U211B2 Datasheet, PDF (15/20 Pages) TEMIC Semiconductors – Phase Control Circuit - General Purpose Feedback

U211B2/ B3
Figure 24. Speed control, automatic retriggering, load switch-off, soft-start
The maximum load regulation shows the principle in the
same speed dependency as the original version (see
figure 2). When reaching the maximum load, the control
unit is turned to a_max, adjustable with R₂. Then only I_O
flows. This function is effected by the thyristor, formed
by T₁ and T₂ which ignites as soon as the voltage at Pin 15
reaches ca. 6.8 V (Reference point Pin 16). The potential
at Pin 15 is lifted and kept by R₁₄ over the internally
operating threshold whereby the maximum load
regulation starts and adjusts the control unit constantly to
a_max (I_O), inspite of a reduced load current. The motor
shows that the circuit is still in operation by a quiet
buzzing noise.
TELEFUNKEN Semiconductors
Rev. A1, 29-May-96
15 (20)