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If you need help on Microchip's smart metering products, ask Mike! Mike Ballard is the SR. Manager for Home Appliance Solutions Group and Smart Energy Solutions Group for Microchip Technology Inc. Mike has 15 years of experience in the industry with technologies such as microcontrollers and analog, and has an extensive knowledge of Microchip's products serving the Smart Metering market. Click here to ask Mike a question!

0 KennyMillar over 14 years ago

Hi Mike,

I'm a big fan of Microchip products, and have used several recently in various designs for various clients.
One project I'm working on is a rack mounted 6 Way power switch - basically one mains IN, and 6 individually wicthable mains outputs.
Each output has to be monitored and its power usage logged. The current draw from each output can vary anywhere from a few watts per channel up to 3000 Watts, yet the monitor needs to be reasonably accurate.

I've looked at using current sense transformers coupled to ADCs - but it's tricky because of the requirement for accurate monitoring anywhere from 3 watts to 3000 watts.

What products do Microchip offer which might be useful for this device?
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0 Former Member over 14 years ago in reply to KennyMillar

Hi Kenny, thank you for your question, our expert will be getting back to you shortly!
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0 enrico.migchels over 14 years ago in reply to KennyMillar

Hi Kenny,

Mybe it is wise to calibrate your system to compensate for offset, drift and temperature effects. As the outputs are switchable you know when there is 0 power drawn. The ADC value is your offset error. It is always difficult to make a accurate wattmeter with such a large range. For the lower range you might want to use the kWh approach. That is; measure the power for a certain time (integration) and divide this over time. This gives a more stable power reading.

Best regards, Enrico
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0 Former Member over 14 years ago in reply to KennyMillar

The MCP3901A0-I/SS.MCP3901A0-I/SS. will likely be the best answer here. Effectively this design is looking for a 1000:1 dynamic range, but the accuracy needed over this range will determine the overall accuracy required by the analog front end. The MCP3901A0-I/SS.MCP3901A0-I/SS. should be able to handle this type of dynamic range with a measurement error of 0.1% typical. The MCP3906A could also handle this and perform the active power calculation as well.

Mike Ballard
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0 KennyMillar over 14 years ago in reply to Former Member

Mike,

Thanks for the reply - I will check out those parts.

-Kenny
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0 Former Member over 14 years ago in reply to Former Member

Hi Mike,
It's MCP3901A0-I/SS.MCP3901A0-I/SS. same AFE which are in MCP new MCU PIC18F87J72?
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0 arjv over 7 years ago

Hi sir,
we are doing a project on PIC18F87J72 based single phase energy meter (PIC18F87J72 1-Phase Meter Reference Design). In the BoM available along with the project says that the lcd used is, description: LCD 7 Digits 28 pins, manufacturer part no: LCD_INDIA. i found this detail in the meter reference design revision 3. screen shot added below. but the problem is i cannot find the type of lcd that has been used in that design. please help me to find where i can get that kind of lcd display. please reply me ASAP.

thanks n regards,
ARUN RAJ
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