Comment summary #22
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Comment 211 ... 220
| date | article | author | comment |
| 23 jul 2016 16:03:09 | Arduino wattmeter | BSEE TUP Manila | Hello, any substitute for the shunt resistor? it's not available here in Philippines. Thanks in advance :) |
| 22 jul 2016 07:29:47 | Arduino wattmeter | fadhelaa | deare Freddy thanks for your answer ^_^ acctually , i have a project of smart meter and balance 3 phase unbalanced loads using an arduino could u help please |
| 21 jul 2016 22:57:43 | Arduino wattmeter | Freddy | You cannot extend this Wattmeter to a three phase version due to lack of insulation between the three lines. And because there is no room to extend the software and the hardware is not sufficient. The only choise is to use three fully insulated from each other seperate wattmeters. |
| 21 jul 2016 22:51:44 | New wattmeter project | Freddy | Thanks for your input. I'll definitely look at your suggested controller when I continue this project. I'm currently recovering from an illness and unfortunately my partner in this project quit a while ago because he become too busy with his job. I need to find another partner because I will not bear this project on my own. |
| 20 jul 2016 19:26:33 | New wattmeter project | Brian | Hi Freddy. This project looks promising, although I question the use of two AD7766 parts (at least as used in the current test fixture photo). without knowning your design goals I can't really say if these are what you need or not, or whether something better suited for the task might be better for you. Those 2 ADC's are going to be a major cost in the BOM, at over $20 for both, probably. You might want to consider the TI MSP430i20xx series, these are mixed-mode processors with up to 4 integrated 24-bit delta-sigma ADC's. The entire processor with 4 ADC's and on-chip reference is just $4.00 in qty 1, and will be much cheaper in higher quanties for your project. Whether or not the ADC's will fit your specification requirements is up to you to decide. But if I was designing a wattmeter today, I'd use that chip, and it can easily get up to 0.1% accuracy after calibration. There is an on-chip thermistor designed for use with software temperature compensation. Great work in your previous project, and I look forward to this one too. |
| 20 jul 2016 14:16:51 | Arduino wattmeter | fadhelaa | Hello ^_^,I would like to thank you for these amazing info that you explained I have a question please that if i can use these wettmeter in 3 phase circits ??? and to balance loads ????? |
| 23 jun 2016 14:40:26 | Multimeters - measurement deviation | Clyde Coombs | This is an important sight to me as an electronic technician. Thank you |
| 22 jun 2016 15:13:29 | Magnetic permeability | Kevin_Pilg | Hello, I would like to present my problem with the measurement. I have got a ferrit core ( two U-Shape glued togeather) he task is to get the µr of the material. The absolute values are NOT of major interest, more the behavior over the frequency spectrum. I took measurments and got good results, except that the decline of the µr comes about 10kHZ, where the manufacture says it should decline at 1Mhz (so a factor of 100 in the frequency ) I have got diagrams for illustration if needed. I don't understand why there is the factor of 100 in the results . ( so again the values for 1Mhz are at 10kHz roughly ) Thank you so much for help |
| 18 jun 2016 20:43:39 | Fast Lux meter | Manfred | Hi Freddy, i´ve completed my Fast Lux meter and it works great. Because I hate the 9V cells, I use two AA eneloop cells and a MT3608 step up converter for the supply. After some filtering it has -3V and + 13.5V. The output works linear up to 300kHz exactly as proposed (even with full 12V AC signal). Thanks to the slew rate of 17V/us of the OpAmp you have selected. I wonder, how you could predict the frequency response so exactly. Many thanks for your great idea and your professional circuit design! |
| 14 jun 2016 16:48:23 | Arduino wattmeter | Jesso | Thank you for your answer. I find it a little bit hard to understand your methods so I tried to use the LCD Library since I have been working with this library to manage the display on the LCD. Regards, Jesso |