Circuit to avoid singeing of thermometer contacts a

In order to prevent electrical contact pressure thermometer contact singeing failure, the best way is to improve the working mode of the contacts, as
shown in Figure 11-60. That is, connect two unidirectional thyristors (during DC control ) or two bidirectional thyristors (during AC control) to the output end of the meter
, and the contacts of the electrical contact pressure thermometer only control the control electrode of the thyristor .