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infinityis last won the day on February 26 2012

infinityis had the most liked content!

About infinityis

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  1. I've completed what should be the final design iteration for the ProtoPowerSwitch BoosterPack. This version of the board provides more simplicity, flexibility, and ease of use compared to the previous versions. There is only one switching element per board, and (as before) it can be a relay, TRIAC, or SCR. -When populated with a relay, the relay coil power can be provided by the transformerless power supply or by the 5V on the Launchpad. -The microcontroller can be powered from the AC mains connection via transformerless supply or from USB (selectable with jumpers), making it e
  2. I see one definite problem: the 815 optocoupler in position U1 is installed backwards; you'll need to remove it and rotate it 180 degrees. The alignment dot on the silkscreen art is fairly small, so I'll make it larger on the next revision of the board. For the SCR and TRIAC, the three position terminal block is unnecessary, you only need two. This is definitely not a problem though. I used some three position terminals on mine because I ran out of the two position terminals. I only see one MOV behind the relay (is there a second one?), which may be perfectly fine. If you only plan to
  3. The gate resistor is indeed a standard resistor; it is only called a gate resistor because of how it is used in the circuit, connected to the gate of the TRIAC or SCR. Good catch on R3, I've corrected it above to be a 180ohm resistor part number. In the schematic, yes, SW2 is a TRIAC and SW3 is a SCR. R1 for the relay section is either a 330ohm resistor for an opto-driven relay coil or a 680ohm resistor for a transistor-driven relay coil (I've updated the BOM above to reflect that as well). In the schematic, SW1 is a relay that is driven by an optocoupler, whereas SW4 is a relay drive
  4. (sorry for the delay in responding; the kids were sick last week and there was quite a bit to respond to!) Assuming you avoid the transformerless AC power supply capability of the board (which I recommend to keep things safer while still in development, and there would need to be a power budget analysis to see if it is feasible)... You should not need to disconnect the USB from the computer, because all the high voltage traces/planes are optoisolated from the microcontroller (and thus from any USB connected devices as well). I mention that because I occasionally found it useful to keep i
  5. Presently the schematic uses P1.0 as input for the zero volt crossing signal (if you wanting to use a TRIAC), and P1.4, P1.5, P1.6, and P1.7 are used to control each switch. Given that the Ethernet Boosterpack schematic uses P1.5, P1.6 and P1.7, that will only leave P1.4 and P1.0 unless an alternative pin mapping is used. Knowing this in advance, Aside from the LEDs (which can just remain unpopulated), the only other place those pins go are to through-hole resistors to drive the optos. Since this is just a prototype I can just wire the resistors directly to other available pins instead.
  6. Hey Matt/Nytblade, I'm definitely still working on these boards, about to send out another order for newer boards with the changes I referred to previously to support the use of MOSFETs. If those work out, I plan to buy in larger quantities and finally get something up on the 43oh store. Believe it or not, I was already actually considering sending you something to work with. I've been keeping up with your Youtube videos and I when I saw the one where you controlled a light with a generic dual relay board, I thought "he sure could use what I'm working on....I need to hurry up and make it
  7. I've made some more changes to the board, implementing everything indicated in the previous post, from including mounting holes to providing compatibility with the 40-pin launchpads. I've also cleaned up a lot of the code and set it up as relatively simple a library of functions to help manage things like the phase angle firing of TRIACs/SCRs. The picture below shows several configurations of the board which can be built from the current board design: The attached PDF provides details on the construction of each. It shows a range of options from developer-friendly versions that are U
  8. cubeberg, I've also been looking at using 5V from the Launchpad USB connection, and I think I've found a reasonably good way to do that and simultaneously support the 40 pin Launchpads (C2000, Stellaris). If you have room, include pins for a 40 pin launchpad. One of the "new" pins (not found on a 20 pin LP) is 5V directly from the USB, at least for the C2000 Launchpad (pin 1 of J5). If someone wants to interface the boosterpack to a 40 pin launchpad, the 5V connection is made automatically, and if someone want to interface the boosterpack to a 20 pin launchpad (like the MSP430), TI was gra
  9. I've had the parts soldered in for awhile now, but it's taken a bit to get up to speed with the code. To do phase angle-controlled firing of the TRIAC/SCR meant learning how to use the TimerA and all, so with that done, I was able to test the hardware today. I've got it all working now, but the board will need one more revision to work out a few small issues, including: -Swap pins on the LDO. I changed to a TO92 for this board and managed to mix up two of the pins. -Swap pins for the TRIAC/SCR. I had MT1 and MT2 mixed up for the TRIAC and anode/cathode mixed up for the SCR, such that it
  10. Judging by their C2000 LED boosterpack, even TI doesn't seem to follow their proposed standard sizing for Boosterpacks.
  11. I think having a standard is nice, but what TI drew up seems a bit constraining in the wrong places. For example: -They don't specify any constraint on thickness of a boosterpack. Perhaps there isn't one, but I know that for the AC-powered AC-relay/SCR/TRIAC controller I'm making, you likely won't be able to stack anything on top because of the component heights. -Why would they bother to limit the maximum height dependent on whether or not the 3 pin GND/GND/VCC header J3 is used? This seems arbitrary, because if I really wanted to make use of the space, but I don't really need the J3
  12. Thanks for the response. About the Vref, turns out I was looking at a datasheet for one of the low-end MSP430s that only did the divider approach, but I do see the selectable reference you mention in some of the more capable ones. Good point on the MCP3208; I mostly looked at the datasheet for the MCP3903 and didn't realize the 3208 wasn't concurrent as well. Looks good!
  13. The new boards are in! Hopefully I can find some time to solder it up soon and verify the functionality. They were ordered from Iteadstudio, which was actually a better deal than Seeedstudio for this size board, plus it included 100% etest instead of 50%, and they threw in an extra board when they shipped them (final qty: 11). The build quality looks quite nice. The only problem I've seen so far is that I accidentally made a few of my vias too large so they didn't tent properly. Thus, one via doesn't meet HV clearance requirements so I may have to conformal coat that via. In the meantime
  14. @oPossum Both approaches look reasonable. Some things I am wondering about: In the first circuit, is there a reason you used the Vref from the MSP430? It is a voltage divider internally and doesn't provide any additional regulation compared to Vcc, so you could free up that pin and use a separate resistor divider (if you want). I'm also not sure why you'd need to buffer the reference with IC1A, since neither the ADC nor the input terminal of the op amp should draw much current from it, and even if they did, you're set up to cancel out any resulting biases with your CH0 measurement.
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