Zero Cross Detector Electronic Circuits

Zero Cross Detector Circuits
Last Updated on: Wednesday, June 02, 2021 01:44 PM

Circuits Designed by Dave Johnson, P.E.:

Wide Band Zero Cross Detector - This circuit was designed to convert a low Amplitude 40KHz signal into a clean square wave signal. It will work with inputs as small as 5mv peak-to-peak or as large as 3 volts peak to peak. The input frequency can range from a few kilohertz to about 150[. . . Circuit by David Johnson P.E., 02/18/06]
Zero-Cross Detector-Wide Band - This circuit was designed to convert a low Amplitude 40KHz signal into a clean square wave signal. It will work with inputs as small as 5mv peak-to-peak or as large as 3 volts peak to peak. The input frequency can range from a few kilohertz to about 152[ . . . Hobby Circuit designed by Dave Johnson P.E., 02/18/06]

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AC Power Line Synchronization Has Two Separate Outputs for Each Half-Period - 03/22/13 EDN Design Idea Generate independent short pulses at positive- and negative-going AC mains zero crossings. Often a measurement of weak signals has to be performed in the presence of strong interference from the ac power mains. If the interfering signal cannot be filtered out, then you can still obtain a clean result by making two consecutive measurements separated in time by an odd number of half-periods of the mains and calculating the average of the two measurements. The interfering signals have opposite polarities in consecutive measurements, and averaging cancels them out. If you average several consecutive pairs of measurements, the results will improve still further. [by Dusan Ponikvar]

Circuit for mains synchronization has two separate outputs for each half-period - 03/22/13 EDN Design Idea Generate independent short pulses at positive- and negative-going AC mains zero crossings. Often a measurement of weak signals has to be performed in the presence of strong interference from the ac power mains. If the interfering signal cannot be filtered out, then you can still obtain a clean result by making two consecutive measurements separated in time by an odd number of half-periods of the mains and calculating the average of the two measurements. The interfering signals have opposite polarities in consecutive measurements, and averaging cancels them out. If you average several consecutive pairs of measurements, the results will improve still further. [by Dusan Ponikvar]

Circuit yields accurate absolute values - 07/05/01 EDN Design Idea The circuit in Figure 1 delivers the absolute value of the input signal with an accuracy better than 10 ppm of the full-scale range. The circuit has low zero-crossing error. You can use it as an asynchronous demodulator, as a source [by Marco Pisani, Istituto di Metrologia G Colonnetti, Turin, Italy]

Low-component-count zero-crossing detector is Low-Power - 03/14/13 EDN Design Idea A simple opto-coupled circuit produces a logic level output signal synchronized to the power line. There are many circuits published showing zero-crossing detectors for use with 50- and 60-Hz power lines. Though the circuit variations are plentiful, many have shortcomings. This Design Idea shows a circuit that uses only a few commonly available parts and provides good performance with low power consumption. In the circuit shown in Figure 1, a waveform is produced at VO with rising edges that are synchronized with the zero crossings of the line voltage, VAC. The circuit can be easily modified so that it produces a falling-edge waveform that is synchronized with VAC. [by Carlos Castro-Miguens]

Mains Synchronization Has Two Separate Outputs for Each Half-Period - 03/22/13 EDN Design Idea Generate independent short pulses at positive- and negative-going AC mains zero crossings. Often a measurement of weak signals has to be performed in the presence of strong interference from the ac power mains. If the interfering signal cannot be filtered out, then you can still obtain a clean result by making two consecutive measurements separated in time by an odd number of half-periods of the mains and calculating the average of the two measurements. The interfering signals have opposite polarities in consecutive measurements, and averaging cancels them out. If you average several consecutive pairs of measurements, the results will improve still further. [by Dusan Ponikvar]

Mains-Driven Zero-Crossing Detector Uses Only A FeW High-Voltage Parts - 12/01/11 EDN Design Idea You can get isolation with low power consumption using this simple circuit. The circuit in this Design Idea generates a zero-crossing pulse off the ac mains and provides galvanic isolation. The falling edge of the output pulse happens at approximately 200 μsec before the zero crossing. You can use the circuit to safely stop the triggering of a thyristor gate, giving it time to properly turn off. The circuit generates short pulses only when the mains voltage is approximately 0V, thereby dissipating only 200 mW at 230V and a 50-Hz input. [by Luca Matteini, Agliana, Italy]

Paralleling decreases autozero-amplifier noise by a factor of two - 06/07/07 EDN Design Idea By simply paralleling four Amplifiers of a quad auto-zero amplifier, you can decrease output noise by a factor of two [by Marián Štofka, Slovak University of Technology, Bratislava, Slovakia]

Sample-And-Hold Amplifier Holds the Difference of Two Inputs - 07/24/08EDN Design Idea You can fulfill a requirement for sampling the difference of two signals in two classic ways. You can subtract the two input signals with an instrumentation Amplifier whose output connects to an input of a classic sample-and-hold [by Marián Štofka, Slovak University of Technology, Bratislava, Slovakia]

Self Powered Sine to Square Wave Converter - Converts sine to square waves without a power-source Useful as a test instrument for audio purposes [Flavio Dellepiane's web site]

Synchronization Has Two Separate Outputs for Each Half-Period - 03/22/13 EDN Design Idea Generate independent short pulses at positive- and negative-going AC mains zero crossings. Often a measurement of weak signals has to be performed in the presence of strong interference from the ac power mains. If the interfering signal cannot be filtered out, then you can still obtain a clean result by making two consecutive measurements separated in time by an odd number of half-periods of the mains and calculating the average of the two measurements. The interfering signals have opposite polarities in consecutive measurements, and averaging cancels them out. If you average several consecutive pairs of measurements, the results will improve still further. [by Dusan Ponikvar]

Time-tag impulses with zero-crossing circuit - 01/24/02 EDN Design Idea A "constant-fraction discriminator" usually performs the time-tagging of impulsive events, which have a peaking time of the signal Amplitude. The implementation of this technique requires a delay in the input signal of approximatel [by Elio Rossi, Itesre-CNR, Bologna, Italy]

Wide Band Zero Cross Detector - This circuit was designed to convert a low Amplitude 40KHz signal into a clean square wave signal. It will work with inputs as small as 5mv peak-to-peak or as large as 3 volts peak to peak. The input frequency can range from a few kilohertz to about 150[. . . Circuit by David Johnson P.E., 02/18/06]

Yield Accurate Absolute Values - 07/05/01 EDN Design Idea The circuit in Figure 1 delivers the absolute value of the input signal with an accuracy better than 10 ppm of the full-scale range. The circuit has low zero-crossing error. You can use it as an asynchronous demodulator, as a source [by Marco Pisani, Istituto di Metrologia G Colonnetti, Turin, Italy]

Zero-Cross Detector-Wide Band - This circuit was designed to convert a low Amplitude 40KHz signal into a clean square wave signal. It will work with inputs as small as 5mv peak-to-peak or as large as 3 volts peak to peak. The input frequency can range from a few kilohertz to about 152[ . . . Hobby Circuit designed by Dave Johnson P.E., 02/18/06]

Zero-Crossing Circuit Avoids AC Noise - To properly control AC sources using solid-state devices, you need a pulse to signal the start of the AC’s rising edge. Most of the time, however, tremendous noise levels plague power lines. There needs to [Nick Ierfino, Concordia University-Circuit Designer]

Zero-Crossing Detector - [Advanced Linear Devices, Inc]

Zero-Crossing Detector Uses Only A FeW High-Voltage Parts - 12/01/11 EDN Design Idea You can get isolation with low power consumption using this simple circuit. The circuit in this Design Idea generates a zero-crossing pulse off the ac mains and provides galvanic isolation. The falling edge of the output pulse happens at approximately 200 μsec before the zero crossing. You can use the circuit to safely stop the triggering of a thyristor gate, giving it time to properly turn off. The circuit generates short pulses only when the mains voltage is approximately 0V, thereby dissipating only 200 mW at 230V and a 50-Hz input. [by Luca Matteini, Agliana, Italy]

Zero Cross Detector Circuits