Application of TCA785 in temperature control system

Typical Application Examples Due to the excellent performance of TCA785, it
can be easily used in main circuits with a single thyristor or transistor, single-phase half-controlled bridge, fully
controlled bridge, three-phase half-controlled bridge, fully controlled bridge and other main circuit types.
Trigger thyristors or transistors in power electronic equipment to achieve
the purposes of temperature control, voltage regulation, DC speed regulation, AC speed regulation, DC power transmission, etc. required by users . Due to space limitations, this article only gives a few examples to illustrate
its applications.
    (1) Used in temperature control systems. Temperature control is widely used in the field of power electronics technology
, such as diffusion and sintering in the manufacturing process of power electronic devices such as thyristors and transistors
; thermal fatigue and high temperature blocking tests for thyristor factory life testing, etc., all
require accurate Temperature control, Figure 12-8 shows the detailed circuit diagram
of TCA785 used to trigger the bidirectional thyristor to control temperature in this type of system
. In the figure, the Q and Q pulses
output by TCA785 are used to directly control the temperature in the positive and negative half cycles of the AC power supply. Triggering the thyristor, the phase-shifted control voltage Vl comes from the output of the temperature regulator TA . The TCA785 's own working power supply is directly obtained by the grid voltage half-transition rectification filtering and voltage stabilization by the voltage regulator tube. This structure eliminates the need for conventional The control transformer simplifies the entire circuit, and the temperature feedback is obtained using a temperature sensor, so this temperature control system has higher temperature control accuracy.