Zero Cross Detector Electronic Circuits

Zero Cross Detector Circuits
Last Updated on: Friday, March 12, 2010 12:07 PM

Circuits Designed by Dave Johnson, P.E.:

40KHz Ultrasound Receiver
A X100 transistor amplifier is followed by a zero cross detector circuit, using a voltage comparator. The output is a TTL logic signal, corresponding to the received 40KHz signal. (added 7/06)

LINE POWERED 60Hz CLOCK GENERATOR
This circuit is connected to the 120vac power line and transfers 60Hz clock pulses to a logic circuit. The optoisolator used provides 5000 volts of isolation between the power line and the logic side of the circuit.

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 150KHz.

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

40kHz Ultrasound Receiver - A X100 transistor amplifier is followed by a zero cross detector circuit, using a voltage comparator. The output is a TTL logic signal, corresponding to the received 40KHz signal. (added 7/06) ….(designed by David A. Johnson)

Circuit Yields Accurate Absolute Values - 07/05/01 EDN-Design Ideas: 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 for logarithmic amplifiers, or simply as a demonstration of the wonders of.....(design idea added 6/03)

Line Powered 60hz Clock Generator - This circuit is connected to the 120vac power line and transfers 60Hz clock pulses to a logic circuit. The optoisolator used provides 5000 volts of isolation between the power line and the logic side of the circuit. ….(designed by David A. Johnson)

Paralleling decreases autozero amplifier noise by a factor of two - 06/07/07 EDN-Design Ideas: By simply paralleling four amplifiers of a quad auto-zero amplifier, you can decrease output noise by a factor of two.....(design idea added 9/08)

Sample / Hold Has Zero Droop & Infinite Hold - Maxim Application Notes / 12 / Jul-08 (app note added 5/08)

Sample and Hold Amplifier - ….(circuit design added 02/09)

Sample and hold amplifier holds the difference of two inputs - 07/24/08 EDN-Design Ideas: A sample-and-hold amplifier tracks and holds the difference of two input signals.....(design idea added 09/08)

Self Powered Sine to Square Wave Converter - Converts sine to square waves without a power-source Useful as a test instrument for audio purposes (added 9/04)

Time Tag Impulses with Zero Crossing Circuit - 01/24/02 EDN-Design Ideas: 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 approximately the same amount as the signal's rise time.... / (schematic / circuit added 11/03)

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 150KHz. ….(designed by David A. Johnson)

Zero crossing AC switch oscillator - The circuit shown will switch on and off a resistive or inductive load up to 800VA with the possibility to adjust both the on and off period. Switching takes place during the zero crossing of the sine wave. The switch on point is around the zero crossing but ....(added 9/07)

Zero Crossing Detector - (app note added 6/06)

Zero-TC Reference Diodes - MicroNote 205 from Microsem (app note added 6/06)