Philips 227E3QPHSU/27 Service Manual page 88

Meridian 3
88
3.15.4 Audio Amplifier
The amplifier shall provide two channels of audio up to 1.5 Watts per channel from 100Hz to 20 KHz,
based upon an audio signal input of 1.0Vrms per channel.
3.15.5 Volume Control
For monitors with a manual volume control, the direction (at the bottom) of the bezel volume control is
"-" key for minimum volume and "+" key for maximum volume. The default shipping position of the
volume control shall be approximately 90%.
3.15.6 Speaker Sensitivity
The speakers shall support a minimum sensitivity of 75dB+/-3dB at 2W/1m at 1 KHz.
3.15.7 Maximum Audio Card Output
The monitor audio amplifier shall accept a maximum input voltage of 1.5Vrms and meet the following
requirements at the maximum monitor volume setting.
1. The ratings of the audio amplifier may not be exceeded.
2. The ratings of the speakers may not be exceeded.
3. There must not be any clipping of the audio amplifier output signal.
Voltage dividers may be used to reduce the input signal level.
3.15.8 Monitor Audio Amplifier Input Impedance
The monitor audio amplifier shall have minimum 10KOHM AC input impedance.
3.16 Power Sensor (option)
Functional requirements for the front detection
For the presence sensor functionality, the following requirements are defined.
Two IRs used for user present detections, one IR is for transmission signals, the other one is for receiving
reflection IR signals.
User must be detected in the following range:
40 up to 100 cm (+ 20cm)
Detection angle:
+/-35 degree (for IR LED)
Sensor key control
Adjust detection distances (0~4 scales), default is 3 tolerances: (+/-10 cm)
0: OFF
1: 90 cm
2: 100 cm
3: 110 cm
4: >130 cm