FLOATING POINT ADC AND ...

[dolphin1]

HI
i have a big problem...
i want measure voltage and phase sequance with same pin(difinitly have to...)
so you knows that adc voltage is floting point and the floating point voltage include ac ripple ,,
how are you aproach this issue...
is it possible to give me a sample routine...
thank you who give me advice...

[Ttelmah]

The 'adc voltage', is not 'floating point...
It is an integer, that may 'represent' a floating point value, but as such this is down to you to decide. What the signal represents, will be down to the circuitry between the signal and the input, and the timing of the sample. For example, if you elected to synchronise the sample to the peak of the signal, it'd represent the peak voltage on the waveform. If instead you sample at a fixed interval, that is significantly faster than the waveform interval, then you will get a changing value, representing points on the cycle. If instead you sample at a much slower rate, the signal will represent the 'beat' between the incoming waveform, and the sample interval.
Noise is also down to you. You can elect (for instance), to electrically filter the signal before you sample it, or to digitally filter after sampling. A number of filter algorithms have been published here in the past.
You need to post details of the waveform amplitude, how it is connected to the processor, what you are using as the Vref, what you actually want to achieve, and what rate you intend to sample, before anyone can even begin to help you.
As has been said by another poster, 'we are not mind readers'.

Best Wishes

[SherpaDoug]

What do you mean by "phase sequance"(sequence)? Do you mean you are measuring the phase shift relative to some other signal? Or do you mean detecting zero crossings?

In either case the A/D is only going to give you an integer each time it is read. You can scale it into a voltage, though usually that is not necessary.

Tell us more about what you are trying to do.
_________________
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[Guest]

thanx to Ttelmah and sherpDoup and who read...
i want explain some thing about my idea;
use 16c712 measure AC LINE VOLTAGE(RST)
1.adjust with pot for high and low limit voltage
2.measure zero crossing the line voltage(R-S-T are 380V)
3.if sequance of line phase is correct GOTO 5
4.if sequance is not correct, GOTO 2
5.check of the high and low limit voltage
6.if voltage is in the between two limit (high-low pot limit) GOTO 8
7.else 1
8.led will be on(1)
9.GOTO 1

[Guest]

[Guest]

[quote="Anonymous"][quote="Anonymous"]thanx to Ttelmah and sherpDoup and who read...
i want explain some thing about my idea;
use 16c712 measure AC LINE VOLTAGE(RST)
1.adjust with pot for high and low limit voltage
2.measure zero crossing the line voltage(R-S-T are 380V)
3.if sequance of line phase is correct GOTO 5
4.if sequance is not correct, GOTO 2
5.check of the high and low limit voltage
6.if voltage is in the between two limit (high-low pot limit) GOTO 8
7.else 1
8.led will be on(1)
9.GOTO

http://www.edaboard.com/viewtopic.php?p=407163#407163

[Guest]

[Guest]

thanx to Ttelmah and sherpDoup and who read...

i want explain some thing about my idea;

1.adjust with pot for high and low limit voltage
2.measure zero crossing the line voltage(R-S-T are 380V)
3.if sequance of line phase is correct GOTO 5
4.if sequance is not correct, GOTO 2
5.check of the high and low limit voltage
6.if voltage is in the between two limit (high-low pot limit) GOTO 8
7.else 1
8.led will be on(1)
9.GOTO

use 16c712,4mhz vref 5v and connect to direct to mcu and measure AC LINE VOLTAGE(RST

http://www.edaboard.com/viewtopic.php?p=407163#407163[/quote]

[Guest]

thanx to Ttelmah and sherpDoup and who read...

i want explain some thing about my idea;

1.adjust with pot for high and low limit voltage
2.measure zero crossing the line voltage(R-S-T are 380V)
3.if sequance of line phase is correct GOTO 5
4.if sequance is not correct, GOTO 2
5.check of the high and low limit voltage
6.if voltage is in the between two limit (high-low pot limit) GOTO 8
7.else 1
8.led will be on(1)
9.GOTO 1

use 16c712,4mhz vref 5v and connect to direct to mcu and measure AC LINE VOLTAGE(RST

http://www.edaboard.com/viewtopic.php?p=407163#407163[/quote]

[PCM programmer]

Just to let you know, Ttelmah is in the UK he's probably asleep right now.
Sherpa Doug is on the East coast of the USA, and he's gone home from
work by now. So it doesn't do any good to keep posting over and over.