The problems of the voltage fluctuation and degradation of the power factor in phase-shifting trigger have been solved with the technology of single-phase controllable silicon zero-crossing trigger in the temperature control system.

To reject higher harmonic produced in process of temperature adjusting,a zero-crossing triggering technic is put forward.

The AVR singlechip is used for the core of controller,the automatic compensation optimum control method is established based on reactive power compensation principle,the problem of thyristor switched wrong trigger is solved by the technology of zero crossing triggering,switched vibration i.

In this article,the authors discuss how to implement the full automatic real time compensation of reactive power using several methods:a)applying "Power Trac" module,b)acguiring the system parameters,c)connecting/disconnecting the capacitors block based on the reactive power of the system by means of zero crossing triggering of SCR components.

This article analyzed the principle of zero-cross-over triggering and introduced how to realize the software and hardware in the electric upsetting.

The system uses SPCE061A microprocessor to achieve temperature control,and it uses MOC3021 to achieve zero passage trigger.

The system use SOC microprocessor to actualize multi-channel temperature control,and it use DS1820 and MOC3041 to actualize temperature collection and synchronous zero passage trigger.

In this article,the analog-digital chip A/D574A,the zero-crossing flip-flop and MCS-51 single-chip microcomputer are used as a main control system to detect the vibration of electromagnetic vibration feeder for transportation material.