Color Wheel Circuit Block
Diagram
Refer to Figure 12. The color wheel operation can be understood by dividing the color
wheel operation into the inputs (at L3) and the signal output (at L2). Notice that the
color wheel assembly also contains the TV’s temperature sensor (IC6904) that governs
the voltage applied to two fans (not shown).
Figure 12 - Color Wheel Block
Color Wheel Motor Drive (Inputs)
Refer to figure 12. The color wheel is driven by a 3-phase motor in the color wheel
assembly but powered by IC6011 on the L board. All three-phase motor drive inputs
can be monitored at connector L3. See table 7. If one of the three drive signals is
missing, the motor makes a ticking sound instead of a normal whirling sound as it spins.
Color Wheel 3 phase Motor Drive Voltages
L3/Pin
DC Voltage
Vp-p
Frequency *
Description
1
9.5Vdc
2Vp-p + 5Vspikes
--------
Common
2
9.5Vdc
5Vp-p + 8V spikes 738 Hz
Phase 1
3
9.5Vdc
5Vp-p + 8V spikes 738 Hz
Phase 2
4
9.5Vdc
5Vp-p + 8V spikes 738 Hz
Phase 3
*
Frequency varies with input signal.
Table
7
The default speed of the color wheel without sync input (unused input selected) is 185
Hz. When video is input, the sync signal locks the motor speed at 180 Hz (5 Hz lower).
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