC1200 reduced RF reception after time; needs periodic reboots?

[Brian H]

I also have not seen any schematics.
This is from disassembling the XM19A wall wart power supply from my defective SC1200.
Has the X10 power line transmitter, zero crossing detector and DC supply in it.
The 4P4C phone handset style connector. Has Common, +12 volts, Zero Crossing signal to the SC1200 and power line transmitter keying signal from the SC1200 to the wall wart.
The power line transmitter output is through a tuned isolation transformer directly coupled to the AC input. The X10 power line signals do not go through the DC power supplies transformer.

I have used a 4P4C breakout board. To key the transmitter On with out the SC1200 connected. With a resistor between the +voltage and the transmitter keying signal.

[dhouston]

This is from disassembling the XM19A wall wart power supply from my defective SC1200.
Has the X10 power line transmitter, zero crossing detector and DC supply in it.
The 4P4C phone handset style connector. Has Common, +12 volts, Zero Crossing signal to the SC1200 and power line transmitter keying signal from the SC1200 to the wall wart.
The power line transmitter output is through a tuned isolation transformer directly coupled to the AC input. The X10 power line signals do not go through the DC power supplies transformer.

Is there a stepdown transformer for the +12V power supply? EDIT: The X10 knowledge base says it's a +8V supply.

• http://kbase.x10.com/wiki/SecuriLINK_Home_Security_System

From your description it might be similar to the CM15A which has an isolated power supply or it might be similar to a TW523 which does not have an isolated power supply. EDIT: My concern is because of X10's habit of using the AC line as electronic ground. This might put the antenna ground lead at 120V relative to earth ground. 

Is the PLC output from the console a gate signal (with a free running oscillator in the XM19A) or is it the actual 120kHz burst?

[Brian H]

You are correct on the voltage. It is 8 volts not 12 volts.
The smaller ones for the MT12 and MT13 where 12 volts.
I will see if I can find more details on the circuitry.

[Brian H]

Had a chance to open the XM19A power supply for the SC1200.
Zero Crossing to the consloe. Is the output side of a 4N35 Optocoupler.
Power line transmitter enable. Is the input side of a 4N35 Optocoupler.
AC Line input. Is two pins on the primary side of a transformer. Sticking through the back. To directly connect to the AC wall outlet.
Also each line pin has a wire to the PCB. That looks like it has a MOV across them and some caps to couple the power line transmitter to the line.
Secondary is a center taped winding. With the center tap connected to common of the cable to the SC1200.
Could not get the PCB out easily. So for now. There is more data to be traced out.

[dhouston]

It appears to be similar to the CM15A AC interface circuitry. It's probably isolated.