There used to be a circuit diagram on the web for the hardware of a UPB interface to a microcontroller, consisting of a handful of coils and capacitors going into a microcontroller. Anyone know where to find it? Let me explain why ...
I have a smallish setup of UPS switches and outlets at home, about 25 devices, and it keeps working near perfectly; I've even expanded it in the last few years a little bit (mostly by scrounging in my parts bin, and finding used modules on eBay. Except for one recent annoying problem: I just had a SimplyAutomated US22-40 switch fail on me. The problem here is that those are de-facto irreplaceable: None are for sale on eBay or other auction sites, and I'm out of spares. And the location it's installed in is somewhat cramped (2-gang box with two US22-40 switches), so simply replacing them with single-output switches (SAI or PCS) is not easy. For now, the problem is handled by moving another switch into it, and temporarily abandoning one output (no need for cooling fans in this weather).
The symptoms of the failure are interesting. The switch itself works great locally: all 8 microswitches work, the two loads can be controlled and even dimmed, the LEDs work, it survives power outages, and has not lost its programming. Pressing any button 5 times quickly puts it into programming mode (blinking LED). It can transmit UPB commands into the power line just fine. The only problem is: it can not receive any UPB packets (which also means it is invisible to UPStart). There is no smoked components, everything smells good, there is no visible damage to the board. This failure mode makes me think that the failure is very likely one of the capacitors that receives UPB pulses. If that's not it, then it could be the actual input pin on the PIC chip (which would be hard to fix). It could theoretically also be in a resistor or inductor, but those hardly ever fail. The large capacitors that connect the PIC to the power line interface are easy to see on the board. Since I know a bit about electronics, I'm toying with the idea of just identifying the failed capacitor, ordering a replacement from Digikey (SAI seems to use pretty standard components).
If I had a circuit diagram, that would all be much easier, since I could go directly to the components in the UPB pulse receive path, and not first figure out what capacitor does what. The switch is very densely built (with some components buried underneath others), and having to figure it all out for scratch will be many extra hours of work.
Alternatively, does the assembled wisdom here know exactly what to look for? For example: "Look at the 470nF 250V capacitor that goes from neutral to a resistor network on the board, it likes to die early".
I have a smallish setup of UPS switches and outlets at home, about 25 devices, and it keeps working near perfectly; I've even expanded it in the last few years a little bit (mostly by scrounging in my parts bin, and finding used modules on eBay. Except for one recent annoying problem: I just had a SimplyAutomated US22-40 switch fail on me. The problem here is that those are de-facto irreplaceable: None are for sale on eBay or other auction sites, and I'm out of spares. And the location it's installed in is somewhat cramped (2-gang box with two US22-40 switches), so simply replacing them with single-output switches (SAI or PCS) is not easy. For now, the problem is handled by moving another switch into it, and temporarily abandoning one output (no need for cooling fans in this weather).
The symptoms of the failure are interesting. The switch itself works great locally: all 8 microswitches work, the two loads can be controlled and even dimmed, the LEDs work, it survives power outages, and has not lost its programming. Pressing any button 5 times quickly puts it into programming mode (blinking LED). It can transmit UPB commands into the power line just fine. The only problem is: it can not receive any UPB packets (which also means it is invisible to UPStart). There is no smoked components, everything smells good, there is no visible damage to the board. This failure mode makes me think that the failure is very likely one of the capacitors that receives UPB pulses. If that's not it, then it could be the actual input pin on the PIC chip (which would be hard to fix). It could theoretically also be in a resistor or inductor, but those hardly ever fail. The large capacitors that connect the PIC to the power line interface are easy to see on the board. Since I know a bit about electronics, I'm toying with the idea of just identifying the failed capacitor, ordering a replacement from Digikey (SAI seems to use pretty standard components).
If I had a circuit diagram, that would all be much easier, since I could go directly to the components in the UPB pulse receive path, and not first figure out what capacitor does what. The switch is very densely built (with some components buried underneath others), and having to figure it all out for scratch will be many extra hours of work.
Alternatively, does the assembled wisdom here know exactly what to look for? For example: "Look at the 470nF 250V capacitor that goes from neutral to a resistor network on the board, it likes to die early".
