Samsung DV316LGW/XAA Service Manual page 77

▶ Function
Detects the current RPM of the motor and controls the output.
▶ Description
- The motor TACHO sensor is connected to CN10 B-pin.
- According to the current RPM of the motor, a square wave is applied to pin 8.
- The square wave that is input to TR2 BASE turns the motor on if high (5V), and turns it
off if low (0V). And this operation will be inverted to TACHO NET for a clear wave with no
noise.
- The signal is applied to MICOM pin 13. Then MICOM counts the frequency of the input signal
and detects the current RPM of the motor.
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