i studied programing assembler. i can multiply voltage and current. but i can't measure power factor.I agree with Brownout. It should be quite simple. All you need to do is have something that measures the voltage, something that measures the current flowing between the terminals, and some sort of logic system or microcontroller to do the multiplication. It should be quite easy. Have you ever done any microchip programming?
If you multiply the instantaneous short samples of voltage and current as I described then you don't need to measure the power factor. The power factor is included as part of the measurement.i studied programing assembler. i can multiply voltage and current. but i can't measure power factor.
i add DC signal to input signal adc is positive.The tolerance is determined by the accuracy of the circuits you use to measure the voltage and current.
You can use two A/D converters sampling at the same time, one for current and one for voltage. Then you read the two values into a microprocessor, multiply the two values, and store them until you have taken samples over a complete cycle of the waveform (perhaps 50-100 samples per waveform). Then you calculate the average of the values over one cycle to get the power.i add DC signal to input signal adc is positive.
it is difficult for me to sample simultaneously two signals at the same time.
what do you have algorithm solve to problem?
thanks in advance!
hello!You can use two A/D converters sampling at the same time, one for current and one for voltage. Then you read the two values into a microprocessor, multiply the two values, and store them until you have taken samples over a complete cycle of the waveform (perhaps 50-100 samples per waveform). Then you calculate the average of the values over one cycle to get the power.
Connect the ADC output to the 8051 and convert the binary by multiplying it by a factor of 400/204.hello!
i have a circuit with a 8051, adc0809 and lcd(lm016).the input of the adc is 4V.the output of the adc is (204D) equivalent to 11001100B. i want to display 4 on the lcd. i can only display 204.
can you help me?
thanks a lot.
excuse me.i use 8051 and lcd(lm032).i want to display generated characteristic. but i can't.Connect the ADC output to the 8051 and convert the binary by multiplying it by a factor of 400/204.
I sample voltage and current but the tolerance of result is large.The tolerance is determined by the accuracy of the circuits you use to measure the voltage and current.
hello!If you want true watts then you need to multiply the instantaneous current by the voltage at the same instant, do that for many samples over the compete waveform cycle, and then average all the readings. Multiplying the waveform average (RMS) volts by average watts gives volt-amps which gives true power only for a power factor of one.
Alternately you can use a dedicated energy measuring IC such as one of these.
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