Ldanielrosa Posted January 31, 2004 Report Share Posted January 31, 2004 Is there any serious problem with signal lines being close to power lines as long as the frequencies are the same and they are synchronized?FWIW, I was thinking about using 15VAC (square wave, two phase, moderate frequency) to power some remote gadgets with a piece of telephone line. Quote Link to comment Share on other sites More sharing options...
MP Posted January 31, 2004 Report Share Posted January 31, 2004 Actually, there are network devices that use your power lines of the house to communicate on. The AC is filtered out at the other end. Another example is the ABS brake system on most cars. The sensor sends an AC signal to let the processor know the wheel is moving and a DC signal is also generated to tell the processor that the sensor is functioning. This is so that the processor knows the wheel is locked and not a broken sensor wire when the car is moving and there is no AC signal. It is all a matter of filtering out what you do not want at the other end.MP Quote Link to comment Share on other sites More sharing options...
Staigen Posted January 31, 2004 Report Share Posted January 31, 2004 Hi there. This question actually is confusing me a little, are you saying the frequenciy in the signal line is the same as the frequency in the power line and are syncronized? Or do you mean that there is a DC power line and a signal line running close to each other?//Staigen Quote Link to comment Share on other sites More sharing options...
Ldanielrosa Posted January 31, 2004 Author Report Share Posted January 31, 2004 MP: I understand that filtering can remove a lot of interference. I'm hoping to make that unnecessary by aligning the bits (timewise) with the center of the flattened peak of the power (when the ringing is the least).Staigen: Yes to the first question. At the moment this is conjecture. Since the devices would be remotely located, trying to supply 5VDC to all of them from a central supply is unrealistic. Since I may want to use some analog components, a split supply may be necessary. Raising the frequency allows for smaller capacitors. Quote Link to comment Share on other sites More sharing options...
Staigen Posted January 31, 2004 Report Share Posted January 31, 2004 Than i dont think its going to be a big problem, but a little moore info about the whole thing would help. A brief schematic for example.//Staigen Quote Link to comment Share on other sites More sharing options...
MP Posted January 31, 2004 Report Share Posted January 31, 2004 Yes, a schematic would be very helpful. I think that you are still going to have a problem with inductance characteristics. Filtering is going to be essential to make it work. MP Quote Link to comment Share on other sites More sharing options...
russlk Posted February 8, 2004 Report Share Posted February 8, 2004 The advantage of AC power is that you can transmit at high voltage and low current, for low loss, and transform back to low voltage and high current at the load. But, 15 VAC is not high enough to be efficient, why not send the power as DC? The signal coming back could be on an AC carrier, or if it is logic could be sent directly with Manchester coding. Quote Link to comment Share on other sites More sharing options...
Ldanielrosa Posted February 8, 2004 Author Report Share Posted February 8, 2004 Disclaimer: This is somewhere between conjecture and fantasy, so a schematic of my ideas is a bit difficult to produce.That much taken care of...russlk: I'm constrained by a few realities. The wire size is about 22ga, and I'd like to locate some gadgets 50m or more from the power supply. Some of them may have devices that want a higher voltage than 5V, or a split supply. If these are _ever_ subject to inspection, I want to keep _all_voltages low enough to be exempt from permits/regulations. I'd also like to load the power supply evenly regardless of the device in question.all: The last point gets a bit sticky. To keep true with this objective, I may have to run uCs on a Quote Link to comment Share on other sites More sharing options...
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