Facing problem with two X-10 Transceivers

[snoopy5376]

I'm implementing X10 on 240V, 50Hz power line. PIC16F877A microp is used to generate 100kHz X10 signals. Proteus 7 is used to simulate my result.

This is my transceiver circuit:


The Tuned and Untuned Amplifiers are shown below:


This is the output i got when the transceiver send and receive on its own.

Yellow - 240V power line, Blue - 100kHz X10 signal from XOUT, Red - Received Signal at XIN

I face problem when i try to send and receive using 2 different transceiver where TranscA is to send and TranscB is to receive. I connect both of them to the 240V power line as shown below:

TranscA


TranscB


But what i got is as shown:

Yellow - 240V power line, Blue - 100kHz signal generated by TranscA, Green - Signal received by TranscB

Is this the correct way to connect both the transceiver in simulation? Where have i gone wrong? Will it be the filter circuits, or the pwm programming, or which part? Thanks in advance for any help

 

[(*steve*)]

The first issue is that when a transmitter is sending to itself, the output of the transmitter is connected to the input of the receiver.

This means it gets a much larger signal.

Have you looked at the 240V line? Does any signal appear on it?

I would connect the transmitter and receiver independently to the 240V.

 

[snoopy5376]

This is a transceiver (transmitter and receiver on a same board). The connections were according to microchip AN236 http://ww1.microchip.com/downloads/en/appnotes/00236a.pdf. There is no problem for a transceiver to send and receive by its own.

Now i would like to try to send and receive using two different transceivers (A and B). In real world, these two transceiver should be connected independently to the powerline. However, i would like to try on simulation first. therefore, i connect them through TRANSCB as shown in the attachments above in simulation.

As for the 240V powerline, there are glitches on the 240V powerline whenever the X10 signals exist. so i assume that the X10 signal is successfully transmitted to the 240V powerline.


Am i correct?

 

[(*steve*)]

I see nowhere that it suggests that a transmitter and a receiver can share the same coupling to the mains. Perhaps you can point it out?

 

[(*steve*)]

The 50 ohm resistor on the transmitter side will effectively be attenuating the input signal to next to nothing. Maybe you could try using a line driver with a tristate output and placing it in a high impedance state when you're not transmitting?

 

[snoopy5376]

From AN236 Figure 4 and Figure 5 show that the transmitter and receiver are using the same decoupling capacitor. Besides, i am following Figure C-4 and C-5 at the appendix part. The only difference is the filter part.

 

[(*steve*)]

Why aren't you using their filter design?

It may offer a lot more gain than yours.

try disconnecting the transmitter part of your interface and see if it works. Then try increasing the gain.

Is the mains you're injecting this signal onto isolated with a transformer?