U211B Datasheet, PDF (27/30 Pages) ATMEL Corporation – Phase Control IC with Overload Limitation for Tacho Applications

U211B
The schematic diagram (see Figure 10-22 on page 26) is designed as a speed control IC based
on the reflection-coupled principle with 4 periods per revolution and a maximum speed of
30000 rpm. The separation of the coupler from the rotating aperture should be about approxi-
mately 1 mm. In the schematic diagram, the power supply for the coupler was provided
externally because of the relatively high current consumption.
Instructions for adjusting:
1. In the initial adjustment of the phase-control circuit, R₂ should be adjusted so that when
R₁₄ = 0 and R₃₁ are in minimum position, the motor just turns.
2. The speed can now be adjusted as desired by means of R₃₁ between the limits deter-
mined by R₁₃ and R₁₄.
3. The switch-off power of the limiting-load control can be set by R₉. The lower R₉, the
higher the switch-off power.
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4752B–INDCO–09/05