Index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Home > Zero cross circuit

A zero cross circuit is an electrical circuit that starts operation with the AC load voltage at close to zero-phase. This is in relation to solid state relays, such as triacs and silicon controlled rectifiers. The purpose of the circuit is to start the controlled triac conducting as soon as possible, so that the input and output voltages and waveforms are as close as possible. This is useful when the triac is used to control outlets, motors, ballasted lights, or other loads where voltage drops or waveform clipping could cause ill effects.

The point where the line voltage is 0V is the Zero Cross Point. When a triac is connected in its simplest form, it can clip the beginning of the voltage curve, due to the minimum gate voltage of the triac. A zero cross circuit works to correct this problem, so that the triac functions as well as possible. This is typically done with thyristors in two of the three phases.

Many opto-triacs come with zero cross circuits built in. They are often used to control larger, power triacs. In this setup triac turn-on delays will compound, so quick turn on times are important.

The corresponding phase angle circuits are more sophisticated and more expensive then zero cross circuits.

This article is a stub. You can help Wikipedia by [ ṣlocalurl: : |action=edit}} expanding it].

Electrical circuits

Read more »

<Hide>

Topics: Zero Cross Circuit, Zero sum, Zeroth, Zero bit Insertion...

Zero-sumZero-sum describes a situation in which a participant's gain (or loss) is exactly balanced by the losses (or gains) of the other participant(s). It is so named because when you add up the total gains of the participants and subtract the total losses then	ZerothThe zeroth item is the initial item of a sequence, if that sequence is numbered beginning from zero rather than one. In that case, when using the word "first", it should be made clear whether the common meaning "initial" is meant, or the special meaning "	Zero-bit insertionZero-bit insertion is a bit-stuffing technique used in data transmission protocols to ensure that six consecutive "1" bits never appear between the two flags that define the beginning and the ending of a transmission frame. When five consecutive "1" bits
Zero dBm transmission level pointZero dBm transmission level point (0 dBm TLP): In a communication system, a point at which the reference level is 1 mW, i. Note: The actual power level of the communications traffic is not necessarily 0 dBm. It is usually below the reference level. The re	Zero-dispersion slopeZero-dispersion slope In a single-mode optical fiber, the rate of change of dispersion, with respect to wavelength, at the fiber's zero-dispersion wavelength. Note 1: In silica-based optical fibers, the zero-dispersion wavelength occurs at approximately 1	Zero-dispersion wavelengthIn telecommunication, the term zero-dispersion wavelength has the following meanings: 1. In a single-mode optical fiber, the wavelength or wavelengths at which material dispersion and waveguide dispersion cancel one another. Note: In all silica-based opti
Zero Wing	Zero divisor	Zero-coupon bond
Zero-point energy	Zéro de Conduite	Zero-ists
Zero-player game	Zero sharp	Zeroth law of thermodynamics

Non User