Zero-crossing refers to detecting the point at which a sine wave reaches the zero point of magnitude. In AC circuits it corresponds to the point at which no voltage is present so switching at that point reduces interference.
Questions tagged [zero-crossing]
148 questions
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Zero crossing detector: do I really need the 7W resistor?
I am trying to provide zero crossing detection to my controller. Using the schematic below, I managed to generate square wave signal, representing positive v/s negative half-period. The problem is that the resistor needs to be quite large :
CTR >…
Vorac
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4 answers
zero cross detector missing zero cross
I'm trying to make a zero cross detector. I used the schematic below as a reference.(schematic from http://microcontrollerslab.com/zero-crossing-detector-circuit-using-pic-microcontroller/)
However if I hook up my scope then I get the following…
ChThy
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4
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2 answers
Art of Electronics zero-crossing circuit question
I'm trying to make sure I understand how this circuit works fairly well before I read on. Here is the diagram:
Here are some of the things I am thinking about this circuit:
Because input goes to the inverting input, positive inputs result in…
Fixer69
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2 answers
Why is zero crossing detector is used in some AC control circuits?
Zero crossing occurs when the line voltage is changing its polarity, from positive to negative, or vice versa. What I understand is, to fire the triac properly the firing circuit and the AC line should be synchronous. Is that the reason to use zero…
user16307
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acs37800 zero-crossing signal timing problem
I'm working on a project that is using ACS37800 for measuring current and voltage and for detecting zero-crossing.
However, there is some issues with the timing as the zero-crossing detection is off.
The ACS37800 has been setup with the…
teb
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Zero cross circuit exploded
would like to get a feedback on a zero cross circuit as it does not work.
Circuit is based on this.
240V AC, 50 Hz
Expect that C2 is 50V.
R1,R2, R4 are SMD.
After connecting to mains and measuring voltage across R1, the track between J1(Ac+) and R1…
flowian
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ZCD with LM358 not working
I've made this circuit to detect de zero cross but in out pin (pin 7) the voltage are about 3,7V fix. I've already measured pins 5 and 6 and the delta voltage ( vin+ and vin-) are inverting. I had inverted pins 5 and 6 and in this case pin7 is fixed…
Henrique
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